Preeclampsia (PE), a pregnancy complication characterized by high blood pressure and organ damage, has been suggested to be associated with mitochondrial dysfunction, although evidence remains limited. This study aimed to investigate the activity of oxidative phosphorylation (OXPHOS) enzymes and the expression of related proteins in placental tissues from women diagnosed with early-onset preeclampsia (eoPE, <34 weeks of gestation), late-onset preeclampsia (loPE, ≥34 weeks of gestation), and normotensive controls. Placental samples were analyzed using immunohistochemistry, western blotting, and enzymatic activity assays to assess the activity and expression of OXPHOS complexes. Complex I activity was increased by 80% in eoPE and 56% in loPE, with positive correlations between normalized complex I expression, gestational age at delivery (r = 0.85, p = 0.01), and birth weight (r = 0.88, p = 0.004) in loPE. Relative complex II expression in loPE showed positive correlations with pregnancy duration (r = 0.76, p = 0.03) and birth weight (r = 0.77, p = 0.03), while in controls, complex II expression correlated with pregnancy duration (r = 0.64, p = 0.03). Additionally, complex IV enzyme activity in eoPE was negatively correlated with maternal age at birth (r = −0.69, p = 0.03). The observed correlations highlight mitochondrial metabolism as a promising biomarker for predicting disease progression and guiding therapeutic interventions in preeclampsia. Unraveling its precise role in PE pathogenesis is critical to advancing diagnostic precision and improving maternal-fetal outcomes.

Human platelet lysate (HPL) is an efficient alternative for animal serum supplements, significantly enhancing stromal cell proliferation. However, the molecular mechanism behind this growth-promoting effect remains elusive. The aim of this study was to investigate the effect of HPL on cell cycle gene expression in different human stromal cells and to identify the main key players that mediate HPL’s growth-enhancing effect. RT-qPCR and an antibody array revealed significant upregulation of cell cycle genes in stromal cells cultured in HPL. As HPL is rich in growth factors that are ligands of tyrosine kinase receptor (TKR) pathways, we used TKR inhibitors and could significantly reduce cell proliferation. Genome profiling, RT-qPCR and Western blotting revealed an enhanced expression of the transcription factors signal transducer and activator of transcription 3 (STAT3) and MYC, both known TKR downstream effectors and stimulators of cell proliferation, in response to HPL. In addition, specifically blocking STAT3 resulted in reduced cell proliferation and expression of cell cycle genes. Our data indicate that HPL-enhanced cell proliferation can, at least in part, be explained by the TKR-enhanced expression of STAT3 and MYC, which in turn induce the expression of genes being involved in the promotion and control of the cell cycle.

•The receptor tyrosine kinase (RTK) Axl and its ligand Gas6 are critically involved in the pathogenesis of high-grade glioma (HGG). Both proteins were found to be overexpressed e.g. in tumor cells, mediating cell proliferation and migration as well as tumor angiogenesis and neuroinflammation. The extracellular domain of Axl (sAxl) and Gas6 were found in the peri-tumoral edema and blood of animals as well as in human glioma tissue. Therefore, we monitored the level of sAxl and Gas6 in human blood samples. To increase the sensitivity of protein detection beyond commonly used standard methods we preliminary tested the innovative Proseek Single-Plex Protein Assay Kit System from Olink Bioscience together with new antibodies against the soluble RTK sAxl and its ligand Gas6. We conclude that the Proseek method is a highly sensitive and fast procedure that can be used as a possible powerful tool compared to routinely used ELISA-methods.