YKL-40 is elevated in patients with peripheral arterial disease and diabetes or pre-diabetes

ObjectiveYKL-40 is secreted by macrophages in atherosclerotic lesions and involved in plaque rupture. YKL-40 is elevated in coronary artery disease, and predicts cardiovascular mortality. Experimental in vivo and in vitro data suggest a role of YKL-40 in tissue remodeling. A disease modulating potency of YKL-40 was not investigated in peripheral arterial disease (PAD).MethodsWe measured YKL-40 in 460 subjects: 316 PAD: 71 normal glucose metabolism (PAD-NGM), 90 pre-diabetes (PAD-PREDM) and 155 diabetes (PAD-DM); 20 diabetes with atherosclerosis but without PAD (AS-DM); 85 diabetes without macro-vascular complications (DM) and 39 healthy controls (CO).ResultsYKL-40 is higher in PAD vs. CO (median [25–75 percentile]: 103 [69–159] vs. 43 [30–80] ng/ml; p < 0.001). In addition, YKL-40 is elevated in DM (p < 0.001), PAD-NGM (p = 0.001), PAD-PREDM (p < 0.001), PAD-DM (p < 0.001) and AS-DM (p = 0.002) compared to CO. Among PAD, YKL-40 is increased in PAD-PREDM (p = 0.001) and PAD-DM (p = 0.01) vs. PAD-NGM. By multivariate regression YKL-40 is significantly associated with age (beta = 0.272), triglycerides (beta = 0.216), aspartate-amino-transferase (beta = 0.177) and c-reactive-protein (beta = 0.178). Underpinning its role YKL-40 was found to be associated with micro-/macroalbuminuria (p = 0.014/p = 008) – a strong remodeling inducer. In addition, YKL-40 was elevated in existence of mediasclerosis (p = 0.008), a remodeling process.ConclusionWe are first to show that YKL-40 is higher in subjects with peripheral arterial disease. YKL-40 was higher in PAD patients with pre-/diabetes. In addition, YKL-40 was associated with the “severity” of generalized atherosclerosis estimated by affected vascular beds. All our findings point towards a role of YKL-40 in the progression/prognosis of patients with PAD and concomitant diabetes.     

Transcriptional consequences of aneuploidy

Aneuploidy, or an aberrant karyotype, results in developmental disabilities and has been implicated in tumorigenesis. However, the causes of aneuploidy-induced phenotypes and the consequences of aneuploidy on cell physiology remain poorly understood. We have performed a metaanalysis on gene expression data from aneuploid cells in diverse organisms, including yeast, plants, mice, and humans. We found highly related gene expression patterns that are conserved between species: genes that were involved in the response to stress were consistently upregulated, and genes associated with the cell cycle and cell proliferation were downregulated in aneuploid cells. Within species, different aneuploidies induced similar changes in gene expression, independent of the specific chromosomal aberrations. Taken together, our results demonstrate that aneuploidies of different chromosomes and in different organisms impact similar cellular pathways and cause a stereotypical antiproliferative response that must be overcome before transformation.     

Insulin is essential for in vitro chondrogenesis of mesenchymal progenitor cells and influences chondrogenesis in a dose-dependent manner

Purpose

Insulin is a commonly used additive in chondrogenic media for differentiating mesenchymal stem cells (MSCs). The indispensability of other bioactive factors like TGF-β or dexamethasone in these medium formulations has been shown, but the role of insulin is unclear. The purpose of this study was to investigate whether insulin is essential for MSC chondrogenesis and if there is a dose-dependent effect of insulin on MSC chondrogenesis.

Methods

We cultivated human MSCs in pellet culture in serum-free chondrogenic medium with insulin concentrations between 0 and 50 μg/ml and assessed the grade of chondrogenic differentiation by histological evaluation and determination of glycosaminoglycan (GAG), total collagen and DNA content. We further tested whether insulin can be delivered in an amount sufficient for MSC chondrogenesis via a drug delivery system in insulin-free medium.

Results

Chondrogenesis was not induced by standard chondrogenic medium without insulin and the expression of cartilage differentiation markers was dose-dependent at insulin concentrations between 0 and 10 μg/ml. An insulin concentration of 50 μg/ml had no additional effect compared with 10 μg/ml. Insulin was delivered by a release system into the cell culture under insulin-free conditions in an amount sufficient to induce chondrogenesis.

Conclusions

Insulin is essential for MSC chondrogenesis in this system and chondrogenic differentiation is influenced by insulin in a dose-dependent manner. Insulin can be provided in a sufficient amount by a drug delivery system. Therefore, insulin is a suitable and inexpensive indicator substance for testing drug release systems in vitro.     

Relation of melody complexity in infants' cries to language outcome in the second year of life: A longitudinal study

This study is part of the German Language Development Study's prospective longitudinal research programme on infants from birth until the age of 3 years. Thirty‐four infants were retrospectively classified into two groups (normal/delayed) by their language skills at 2.5 years of age. Frequency spectrograms and melodies of about 11,000 cries from the first 16 weeks of life were analysed using a CSL 4400. A Melody Complexity Index was calculated at monthly intervals. Infants with less than 45% complex melodies in their cries during the second month were found to be almost five times more likely to develop a language delay as infants with a higher proportion. For infants above the cut‐off of .45, development of a language delay condition could be ruled out with a probability of 89%. Although the results need to be interpreted cautiously, the data indicate a possible relation between early melody development and later language outcome.