The development of the hypothalamus-pituitary-adrenal axis during infancy may be affected by antenatal glucocorticoid therapy

Prenatal exposure to social adversity and infant cortisol in the first year of life

Exposure to social adversity has been associated with cortisol dysregulation during pregnancy and in later childhood; less is known about how prenatal exposure to social stressors affects postnatal cortisol of infants. In a secondary analysis of data from a longitudinal study, we tested whether a pregnant woman's reports of social adversity during the third trimester were associated with their infant's resting cortisol at 1, 6, and 12 months postnatal. Our hypothesis was that prenatal exposure to social adversity would be associated with elevation of infants' cortisol. Measures included prenatal survey reports of social stressors and economic hardship, and resting cortisol levels determined from infant saliva samples acquired at each postnatal timepoint. Data were analyzed using linear mixed effects models. The final sample included 189 women and their infants (46.56% assigned female sex at birth). Prenatal economic hardship was significantly associated with infant cortisol at 6 months postnatal; reports of social stressors were not significantly associated with cortisol at any time point. Factors associated with hardship, such as psychological distress or nutritional deficiencies, may alter fetal HPA axis development, resulting in elevated infant cortisol levels. Developmental changes unique to 6 months of age may explain effects at this timepoint. More work is needed to better comprehend the complex pre- and post-natal physiologic and behavioral factors that affect infant HPA axis development and function, and the modifying role of environmental exposures.

Impact of the severity of brain injury on secondary adrenal insufficiency in traumatic brain injury patients and the influence of HPA axis dysfunction on prognosis

OBJECTIVE

To investigate secondary adrenal insufficiency post varying traumatic brain injuries' and its impact on prognosis.

METHODS

120 traumatic brain injury patients were categorized into mild, moderate and severe groups based on Glasgow Coma Scale. Adrenal function was evaluated through testing.

RESULTS

Secondary adrenal insufficiency rates were 0% (mild), 22.85% (moderate) and 44.82% (severe). Hypothalamus-pituitary-adrenal axis dysfunction rates were 14.81% (mild), 42.85% (moderate) and 63.79% (severe). Differences among groups were significant (p < .05). Patients with intact hypothalamus-pituitary-adrenal axis had shorter hospital stays and higher Glasgow Coma Scale scores. Receiver operating characteristic analysis of 24-h urinary free cortisol showed an area of 0.846, with a 17.62 μg/24h cutoff, 98.32% sensitivity and 52.37% specificity. In the low-dose adrenocorticotropic hormone test, with an 18 μg/dL cutoff, the receiver operating characteristic area was 0.546, with 46.28% sensitivity and 89.39% specificity.

CONCLUSION

As traumatic brain injury severity increases, secondary adrenal insufficiency incidence rises. The low-dose adrenocorticotropic hormone test is promising for hypothalamus-pituitary-adrenal axis evaluation. Patients with hypothalamus-pituitary-adrenal dysfunction experience prolonged hospitalization and worse prognosis.

Transgenerational inheritance of adrenal steroidogenesis inhibition induced by prenatal dexamethasone exposure and its intrauterine mechanism

BACKGROUND

Adrenal gland is the synthesis and secretion organ of glucocorticoid, which is crucial to fetal development and postnatal fate. Recently, we found that prenatal dexamethasone exposure (PDE) could cause adrenal dysfunction in offspring rats, but its multigenerational genetic effects and related mechanisms have not been reported.

METHODS

The PDE rat model was established, and female filial generation 1 (F1) rats mate with wild males to produce the F2, the same way for the F3. Three generation rats were sacrificed for the related detection. SW-13 cells were used to clarify the epigenetic molecular mechanism.

RESULTS

This study confirmed that PDE could activate fetal adrenal glucocorticoid receptor (GR). The activated GR, on the one hand, up-regulated Let-7b (in human cells) to inhibit steroidogenic acute regulatory protein (StAR) expression directly; on the other hand, down-regulated CCCTC binding factor (CTCF) and up-regulated DNA methyltransferase 3a/3b (Dnmt3a/3b), resulting in H19 hypermethylation and low expression. The decreased interaction of H19 and let-7 can further inhibit adrenal steroidogenesis. Additionally, oocytes transmitted the expression change of H19/let-7c axis to the next generation rats. Due to its genetic stability, F2 generation oocytes indirectly exposed to dexamethasone also inhibited H19 expression, which could be inherited to the F3 generation.

CONCLUSIONS

This cascade effect of CTCF/H19/Let-7c ultimately resulted in the transgenerational inheritance of adrenal steroidogenesis inhibition of PDE offspring. This study deepens the understanding of the intrauterine origin of adrenal developmental toxicity, and it will provide evidence for the systematic analysis of the transgenerational inheritance effect of acquired traits induced by PDE. Video Abstract.

