Nonischemic cardiomyopathy (NICM) resulting from long-standing hypertension, valvular disease, and genetic mutations is a major cause of heart failure worldwide. Recent observations suggest that myeloid cells can impact cardiac function, but the role of tissue-intrinsic vs. tissue-extrinsic myeloid cells in NICM remains poorly understood. Here, we show that cardiac resident macrophage proliferation occurs within the first week following pressure overload hypertrophy (POH; a model of heart failure) and is requisite for the heart's adaptive response. Mechanistically, we identify Kruppel-like factor 4 (KLF4) as a key transcription factor that regulates cardiac resident macrophage proliferation and angiogenic activities. Finally, we show that blood-borne macrophages recruited in late-phase POH are detrimental, and that blockade of their infiltration improves myocardial angiogenesis and preserves cardiac function. These observations demonstrate previously unappreciated temporal and spatial roles for resident and nonresident macrophages in the development of heart failure.

Objective: The purpose of this study was to compare the penetration of 808 and 980 nm laser light through bovine tissue samples 18-95 mm thick. Background data: Low-level laser therapy (LLLT) is frequently used to treat musculoskeletal pathologies. Some of the therapeutic targets are several centimeters deep. Methods: Laser light at 808 and 980 nm (1 W/cm 2 ) was projected through bovine tissue samples ranging in thickness from 18 to 95 mm. Power density measurements were taken for each wavelength at the various depths. Results: For 808 nm, 1 mW/cm 2 was achieved at 3.4 cm, but for 980 nm, 1 mW/cm 2 was achieved at only 2.2 cm depth of tissue. Conclusions: It was determined that 808 nm of light penetrates as much as 54% deeper than 980 nm light in bovine tissue.

Placental development results from a highly dynamic differentiation program. We used DNA microarray analysis to characterize the process by which human cytotrophoblast cells differentiate into syncytiotrophoblast cells in a purified cell culture system. Of 6,918 genes analyzed, 141 genes were induced and 256 were downregulated by more than 2-fold. Dynamically regulated genes were divided by the K-means algorithm into 9 kinetic pattern groups, then by biologic classification into 6 overall functional categories: cell and tissue structural dynamics, cell cycle and apoptosis, intercellular communication, metabolism, regulation of gene expression, and expressed sequence tag (EST) and function unknown. Gene expression changes within key functional categories were tightly coupled to morphological changes. In several key gene function categories, such as cell and tissue structure, many gene members of the category were strongly activated while others were strongly repressed. These findings suggest that differentiation is augmented by "categorical reprogramming" in which the function of induced genes is enhanced by preventing the further synthesis of categorically related gene products.

The profound effects of 17beta-estradiol on cell growth, differentiation, and general homeostasis of the reproductive and other systems, are mediated mostly by regulation of temporal and cell type-specific expression of different genes. In order to understand better the molecular events associated with the activation of the estrogen receptor (ER), we have used microarray technology to determine the transcriptional program and dose-response characteristics of exposure to a potent synthetic estrogen, 17 alpha-ethynyl estradiol (EE), during prepubertal development. Changes in patterns of gene expression were determined in the immature uterus and ovaries of Sprague-Dawley rats on postnatal day (PND) 24, 24 h after exposure to EE, at 0.001, 0.01, 0.1, 1 and 10 micro g EE/kg/day (sc), for four days (dosing from PND 20 to 23). The transcript profiles were compared between treatment groups and controls using oligonucleotide arrays to determine the expression level of approximately 7000 annotated rat genes and over 1740 expressed sequence tags (ESTs). Quantification of the number of genes whose expression was modified by the treatment, for each of the various doses of EE tested, showed clear evidence of a dose-dependent treatment effect that follows a monotonic response, concordant with the dose-response pattern of uterine wet-weight gain and luminal epithelial cell height. The number of genes whose expression is affected by EE exposure increases according to dose. At the highest dose tested of EE, we determined that the expression level of over 300 genes was modified significantly (p < or = 0.0001). A dose-dependent analysis of the transcript profile revealed a set of 88 genes whose expression is significantly and reproducibly modified (increased or decreased) by EE exposure (p < or = 0.0001). The results of this study demonstrate that, exposure to a potent estrogenic chemical during prepubertal maturation changes the gene expression profile of estrogen-sensitive tissues. Furthermore, the products of the EE-regulated genes identified in these tissues have a physiological role in different intracellular pathways, information that will be valuable to determine the mechanism of action of estrogens. Moreover, those genes could be used as biomarkers to identify chemicals with estrogenic activity.

