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Biomedical subjects

Hannele Laivuori

Publications and source records attributed to Hannele Laivuori.

8 recordsLinked to original sources

Genomic analyses implicate hormonal and metabolic dysregulation in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) and its underlying features remain poorly understood. In this genetic study (n = 544,513), we expand the number of genetic loci from 16 to 29, and additionally identify 31 associated plasma proteins. Many risk-increasing loci were associated with later age at menopause, underscoring the reproductive longevity related to an increased oocyte number and/or availability across the lifespan. Hormonal regulation in the etiology of this condition, through metabolic and reproductive features, was emphasized. The proteomic analysis highlighted metabolic biology known to be related to PCOS. A polygenic risk score (PRS) was associated with adverse cardiometabolic outcomes, with differing relevance of testosterone and body mass index in women and men. Finally, while oligo-anovulation and anovulatory infertility are features of PCOS, we observed no impact of PCOS susceptibility on childlessness. We suggest that PCOS susceptibility confers balanced pleiotropic influences on fertility in women, and life-long adverse metabolic consequences in both sexes.

Humans↗

Role of oxysterol 4β-hydroxycholesterol and liver X receptor alleles in pre-eclampsia.

BACKGROUND: Liver X receptors (LXRs) are expressed in placenta and may be associated with pre-eclampsia (PE). Oxysterols act as agonists for LXRs. We recently proposed a new blood pressure-regulating circuit with oxysterol 4β-hydroxycholesterol (4βHC) acting as a hypotensive factor via LXRs. MATERIALS AND METHODS: This study investigated the association between maternal plasma 4βHC, blood pressure (BP) indices, placental expression of LXR target genes, and patient characteristics using data from the Finnish Genetics of Pre-Eclampsia Consortium (FINNPEC) cohort. Plasma samples of 144 women with PE and 38 healthy pregnant controls as well as 44 PE and 40 control placental samples were available. In addition, genetic data from the FinnGen project was utilized to explore the associations of LXR alleles with PE and pregnancy hypertension. RESULTS: There were no significant associations between 4βHC and BP or maternal and perinatal characteristics in FINNPEC cohort. However, plasma 4βHC was inversely correlated with the maternal body mass index. There were no associations with the genetic variants of LXRs with PE in FinnGen. LXR target genes APOD, SCARB1, TGM2, and LPCAT3 were expressed differently between PE and normal pregnancies in placental samples of FINNPEC. CONCLUSIONS: Our results demonstrate that plasma 4βHC and genetic LXR variants do not play a major role in PE and BP regulation during pregnancy. However, key LXR target genes involved in lipid metabolism were expressed differently in normal and PE pregnancies. Further research is needed to understand the complexities of oxysterols, LXRs, and their potential contributions to placental function and pregnancy outcomes.

Humans↗

Genetic aspects of preeclampsia.

Preeclampsia has a familial component suggesting that one or more common alleles may act as susceptibility genes. Some families may have "private" predisposing mutations. The central role of the placenta in the pathogenesis of preeclampsia implies that fetal genes contribute to the disease process. Twin studies support the role of maternal and fetal gene interaction. Candidate gene studies have not yielded consistent results. Genome-wide linkage studies provide powerful means to study disease susceptibility genes, and several loci have been mapped. Parent-of-origin effect of the STOX1 gene has been suggested on chromosome 10q22 locus in the Dutch population. Maternally inherited missense mutations in the STOX1 gene of the fetus have been shown to co-segregate with the maternal preeclamptic phenotype. Up-regulation of placental leptin expression has been found in several studies and might be of importance in the pathogenesis of preeclampsia. DNA microarray is ideal tool for screening gene expression in preeclamptic tissues, but critical attitude is needed when interpreting the results. The placental DNA and mRNA in maternal plasma hold great promise as novel biomarkers for the prediction of preeclampsia. Finding genes prediposing to preeclampsia will enhance our understanding of the disease mechanism, and might allow identification of prognostic and therapeutic subgroups.

Chromosome Aberrations↗

Heterogeneity-based genome search meta-analysis for preeclampsia.

Preeclampsia is a pregnancy-related disorder that causes maternal and fetal morbidity and mortality. Its exact inheritance pattern is still unknown, and genome searches for identifying susceptibility loci for preeclampsia have thus far produced inconclusive or inconsistent results. We performed a heterogeneity-based genome search meta-analysis (HEGESMA) that synthesized the available genome scan data on preeclampsia. HEGESMA identifies genetic regions (bins) that rank highly on average in terms of linkage statistics across genome scans (searches). The significance of each bin's average rank and heterogeneity across scans was calculated using Monte Carlo tests. The meta-analysis involved four genome-scans on general preeclampsia and five scans on severe preeclampsia. In general preeclampsia, 13 bins had significantly high average rank (Prank< 0.05) by either unweighted or weighted analyses, while four of them (2p11.2-2q21.1, 9q21.32-9q31.2, 2p15-2p11.2, 2q32.1-2q35) were formally significant by both analyses. Heterogeneity of bin 2.8 (2q32.1-2q35) was significantly low in both unweighted and weighted analysis (PQ< 0.01). In severe preeclampsia, 10 bins had significantly high average rank by either unweighted or weighted analyses and five of them (3q11.1-3q21.2, 2q37.1-2q37.3, 18p11.32-18p11.22, 2p15-2p11.2, 7q34-7q36.3) were significant by both analyses. Bin 2q37.1-2q37.3 showed marginal low heterogeneity in unweighted and weighted analysis (PQ= 0.06). Results should be interpreted with caution as the p values were modest. Further investigation of these regions by genotyping with additional markers and families may help to direct the identification of candidate genes for preeclampsia.

