Project description:Modification of Gene Expression of Skeletal Muscle in Response to postmenopause with or without Hormone Replacement Therapy. Even though menopause is often accompanied with first signs of age-associated changes in muscle structure and function, the effects of hormone replacement therapy (HRT) or menopause-related decline in estrogen production in the muscles of postmenopausal women is not well understood. We have used a randomized double-blinded study design together with an explorative microarray experiment to characterize possible effects of continuous, combined HRT and estrogen deprivation on the skeletal muscle of fifteen early postmenopausal women from which 10 used HRT and 5 used placebo for 12-months in a douple-blinded design. Keywords: time course analysis from HRT users and non-users comparison of gene expression in skeletal muscle of healthy postmenopausel women using HRT (n=10) vs not-using HRT (n=5)
Project description:Modification of Gene Expression of Skeletal Muscle in Response to postmenopause with or without Hormone Replacement Therapy. Even though menopause is often accompanied with first signs of age-associated changes in muscle structure and function, the effects of hormone replacement therapy (HRT) or menopause-related decline in estrogen production in the muscles of postmenopausal women is not well understood. We have used a randomized double-blinded study design together with an explorative microarray experiment to characterize possible effects of continuous, combined HRT and estrogen deprivation on the skeletal muscle of fifteen early postmenopausal women from which 10 used HRT and 5 used placebo for 12-months in a douple-blinded design. Keywords: time course analysis from HRT users and non-users
Project description:The American Women's Health Initiative study published in July 2002 caused considerable concern among hormone replacement therapy (HRT) users and prescribers in many countries. This study is an exploratory research comparing the genome wide expression profile in whole blood samples according to HRT use. Within the Norwegian Women and Cancer study, 100 postmenopausal women (50 HRT users and 50 non-HRT users) born between 1943 and 1949 with normal to high body mass index and no other medication use were selected. After total RNA extraction, amplification and labelling, the samples were hybridized together with a common reference (Universal human reference RNA, Stratagen) to Agilent Human 1A oligoarrays (G4110b, Agilent Technologies, Palo Alto, CA) containing 20,173 unique genes. Differentially expressed genes were used to build a classifier using the nearest shrunken centroids method (PAM). Then, we tested the significant changes in single genes by different methods like t-test, Significance Analysis of Microarrays (SAM) and Bayesian ANOVA analysis (BAM). Results did not reveal any distinct gene list which predicted accurately HRT exposure (error rate = 0.45). Classifier performance slightly improved (error rate = 0.29) including only women who were using continuous combined HRT treatment. According to the small amplitude of expression alterations observed after HRT use in whole blood, large sample sizes are needed to identify significant single genes differentially expressed. However, significant enrichments in biologic process of genes with small changes after HRT use were observed (e.g. receptor and transporter activities, immune response, frizzled signalling pathway, actin filament organization, glycogen metabolism). Experiment Overall Design: Indirect design with Stratagene reference Experiment Overall Design: 47 non HRT users and 42 HRT users Experiment Overall Design: No technical replicates
Project description:The American Women’s Health Initiative study published in July 2002 caused considerable concern among hormone replacement therapy (HRT) users and prescribers in many countries. This study is an exploratory research comparing the genome wide expression profile in whole blood samples according to HRT use. Within the Norwegian Women and Cancer study, 100 postmenopausal women (50 HRT users and 50 non-HRT users) born between 1943 and 1949 with normal to high body mass index and no other medication use were selected. After total RNA extraction, amplification and labelling, the samples were hybridized together with a common reference (Universal human reference RNA, Stratagen) to Agilent Human 1A oligoarrays (G4110b, Agilent Technologies, Palo Alto, CA) containing 20,173 unique genes. Differentially expressed genes were used to build a classifier using the nearest shrunken centroids method (PAM). Then, we tested the significant changes in single genes by different methods like t-test, Significance Analysis of Microarrays (SAM) and Bayesian ANOVA analysis (BAM). Results did not reveal any distinct gene list which predicted accurately HRT exposure (error rate = 0.45). Classifier performance slightly improved (error rate = 0.29) including only women who were using continuous combined HRT treatment. According to the small amplitude of expression alterations observed after HRT use in whole blood, large sample sizes are needed to identify significant single genes differentially expressed. However, significant enrichments in biologic process of genes with small changes after HRT use were observed (e.g. receptor and transporter activities, immune response, frizzled signalling pathway, actin filament organization, glycogen metabolism). Keywords: gene expression profile and exposure
