BackgroundAfrican Americans suffer from disproportionately high rates of hypertension and cardiovascular disease. Psychosocial stress, lifestyle and telomere dysfunction contribute to the pathogenesis of hypertension and cardiovascular disease. This study evaluated effects of stress reduction and lifestyle modification on blood pressure, telomerase gene expression and lifestyle factors in African Americans.MethodsForty-eight African American men and women with stage I hypertension who participated in a larger randomized controlled trial volunteered for this substudy. These subjects participated in either stress reduction with the Transcendental Meditation technique and a basic health education course (SR) or an extensive health education program (EHE) for 16 weeks. Primary outcomes were telomerase gene expression (hTERT and hTR) and clinic blood pressure. Secondary outcomes included lifestyle-related factors. Data were analyzed for within-group and between-group changes.ResultsBoth groups showed increases in the two measures of telomerase gene expression, hTR mRNA levels (SR: p< 0.001; EHE: p< 0.001) and hTERT mRNA levels (SR: p = 0.055; EHE: p< 0.002). However, no statistically significant between-group changes were observed. Both groups showed reductions in systolic BP. Adjusted changes were SR = -5.7 mm Hg, p< 0.01; EHE = -9.0 mm Hg, p < 0.001 with no statistically significant difference between group difference. There was a significant reduction in diastolic BP in the EHE group (-5.3 mm Hg, p< 0.001) but not in SR (-1.2 mm Hg, p = 0.42); the between-group difference was significant (p = 0.04). The EHE group showed a greater number of changes in lifestyle behaviors.ConclusionIn this pilot trial, both stress reduction (Transcendental Meditation technique plus health education) and extensive health education groups demonstrated increased telomerase gene expression and reduced BP. The association between increased telomerase gene expression and reduced BP observed in this high-risk population suggest hypotheses that telomerase gene expression may either be a biomarker for reduced BP or a mechanism by which stress reduction and lifestyle modification reduces BP.Trial RegistrationClinicalTrials.gov NCT00681200

The inhibition of photosynthetic phosphorylation in spinach chloroplasts by vV-ethylmaleimide (MalNEt) was previously found to be light dependent. Under conditions where MalNEt inhibited photophosphorylation, light markedly enhanced the incorporation of [3H]MalNEt into coupling factor one (CFi) in chloroplasts previously incubated with unlabeled MalNEt in the dark. Only one of the five subunits of CFb as detected by acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, contained significant amounts of radioactive MalNEt. Uncouplers, such as ammonium chloride and carbonyl cyanide w-chlorophenylhydrazone, abolished the light-dependent inhibition of phosphorylation by MalNEt and largely prevented the light-

Three nuclear factors, the Ah receptor, XF1, and XF2, bind sequence specifically to the Ah response elements or xenobiotic response elements (XREs) of the cytochrome P450IA1 (P450c) gene. The interactions of these factors with the Ah response element XRE1 were compared by three independent methods, methylation interference footprinting, orthophenanthroline-Cu+ footprinting, and mobility shift competition experiments, using a series of synthetic oligonucleotides with systematic alterations in the XRE core sequence. These studies established the following (i) all three factors interact sequence specifically with the core sequence of XREI; (ii) the pattern of contacts made with this sequence by the Ah receptor are different from those made by XF1 and XF2; and (iii) although XF1 and XF2 can be distinguished by the mobility shift assay, the sequence specificities of their interactions with XRE1 are indistinguishable. Further characterization revealed the following additional differences among these three factors: (i) XF1 and XF2 could be extracted from nuclei under conditions quite different from those required for extraction of the Ah receptor; (ii) XF1 and XF2 were present in the nuclei of untreated cells and did not respond to polycyclic compounds, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and I-napthoflavone, while nuclear Ah receptor was undetectable in untreated cells and rapidly increased in response to TCDD; (iii) inhibition of protein synthesis did not affect the TCDD-induced appearance of the Ah receptor but substantially decreased the constitutive activities of XF1 and XF2, suggesting that the Ah receptor must be present in untreated cells in an inactive form that can be rapidly activated by polycyclic compounds, while the constitutive expression of XF1 and XF2 depends on the continued synthesis of a relatively unstable protein; (iv) the receptor-deficient and nuclear translocation-defective mutants of the hepatoma cell line Hepal, which are known to lack nuclear Ah receptor, expressed normal levels of XF1 and XF2, suggesting that the former factor is genetically distinct from the latter two; and (v) a divalent metal ion, probably Zn2+, is known to be an essential cofactor for the Ah receptor but was not required for the DNA-binding activities of XFI and XF2. Together, these findings indicate that the Ah receptor is distinct from XF1 and XF2, while the latter two activities may be related. Because the DNA-binding domains of these three factors overlap substantially, their binding to XREs is probably mutually exclusive, which suggests that the interplay of these factors at Ah response elements may be important to the regulation of CYPIAI gene transcription. The results of preliminary transfection experiments with constructs harboring XREs upstream of the chloramphenicol acetyltransferase gene driven by a minimal simian virus 40 promoter are presented that are consistent with this hypothesis. Cytochrome P450IA1 (see Nebert et al. [34] for current P450 nomenclature) catalyzes the mixed-function oxida...

Two cloned cDNAs derived from the mRNA for cell fibronectin have been sequenced, providing evidence that transcription with AMV reverse transcriptase or Escherichia coli DNA polymerase I may not always result in double stranded cDNA that is exactly homologous with its mRNA template. Instead, the sequences of these cloned cDNAs are consistent with the duplication and rearrangement of sequences during synthesis of double stranded cDNA. INTRODUCTIONWe have constructed a set of recombinant plasmids with inserts complementary to the fibronectin mRNA (1). Cell fibronectin plays important roles in cell adhesion and in maintaining normal cell morphology (2-4).