Chromosome Mapping↗

Adiponectin concentrations in maternal serum: elevated in preeclampsia but unrelated to insulin sensitivity.

OBJECTIVE: Adiponectin is an adipocyte-derived protein with profound insulin-sensitizing, anti-inflammatory, and antiatherogenic effects. Surprisingly, recent evidence suggests that adiponectin concentrations are increased during preeclampsia, which is characterized by insulin resistance. We studied whether serum adiponectin is related to insulin sensitivity in preeclamptic and normotensive pregnant women. METHODS: We measured serum adiponectin concentrations and insulin sensitivity (intravenous glucose tolerance test/minimal model) in 22 women with preeclampsia and 15 normotensive controls with similar pre-pregnancy body mass index (BMI) (range 18-29 kg/m(2)) between 29 and 39 weeks of gestation. Fourteen cases and 10 controls were also studied 6-22 weeks after delivery. No subject had gestational diabetes. RESULTS: During pregnancy, the mean adiponectin concentration in preeclamptic women was 10.3 (SD 4.2) mug/mL as compared to 7.9 (SD 2.9) microg/mL in normotensive controls (95% confidence interval [CI] for difference 0.1-5.3 microg/mL; P = .04). Adiponectin concentrations were unrelated to insulin sensitivity both in preeclamptic and normotensive subjects; insulin sensitivity was decreased in preeclampsia (P = .01). After delivery, mean adiponectin concentration was lower than during pregnancy: 7.4 (SD 3.0) microg/mL in preeclamptic subjects (P = .001) and 7.1 (SD 1.6) microg/mL in normotensive controls (P = .06) and similar in cases and controls (95% CI for difference -1.7-2.3 microg/mL, P = .7). CONCLUSIONS: Despite their reduced insulin sensitivity, preeclamptic women have higher adiponectin concentrations than normotensive pregnant women. These concentrations are unrelated to insulin sensitivity. After pregnancy, the difference in adiponectin concentrations is no longer present between the two groups. These findings are consistent with a role of adiponectin in the pathophysiology of preeclampsia.

Adiponectin↗

Risk for subsequent coronary artery disease after preeclampsia.

We studied the history of hypertensive pregnancies and conventional risk factors in 141 relatively young (<66 years) parous women with angiographically documented coronary artery disease and in age-matched controls. Our study showed that hypertension, diabetes, hypercholesterolemia, advanced age, smoking, and preeclampsia are independent risk factors for subsequent coronary artery disease.

Adult↗

Is there any link between insulin resistance and inflammation in established preeclampsia?

Both insulin resistance and inflammation may contribute to the onset of preeclampsia. They also could be interrelated. We studied the relationship between inflammatory cytokines and markers of insulin resistance. During their third trimester, 22 proteinuric preeclamptic women and 16 normotensive controls underwent intravenous glucose tolerance test (minimal model). Preeclamptic women were more insulin-resistant (P = .009), and they had higher levels of serum soluble tumor necrosis alpha receptor II (TNFalpha RII) (P = .002), triglycerides (P = .006), uric acid (P = .001), and leptin (P = .002) than did the controls. However, the study groups did not differ in serum TNFalpha, C-reactive protein (CRP), interleukin-6 (IL-6), sex hormone-binding globulin (SHBG), and high-density lipoprotein-2 (HDL(2))-cholesterol. In multiple regression analysis only SHBG (P = .01) and triglycerides (P = .0036) were associated with insulin sensitivity independently of body mass index (BMI), weight gain, HDL(2)-cholesterol, CRP, TNFalpha, and TNFalpha RII, IL-6, and leptin. We conclude that insulin resistance and the inflammatory markers studied were not associated in established preeclampsia.

Biomarkers↗

Susceptibility loci for preeclampsia on chromosomes 2p25 and 9p13 in Finnish families.

Preeclampsia is a common, pregnancy-specific disorder characterized by reduced placental perfusion, endothelial dysfunction, elevated blood pressure, and proteinuria. The pathogenesis of this heterogeneous disorder is incompletely understood, but it has a familial component, which suggests that one or more common alleles may act as susceptibility genes. We hypothesized that, in a founder population, the genetic background of preeclampsia might also show reduced heterogeneity, and we have performed a genomewide scan in 15 multiplex families recruited predominantly in the Kainuu province in central eastern Finland. We found two loci that exceeded the threshold for significant linkage: chromosome 2p25, near marker D2S168 (nonparametric linkage [NPL] score 3.77; P=.000761) at 21.70 cM, and 9p13, near marker D9S169 (NPL score 3.74; P=.000821) at 38.90 cM. In addition, there was a locus showing suggestive linkage at chromosome 4q32 between D4S413 and D4S3046 (NPL score 3.13; P=.003238) at 163.00 cM. In the present study the susceptibility locus on chromosome 2p25 is clearly different (21.70 cM) from the locus at 2p12 found in an Icelandic study (94.05 cM) and the locus at 2q23 (144.7 cM) found in an Australian/New Zealand study. The locus at 9p13 has been shown to be a candidate region for type 2 diabetes in two recently published genomewide scans from Finland and China. The regions on chromosomes 2p25 and 9p13 may harbor susceptibility genes for preeclampsia.

Chromosome Mapping↗