Dietary intervention rescues maternal obesity induced behavior deficits and neuroinflammation in offspring

Abstract

Obesity induces a low-grade inflammatory state and has been associated with behavioral and cognitive alterations. Importantly, maternal environmental insults can adversely impact subsequent offspring behavior and have been linked with neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (AHDH). It is unknown if maternal obesity significantly alters offspring sociability, a key ASD feature, and if altering maternal diet will provide an efficacious intervention paradigm for behavioral deficits. Here we investigated the impact of maternal high fat diet (HFD) and maternal dietary intervention during lactation on offspring behavior and brain inflammation in mice. We found that maternal HFD increased anxiety and decreased sociability in female offspring. Additionally, female offspring from HFD-fed dams also exhibited increased brain IL-1β and TNFα and microglial activation. Importantly, maternal dietary intervention during lactation was sufficient to alleviate social deficits and brain inflammation. Maternal obesity during gestation alone was sufficient to increase hyperactivity in male offspring, a phenotype that was not ameliorated by dietary intervention. These data suggest that maternal HFD acts as a prenatal/perinatal insult that significantly impacts offspring behavior and inflammation and that dietary intervention during lactation may be an easily translatable, efficacious intervention to offset some of these manifestations.

Figure 1

High fat diet (HFD) significantly increases maternal and offspring weight. (A), Timeline for feeding schedule of HFD (60% calories from fat; black line) or control diet (CD) (10% calories from fat; white line) for the experimental conditions. (B) Percent initial weight for dams fed CD (black line, circle) or HFD (black dotted line, triangle) 6 weeks prior to and during gestation represented as mean ± SEM. N = 12 to 14 per group, *P < 0.01 (weeks 1 to 3), *P < 0.001 (week 4) or *P < 0.0001 (weeks 5 to 9), repeated measures ANOVA. (C-D) Mean weight ± SEM for male and female offspring from CD/CD, HFD/HFD, CD/HFD or HFD/CD dams at (C), P21 and (D), P32-35 (N = 7 to 22 or N = 13 to 30 per condition for males and females, respectively; one-way ANOVA with post-hoc Tukey analysis; P21 males *P = 0.0156, ****P < 0.0001; P21 females *P = 0.045, ****P < 0.0001; P32-35 males CD/CD versus HFD/HFD *P = 0.0169, CD/CD versus HFD/CD *P = 0.0319, HFD/HFD versus CD/HFD *P = 0.0113, CD/HFD versus HFD/CD *P = 0.0166; P32-35 females CD/CD versus HFD/HFD *P = 0.0189, CD/CD versus HFD/CD *P = 0.0127). Abbreviations: P, postnatal day.

Figure 2

Maternal obesity increases anxiety in female offspring with partial amelioration by diet intervention. Male and female offspring from dams fed control diet (CD) or high fat diet (HFD) throughout gestation and lactation or that underwent diet switch at lactation were examined at P32-35 in Open Field Assay (OFA). (A) Mean ± SEM for distance traveled (one-way ANOVA with post-hoc Fisher’s LSD analysis, male CD/CD versus HFD/HFD **P = 0.0054, CD/CD versus HFD/CD *P = 0.0339). No significant differences were found in female offspring for total distance. (B) Center:total distance ratios for male and female offspring shown as mean ± SEM (one-way ANOVA with post-hoc Fisher’s LSD analysis, female CD/CD versus HFD/HFD *P = 0.0415, CD/CD versus HFD/CD *P = 0.0362). (C) Number of times reared during OFA shown as mean ± SEM number for male and female offspring (one-way ANOVA with post-hoc Fisher’s LSD analysis, male CD/CD versus HFD/HFD *P = 0.0386, HFD/HFD versus CD/HFD *P = 0.0134; female CD/CD versus HFD/HFD **P = 0.0025, HFD/HFD versus CD/HFD **P = 0.003, HFD/HFD versus HFD/CD **P = 0.005). N = 7 to 22 or N = 13 to 30 per condition for males and females, respectively, as indicated in the graph. Abbreviations: P, postnatal day.

Figure 3

Maternal high fat diet (HFD) intervention at lactation prevents social abnormalities induced in female offspring by prenatal/postnatal maternal HFD. Offspring from dams fed HFD or control diet (CD) during gestation and or lactation were examined at approximately P38-42 in the 3-chamber social assay for sociability. (A) Mean ± SEM time spent in mouse cup area − time spent in empty cup area for male and females as a measure of social interest (one-way ANOVA with post-hoc Fisher’s LSD analysis, *P = 0.029). (B) Interaction scores for sociability expressed as mean ± SEM (one-way ANOVA with post-hoc Fisher’s LSD analysis, *P = 0.0423). N = 7 to 22 or N = 13 to 30 per condition for males and females, respectively, as indicated in the graph. Abbreviations: P, postnatal day.

Figure 4

Increased microglial reactivity induced by maternal obesity is ameliorated by dietary switch during lactation. (A) Brain microglial Iba1 mRNA levels from male or female offspring of CD/CD, HFD/HFD, CD/HFD and HFD/CD dams were examined at six weeks of age by quantitative RT-PCR with values depicted as mean ± SEM. N = 4 to 7 for males, N = 5 to 12 per condition for females as indicated in the graph (one-way ANOVA with post-hoc Tukey analysis, CD/CD versus HFD/HFD *P = 0.019, HFD/HFD versus HFD/CD *P = 0.0187. (B-D) Immunohistochemistry for microglial Iba1 reactivity was conducted on 50-μm amygdala brain sections. (B) Iba1 protein was analyzed by densitometry in males and females (N = 3 to 4 per condition as indicated in bars; one-way ANOVA with post-hoc Tukey analysis, female CD/CD versus HFD/HFD *P = 0.0394, HFD/HFD versus HFD/CD *P = 0.0119). Representative Iba1 staining from (C) male and (D) female offspring. Scale bars = 25 μm. Abbreviations: CD, control diet; HFD, high fat diet; P, postnatal day.

Figure 5

Maternal dietary intervention reduces pro-inflammatory cytokines in the central nervous system (CNS) of offspring from maternally obese dams. (A) IL-1β and (B) TNFα protein levels in brains from male or female offspring were examined at six weeks of age by ELISA. Values are depicted as mean ± SEM with N = 4 to 7 for males and N = 5 to 12 per condition for females as indicated in the graph. One-way ANOVA with post-hoc Tukey analysis, female IL-1β CD/CD versus HFD/HFD *P = 0.0385; female TNFα CD/CD versus HFD/HFD *P = 0.0106, HFD/HFD versus CD/HFD *P = 0.0182, HFD/HFD versus HFD/CD **P = 0.0008. No significant differences were found in male offspring. Abbreviations: CD, control diet; HFD, high fat diet; P, postnatal day.