Soren von Otte

Follicular Fluid High Density Lipoprotein-associated Sphingosine 1-Phosphate Is a Novel Mediator of Ovarian Angiogenesis

Angiogenesis plays an important role in the development of the ovarian follicle and its subsequent transition into the corpus luteum. Accordingly, follicular fluid is a rich source of mitogenic and angiogenic factors such as basic fibroblast growth factor and vascular endothelial growth factor secreted by granulosa cells. In the present study, we show that follicular fluid deprived of basic fibroblast growth factor or vascular endothelial growth factor by means of thermal denaturation or antibody neutralization retains its capacity to stimulate endothelial proliferation and angiogenesis. Mass spectrometric analysis of chromatographic fractions stimulating endothelial growth obtained from follicular fluid revealed that the heat-stable mitogenic activity is identical with the subfraction α of high density lipoproteins purified from follicular fluid (FF-HDL). Further investigations demonstrated that sphingosine 1-phosphate (S1P), one of the lysophospholipids associated with HDL, accounts for the capacity of this lipoprotein to stimulate endothelial growth and the formation of new vessels. Activation of mitogen-activated protein kinase (p42/44ERK1/2), protein kinase C, and protein kinase Akt represent signaling pathways utilized by FF-HDL and S1P to induce endothelial proliferation and angiogenesis. We conclude that FF-HDL represents a novel mitogenic and angiogenic factor present in follicular fluid and that S1P is one of the FF-HDL lipid components accounting for this activity.

Polymorphisms of haemostasis genes as risk factors for preterm delivery

Clinical trials evaluating the potential benefit of anticoagulant treatment in pregnant women with inherited thrombophilia are based on the observation that a genetic predisposition to thrombosis is associated with frequent abortions and preterm birth. It was the aim of our study to delineate the impact of genetic polymorphisms with prothrombotic and antithrombotic effects on the occurrence of preterm birth in a large cohort of very-low-birth-weight (VLBW)-infants and their mothers. We examined the factor V Leiden and the prothrombin G20210A mutation, the factor VII 121del/ins and the factor XIII Val34Leu polymorphism in preterm very-low-birth-weight (VLBW, n=593) and term-born-infants (n=278) and their mothers (n=785). The primary outcome was preterm vs.term birth. From all polymorphisms tested, the maternal factor VII-121del/ins polymorphism (26.2 vs. 17.6 %; p=0.009) and the infants factor VII-121del/ins polymorphism (29.0 vs. 20.0 %; p=0.009) were more frequent in singleton VLBW and their mothers compared to term infants and their mothers. Furthermore, the frequency of the factor XIII-Val34Leu polymorphism was significantly lower in singleton VLBW than in term infant controls (5.1 vs. 9.6%, p=0.025). In a multivariate regression analysis, previous preterm delivery (OR=3.8, 95% CI: 1.7-8.4), the maternal carrier status of the factor-VII-121del/ins polymorphism (OR=1.7, 95% CI: 1.12-2.5, p=0.007) and the lower frequency of infants factor-XIII-Val34Leu polymorphism (OR=0.53; 95% CI: 0.29-0.96; p=0.038) were found to be independently associated with preterm delivery. InVLBW mothers with pathological CTG as cause of preterm delivery, the frequency of factor V Leiden mutation was significantly increased compared to VLBW mothers without pathological CTG (14.1 vs. 6.1%, p=0.01). The investigated haemostasis gene polymorphisms have a much lower impact on subsequent preterm delivery than known risk factors such as previous preterm birth. The reported association of the factor-VII-121del/ins polymorphism on preterm delivery and its clinical relevance needs to be further elucidated.

159C>T CD14 genotype--functional effects on innate immune responses in term neonates.

Given the susceptibility of newborns to infection and the potential harm of overwhelming proinflammatory immune responses, the impact of genetic variation in innate immune molecules is of increasing interest for risk stratification and prevention. We studied the functional relevance of the 159C>T CD14 single nucleotide polymorphism in cord blood samples of n=135 healthy term neonates by investigation of sCD14, interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha concentrations in whole-blood culture supernatants and intracellular assessment of IL-1beta, IL-6, and TNF-alpha expression by flow cytometry. The 159C>T CD14 genotype frequencies were n=42 (0.31) for homozygous CD14-159 CC, n=69 (0.51) for heterozygous CD14-159 CT, and n=24 (0.18) for homozygous CD14-159 TT. No genotype-associated differences were noted for ex vivo baseline expression of sCD14, IL-6, IL-10, and TNF-alpha. After in vitro stimulation of cord blood cultures with lipopolysaccharide, carriers of the CD14-159 T allele were determined to have higher levels of sCD14 compared with carriers of the CD14-159 C allele (p=0.04) and increased concentrations of IL-6 (p=0.009) in culture supernatants (one-way analysis of variance). The 159C>T CD14 polymorphism is associated with soluble CD14 expression and cytokine expression, which might influence the balance of pro- and anti-inflammatory immune responses in healthy term neonates. Further studies are needed to delineate whether the 159C>T CD14 genotype is a risk factor for severity of neonatal infection in the clinical setting and a potential target for prevention strategies.

Lessons learned from introducing an in-vitro maturation programme into clinical practice

The technology of in-vitro maturation (IVM) aims at maturing immature oocytes from the germinal vesicle (GV) stage to the metaphase 2 stage of the second meiotic division in vitro. Gametes are obtained by immature oocyte retrieval from small antral follicles (5-12 mm) present in polycystic ovarian syndrome patients or at the beginning of each cycle of normally menstruating woman. Maturation time in vitro takes about 28-36 h. After precise patient selection and adequate preparation, a high proportion of oocytes are able to resume meiosis in vitro. Intracytoplasmic sperm injection is the preferred method of fertilization. About 300 children have been born worldwide after IVM, and are reported to be healthy. Recent data suggests that IVM has the potential to replace standard ovarian stimulation in the near future. Nevertheless, several aspects of IVM regarding safety and efficacy remain unanswered and will have to be addressed. This paper reviews data concerning IVM in clinical practice and describesexperience from the establishment of an IVM programme that resulted in the first IVM pregnancy in Germany.