👤 Susanne Wegener

Lipoprotein(a) (Lp(a)) is a causal risk-factor for atherosclerotic cardiovascular disease including acute ischemic stroke (AIS). The underlying pathomechanisms mediating this risk are less well understood, especially in AIS caused by large artery atherosclerosis (LAA). In this observational cohort study, we evaluated the association of Lp(a) with markers of LAA, namely carotid intima media thickness (cIMT) and the presence of extra- or intracranial vessel narrowing plaques. Among participants of the BIOSIGNAL cohort study we determined Lp(a) levels within 24 h after symptom onset in 1161 AIS patients from the single center of Zurich. cIMT was determined using a semi-automated computerized edge tracking software, internal carotid artery (ICA) stenosis was graded according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, intracranial ultrasound was performed by transcranial color-coded duplex (TCCD). Higher Lp(a) levels were not associated with an increased cIMT in univariable or multivariable regression models containing known cardiovascular risk factors. Higher Lp(a) levels were not associated with the presence of neither extracranial high-grade ICA-stenosis nor significant intracranial stenosis assessed by neurovascular ultrasound. In AIS patients higher Lp(a) levels were not associated with clinical markers of atherosclerotic burden despite its association with LAA-stroke etiology and an increased risk for stroke recurrence. Date of registration: 17–10-2014. Registration-URL: http://www.clinicaltrials.gov; Unique identifier: NCT-02274727. The online version contains supplementary material available at 10.1186/s12944-026-02913-6. Show less

Embryonic developmental studies under microgravity conditions in space are very limited. To study the effects of altered gravity on the embryonic development processes we established an in vitro methodology allowing differentiation of mouse embryonic stem cells (mESCs) under simulated microgravity within a fast-rotating clinostat (clinorotation) and capture of microarray-based gene signatures. The differentiating mESCs were cultured in a 2D pipette clinostat. The microarray and bioinformatics tools were used to capture genes that are deregulated by simulated microgravity and their impact on developmental biological processes. The data analysis demonstrated that differentiation of mESCs in pipettes for 3 days resultet to early germ layer differentiation and then to the different somatic cell types after further 7 days of differentiation in the Petri dishes. Clinorotation influences differentiation as well as non-differentiation related biological processes like cytoskeleton related 19 genes were modulated. Notably, simulated microgravity deregulated genes Cyr61, Thbs1, Parva, Dhrs3, Jun, Tpm1, Fzd2 and Dll1 are involved in heart morphogenesis as an acute response on day 3. If the stem cells were further cultivated under normal gravity conditions (1 g) after clinorotation, the expression of cardiomyocytes specific genes such as Tnnt2, Rbp4, Tnni1, Csrp3, Nppb and Mybpc3 on day 10 was inhibited. This correlated well with a decreasing beating activity of the 10-days old embryoid bodies (EBs). Finally, we captured Gadd45g, Jun, Thbs1, Cyr61and Dll1 genes whose expressions were modulated by simulated microgravity and by real microgravity in various reported studies. Simulated microgravity also deregulated genes belonging to the MAP kinase and focal dhesion signal transduction pathways. One of the most prominent biological processes affected by simulated microgravity was the process of cardiomyogenesis. The most significant simulated microgravity-affected genes, signal transduction pathways, and biological processes which are relevant for mESCs differentiation have been identified and discussed below. Show less