Exposure to antenatal corticosteroids and infant cortisol regulation

Administration of antenatal corticosteroids (AC) is the standard of care during pregnancy for women who are at risk of early delivery. Evidence indicates that AC improve survival and reduce morbidity for preterm infants. However, research suggests that infants whose mothers receive AC have an altered hypothalamic-pituitary-axis (HPA) response to stressors in early life. Results are mixed regarding the nature of these effects, with studies showing both suppressed and augmented HPA activity. In addition, research is very limited beyond the 4th month of life. The purpose of this study was to determine if AC exposure was associated with infant cortisol levels in a resting state or in response to a stressor at 1, 6 and 12 months postnatal. We also evaluated the moderating role of preterm birth in this association. 181 women and their infants participated in the study. Women were recruited during the 3rd trimester of pregnancy; at this time, they completed the Perceived Stress Scale and provided 8 salivary samples over a 2-day period for cortisol assay. They provided these data again at 6 and 12 months postnatal. At 1, 6, and 12 months postnatal, salivary samples were collected from infants to examine their cortisol levels before and after participation in a 'stressor protocol'. Data were extracted from the medical record on AC exposure, gestational age, maternal obstetric risk, and neonatal morbidity. Mixed effects multilevel regression modeling was used to examine the aims. Infants whose mothers received AC had significantly lower resting state (B = -2.47, CI: -3.691, -0.0484) and post-stressor (B = -2.51, CI: -4.283, -0.4276) cortisol levels across the first year of life than infants whose mothers did not receive AC. There was no moderating effect of preterm birth on the relationship between AC exposure and cortisol. Results indicate a state of dampened HPA activation and cortisol hypo-arousal that persists across the first year of life among infants who were exposed to corticosteroids in utero. Further research is needed to examine mechanisms responsible for any alterations that occur during development of the fetal HPA axis, including epigenetic and biochemical factors that control hormonal secretion, negative feedback, and glucocorticoid receptor function throughout the HPA axis. Findings warrant careful consideration by obstetric clinicians of the benefits and risks of prescribing AC.

Intrauterine malnutrition disrupts leptin and ghrelin milk hormones, programming rats

Herein, we assessed milk hormones, the biochemical composition of milk, and its association with neonatal body weight gain and metabolic homeostasis in weaned rats whose mothers were undernourished in the last third of pregnancy. From the 14th day of pregnancy until delivery, undernourished mothers had their food restricted by 50% (FR50), whereas control mothers were fed ad libitum. The litter size was adjusted to eight pups, and rats were weaned at 22 days old. Milk and blood from mothers, as well as blood and tissues from pups, were collected for further analyses. At birth, FR50 pups were smaller than control pups, and they exhibited hyperphagia and rapid catch-up growth during the suckling period. On day 12, the milk from FR50 mothers had higher energy content, glucose, total cholesterol, triglycerides, and acylated ghrelin but lower leptin and corticosterone levels. Interestingly, FR50 mothers were hypoglycemic and hyperleptinemic at the end of the nursing period. Weaned FR50 pups had an obese phenotype and exhibited insulin resistance, which was associated with hyperglycemia and hypertriglyceridemia; they also had high blood levels of total cholesterol, leptin, and acylated ghrelin. In addition, the protein expression of growth hormone secretagogue receptor (GHSR) in the hypothalamus was increased by almost 4-fold in FR50 pups. In summary, maternal calorie restriction during the last third of pregnancy disrupts energy and metabolic hormones in milk, induces pup hyperleptinemia and hyperghrelinemia, and upregulates their hypothalamic GHSR, thus suggesting that the hypothalamic neuroendocrine circuitry may be working to address the early onset of obesity.

Perinatal programming of metabolic diseases: The role of glucocorticoids

The worldwide increase in metabolic diseases has urged the scientific community to improve our understanding about the mechanisms underlying its cause and effects. A well supported area of studies had related maternal stress with early programming to the later metabolic diseases. Mechanisms upon origins of metabolic disturbances are not yet fully understood, even though stressful factors rising glucocorticoids have been put out as pivotal trigger by programming metabolic diseases as long-term consequence. Considering energy balance and glucose homeostasis, by producing and/or sensing regulator signals, hypothalamus-pituitary-adrenal axis and endocrine pancreas are directly affected by glucocorticoids excess. We focus on the evidences reporting the role of increased glucocorticoids due to perinatal insults on the physiological systems involved in the metabolic homeostasis and in the target organs such as endocrine pancreas, white adipose tissue and blood vessels. Besides, we review some mechanisms underlining the malprogramming of type 2 diabetes, obesity and hypertension. Studies on this field are currently ongoing and even there is a good understanding regarding the effects of glucocorticoids addressing metabolic diseases, few is known about the relationship between maternal insults rising glucocorticoids to pups' metabolic disturbances, a thorough understanding about that may provide pivotal clinical clues regarding those disorders.