Adapting an organ-on-chip device to study the effect of fetal sex and maternal race/ethnicity on preterm birth related intraamniotic inflammation leading to fetal neuroinflammation.

Abstract

Fetal neuroinflammation has been linked to preterm birth-related intraamniotic infection and inflammation; However, the contribution of fetal sex and maternal race/ethnicity is unknown. To determine if fetal sex and maternal race/ethnicity influence neuroinflammation, an organ-on-chip (OOC) model were established under normal or pathologic conditions utilizing amniotic fluid. OOC is composed of two-cell culture chambers connected by Type IV collagen-coated microchannels. Human fetal astroglia (SVGp12) and microglia (HMC3) were co-cultured at an 80:20 ratio in the inner chamber. The outer chamber contained amniotic fluid (AF) from male and female fetuses of White Hispanic (WH) and African-American (AA) pregnant women with or without lipopolysaccharide (LPS-100ng/ml) and incubated for 48h. Glial migration (brightfield microscopy), activation (Immunocytochemistry), and cytokine production (Luminex assays) were quantified and compared (N=4 for each category of sex and race/ethnicity). In a pooled analysis, AF+LPS did not induce glial activation or inflammatory changes compared to AF alone. When stratified by sex, male AF+LPS promoted significant glial activation (high CD11b:p<0.05; low Iba1:p<0.01) compared to male AF without LPS; however, this was not associated with changes in pro-inflammatory cytokines. When stratified by race/ethnicity, AF+LPS induced glial activation in both groups, but a differential increase in pro-inflammatory cytokines was seen between WH and AA AF (WH-interleukin-1β: p<0.05; AA-interleukin-8: p<0.01). This OOC model of fetal neuroinflammation has determined that race/ethnicity differences do exist for perinatal brain injury. The fetal sex of neonates was not a determining factor of susceptibility to intraamniotic inflammation leading to neuroinflammation.