Robust coordination of cardiac functions from gene co-expression reveals a versatile combinatorial transcriptional control.

The necessary overall coordination of cardiac cellular functions is little known at the mRNA level. Focusing on energy production and cardiac contraction, we analyzed microarray data from heart tissue obtained in groups of mice and rats in normal conditions and with a left ventricular dysfunction. In each group and for each function, we identified genes positively or negatively correlated with numerous genes of the function, which were called coordinated or inversely coordinated with the function.

The microRNA signature in response to insulin reveals its implication in the transcriptional action of insulin in human skeletal muscle and the role of a sterol regulatory element-binding protein-1c/myocyte enhancer factor 2C pathway.

Objective: Factors governing microRNA expressions in response to changes of cellular environment are still largely unknown. Our aim was to determine whether insulin, the major hormone controlling whole-body energy homeostasis, is involved in the regulation of microRNA expressions in human skeletal muscle.

Research Design And Methods: We carried out comparative microRNA (miRNA) expression profiles in human skeletal muscle biopsies before and after a 3-h euglycemic-hyperinsulinemic clamp, with TaqMan low-density arrays.

Functional meta-analysis of double connectivity in gene coexpression networks in mammals.

In functional genomics, the high-throughput methods such as microarrays 1) allow analysis of the relationships between genes considering them as elements of a network and 2) lead to biological interpretations thanks to Gene Ontology. But up to now it has not been possible to find relationships between the functions and the connectivity of the genes in coexpression networks. To achieve this aim, we have defined a double connectivity for each gene by the numbers of its significant negative and positive correlations with the other genes within a given biological condition, or group.

Transcriptional alterations in the left ventricle of three hypertensive rat models.

Left ventricular hypertrophy (LVH) is commonly associated with hypertension and represents an independent cardiovascular risk factor. The aim of this study was to test the hypothesis that the cardiac overload related to hypertension is associated to a specific gene expression pattern independently of genetic background. Gene expression levels were obtained with microarrays for 15,866 transcripts from RNA of left ventricles from 12-wk-old rats of three hypertensive models [spontaneously hypertensive rat (SHR), Lyon hypertensive rat (LH), and heterozygous TGR(mRen2)27 rat] and their respective controls.

Blood pressure and heart rate variability changes during cardiac surgery with cardiopulmonary bypass.

This study investigated patients undergoing elective cardiac surgery to evaluate the effects of cardiopulmonary bypass (CPB) on the spontaneous variability of mean arterial pressure (MAP) and heart rate (HR). Forty-one adult patients receiving different cardiovascular system drugs were included in the study. Patients were divided into three groups: no preoperative pharmacological cardiovascular treatment (n = 12), beta-blocker (BB) (n = 13), and angiotensin-converting enzyme inhibition (ACEI) (n = 16).

Sodium intake and blood pressure in healthy individuals.

Objective: To investigate further the relationships between blood pressure and sodium intake, which have been claimed to exist, but have not been clearly established, in epidemiological studies.

Design And Participants: A 2-year follow up study of a cohort of 296 healthy volunteers working in the same company.

Results: Consistent with previously reported findings, covariance analysis in the entire population, including multivariate analysis to examine the potential influence of confounding variables, failed to identify a significant relationship between blood pressure and sodium intake or between their respective changes within 2 years.