Project description:<p>21-hydroxylase deficiency (21-OHD) is an inherited disorder that results from a mutation on the CYP21A2 gene. It affects the adrenal glands and is the most common cause of congenital adrenal hyperplasia (CAH). 21-OHD CAH causes the body to produce an insufficient amount of cortisol and an excess of androgen, the type of hormone that produces male characteristics. The primary treatment for 21-OHD CAH, glucocorticoid replacement therapy, has been shown to cause bone loss. However, the elevated hormone levels caused by 21-OHD CAH may increase production of the protein osteoprotegerin (OPG), which in turn may protect against bone loss. This study will compare bone density and OPG levels in women who have 21-OHD CAH and have undergone a lifetime of glucocorticoid replacement therapy to that in women who have neither of these criteria. In doing so, the study will aim to determine the relationship between OPG and bone loss.</p> <p>Because of the excess of androgen caused by 21-OHD CAH, women with CAH may exhibit some male-like characteristics. Glucocorticoids are a member of a class of drugs called corticosteroids, which are used in hormone replacement therapy. In order to counteract the effects of 21-OHD CAH, women with the disease are given hormone replacement therapy with glucocorticoids beginning at infancy. Glucocorticoids are known to cause bone loss. Despite many years of treatment with glucocorticoids, however, young women with 21-OHD CAH seem to be protected against bone loss. Researchers believe that the increased androgen levels in these women lead to increased estrogen levels, which in turn increase OPG production. The increase in OPG levels may protect women against bone loss. This study will evaluate bone density and OPG levels in women with and without 21-OHD CAH to determine the relationship between OPG and bone loss.</p> <p>Participants in this observational study will attend only one study visit. At this visit, they will undergo a blood draw; a scan of their lower spine, hip, and forearm; height and weight measurements; and a body fat analysis test. This last test will entail a weak and painless electrical signal being sent from foot to foot. Participants will not attend any follow-up visits for this study.</p>
Project description:This study investigated differences in serum exosome microRNA-cargo, obtained from healthy postmenopausal monozygotic twins (n=10 pairs), from which the other sister was using estrogen-based hormone replacement therapy (HRT) and the other was not under treatment. In addition, premenopausal women (n=8) with natural hormonal status were included in the study. This study gave new information about the exomiR messaging and its sensitivity to age and HRT.
Project description:Postmenopausal hormone therapy (HT) is associated with many diseases and conditions, but the underlying molecular mechanisms involved are incompletely understood. The aim of the current study was to investigate the effect of 4 types of HT on gene transcription. 24 women (6 women in 4 treatment groups) received 2 mg 17M-NM-2-estradiol combined with 1 mg noresthisterone acetate (NETA), 1 mg 17M-NM-2-estradiol combined with 0.5 mg NETA, tibolone, or raloxifene hydrochloride. RNA was isolated from whole blood before treatment (baseline) and after 6 weeks on treatment. The changes in mRNA from baseline to 6 weeks were assessed with a microarray chip. 4 treatment groups with 6 women in each group were blood sampled before treatment (baseline) and after 6 weeks on treatment, that is a total of 48 samples. The gene expression data at 6 weeks were compared to the expression data at baseline for each treatment.
Project description:Using a large representative sample of postmenopausal women in the Norwegian Women and Cancer (NOWAC) postgenome study, we investigated blood gene expression changes due to intra-technical variability, normal inter-individuality (age, body mass index, fasting status), and exposure variables (smoking, hormone therapy and medication use) at proportion and level of real life situation revealing mechanistic insights of these effects mirrored in blood.
Project description:Whole blood rather than purified peripheral blood mononuclear cells is likely to become the prime tissue using expression microarrays for disease predication or prognosis however excess of globin mRNA may reduce probe detection sensitivity. In our study, we assessed whether whole-blood or globin-reduced RNA gives the most robust and sensitive results to detect small gene expression changes in response to hormone replacement therapy exposure. Each sample (N = 12) were hybridized according to 3 different protocols: no globin reduction (controls), globin reduction using peptid nucleic acids (PNA) and using magnetic beads in the GlobinClear kit from Ambion. Finally, 7 and 4 technical replicates were conducted in no globin reduction and PNA groups, respectively. Both globin reduction approaches were mostly efficient at reducing globin RNA from cRNA. Samples processed by GlobinClear kit gave a very distinct gene expression profiles from the controls while samples processed with PNA gave an intermediary profile closest to the non globin reduction group with a slight increased sensitivity of transcript detection but a loss of reproducibility. Overall, no sign of higher sensitivity in detection of gene expression changes followed by hormone exposure was observed after globin reduction which was therefore judged not beneficial. Keywords: Groups comparaison