The purpose of this study was to determine (1) the transcriptional program elicited by exposure to three estrogen receptor (ER) agonists: 17 alpha-ethynyl estradiol (EE), genistein (Ges), and bisphenol A (BPA) during fetal development of the rat testis and epididymis; and (2) whether very low dosages of estrogens (evaluated over five orders of magnitude of dosage) produce unexpected changes in gene expression (i.e., a non-monotonic dose-response curve). In three independently conducted experiments, Sprague-Dawley rats were dosed (sc) with 0.001-10 microg EE/kg/day, 0.001-100 mg Ges/kg/day, or 0.002-400 mg BPA/kg/day. While morphological changes in the developing reproductive system were not observed, the gene expression profile of target tissues were modified in a dose-responsive manner. Independent dose-response analyses of the three studies identified 59 genes that are significantly modified by EE, 23 genes by Ges, and 15 genes by BPA (out of 8740), by at least 1.5 fold (up- or down-regulated). Even more genes were observed to be significantly changed when only the high dose is compared with all lower doses: 141, 46, and 67 genes, respectively. Global analyses aimed at detecting genes consistently modified by all of the chemicals identified 50 genes whose expression changed in the same direction across the three chemicals. The dose-response curve for gene expression changes was monotonic for each chemical, with both the number of genes significantly changed and the magnitude of change, for each gene, decreasing with decreasing dose. Using the available annotation of the gene expression changes induced by ER-agonist, our data suggest that a variety of cellular pathways are affected by estrogen exposure. These results indicate that gene expression data are diagnostic of mode of action and, if they are evaluated in the context of traditional toxicological end-points, can be used to elucidate dose-response characteristics.

Syncytin, a protein encoded by an envelope gene of a human endogenous retrovirus-W (HERV-W), plays a critical role in trophoblast differentiation. We isolated the 5'-flanking region of the syncytin gene from human genomic DNA by PCR and identified cis-acting elements on the promoter that are important for transcription. The major transcription initiation site identified by mung bean nuclease protection assays is 56 base pairs (bp) downstream from a putative CCAAT box. Deletion analysis of the 5'-flanking region of the syncytin gene indicated that the proximal 148 bp are essential for minimal promoter activity and that regions of the promoter from nt -1519 to -984 and nt -294 to -148 are required for maximal expression in normal trophoblast cells. DNase I footprint analysis of the region between nt -252 and +110 revealed three protected regions, FP1-FP3. Mutagenesis of a hepatocyte-specific nuclear protein-1 (HAPF1) binding site in FP1 and a TATA box in FP3 had no effects on basal promoter activity. However, mutation of the CCAAT motif and the octamer protein (Oct) binding site in FP2 decreased promoter activity by 88% and 76%, respectively. Mutation of the ecdysone receptor (EcR) response element in FP2, which may bind a nuclear hormone receptor, increased basal promoter activity by 2-fold. Gel shift and supershift assays indicated that CCAAT-binding factor (CBF) binds to the CCAAT motif and that Oct binds to the Oct binding site. Taken together, these findings indicate that the syncytin promoter is located in the 5' long terminal repeat (LTR) of the HERV-W gene and that binding sites for CBF and Oct in the proximal promoter are critical for transcriptional regulation of the gene in trophoblast cells.

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