(312) The Effect of Fetal Sex and Maternal Race on Intraamniotic Inflection Leading to Fetal Neuroinflammation

To determine if fetal sex and maternal race influence fetal neuroinflammation in response to infectious inflammation in-utero in an organ-on-chip (OOC) model under normal or pathologic conditions utilizing amniotic fluid from male and female fetuses of White Hispanic and African-American mothers.


Study Design:

The OOC is composed of two-cell culture chambers connected by Type IV collagen-coated microchannels (Figure 1B). Male-derived human fetal astroglia (SVGp12) and microglia (HMC3) were co-cultured at an 80:20 ratio in the inner chamber (Figure 1C-D). 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; to recreate infectious inflammation environment) and incubated for 48 hours. Glial migration (brightfield microscopy), glial activation (Immunocytochemistry for high activation marker-CD11b/low resting marker-Iba1), and cytokine profiles (Multiplex) were determined (N=4 of each male-WH, male-AA, female-WH, female-AA) (Figure 1D). Student T-test determined significance (p < 0.05 or p< 0.01).


Results:

In a pooled analysis (regardless of sex and race), LPS did not induce cell migration, glial activation, or inflammatory changes compared to untreated AF. When stratified by sex, male AF induced significantly higher levels of interleukin-6 compared to female AF (p < 0.05). LPS treatment of male AF promoted significant microglia activation (high CD11b: p< 0.05 [Figure 1E-F]); low Iba1: p< 0.01) compared to untreated male AF. When stratified by race/ethnicity, LPS-treated AF induced microglia activation in both groups, but a differential increase in pro-inflammatory cytokine production was seen between WH and AA AF-treated cells (WH- interleukin-1b: p< 0.05; AA- interleukin-8: p< 0.01) (Figure 1E-F).


Conclusion:

OOC experiments have determined that sex and racial differences do exist for neuroinflammation and perinatal brain injury. In this study, male fetal sex and neonates of WH race were more susceptible to an intraamniotic inflammation leading to neuroinflammation.