Monocytes and pyrophosphate promote mesenchymal stem cell viability and early osteogenic differentiation

Pyrophosphate-containing calcium phosphate implants promote osteoinduction and bone regeneration. The role of pyrophosphate for inflammatory cell-mesenchymal stem cell (MSC) cross-talk during osteogenesis is not known. In the present work, the effects of lipopolysaccharide (LPS) and pyrophosphate (PPi) on primary human monocytes and on osteogenic gene expression in human adipose-derived MSCs were evaluated in vitro, using conditioned media transfer as well as direct effect systems. Direct exposure to pyrophosphate increased nonadherent monocyte survival (by 120% without LPS and 235% with LPS) and MSC viability (LDH) (by 16-19% with and without LPS). Conditioned media from LPS-primed monocytes significantly upregulated osteogenic genes (ALP and RUNX2) and downregulated adipogenic (PPAR-γ) and chondrogenic (SOX9) genes in recipient MSCs. Moreover, the inclusion of PPi (250 μM) resulted in a 1.2- to 2-fold significant downregulation of SOX9 in the recipient MSCs, irrespective of LPS stimulation or culture media type. These results indicate that conditioned media from LPS-stimulated inflammatory monocytes potentiates the early MSCs commitment towards the osteogenic lineage and that direct pyrophosphate exposure to MSCs can promote their viability and reduce their chondrogenic gene expression. These results are the first to show that pyrophosphate can act as a survival factor for both human MSCs and primary monocytes and can influence the early MSC gene expression. Graphical abstract.

What you say and what I hear-Investigating differences in the perception of the severity of psychological and physical violence in intimate partner relationships

The correct communication of the severity of violence is essential in the context of legal trials, custody cases, support of victims, etc., for providing fair treatment. A narrator that communicates their experiences of interpersonal violence may rate the seriousness of the incident differently than a rater reading the narrator's text, suggesting that there exist perceptual differences (PD) in severity ratings between the narrator and the rater. We propose that these perceptual differences may depend on whether the narrative is based on physical or psychological violence, and on gender differences. Physical violence may be evaluated as more serious by the receiver of the narrative than by the narrator (Calibration PD), whereas the seriousness of psychological violence may be difficult to convey, leading to a discrepancy in the seriousness ratings between the narrator and the rater (Accuracy PD). In addition, gender stereotypes may influence the seriousness rating (Gender PD), resulting in violence against women being perceived as more serious than the same violence against men. These perceptual differences were investigated in 3 phases using a new experimental procedure. In Phase 1, 113 narrators provided descriptions and seriousness ratings of self-experienced physical and psychological violence in relationships. In Phase 2, 340 independent raters rated the seriousness of 10 randomly selected narrations from Phase 1. In Phase 3, the genders in the narrations were changed to the opposite gender, and seriousness ratings were collected from 340 different raters. Our results confirmed the hypothesized perceptual differences. Violence to male victims was considerably more likely to be seen as severe when the raters were misled to believe the victim was a woman. We propose that these data provide practical guidelines for how to deal with misinformation in the communication of violence. The data also show that mean values and the confidence of such severity ratings need to be adjusted for several factors, such as whether it is self-experienced or communicated, the type of violence, and the gender of the victims and raters.