Developmental plasticity: Friend or foe?

MicroRNA expression profiling in the adult offspring of rats with periodontal disease

OBJECTIVE

The present study investigated the relationship between maternal periodontal disease, insulin resistance, activation of inflammatory pathways and epigenetic modifications in adult offspring.

DESIGN

Therefore, female Wistar rats were divided into control and experimental groups. Seven days after the induction of periodontal disease, female rats from both groups were mated with healthy male rats. After weaning, male offspring were divided into control offspring (CN-o) and periodontal disease offspring (PED-o) groups. Body weight was measured at 0-75 days of age. At day 75, the following were measured in the offspring: insulin resistance by the HOMA-IR index; global miRNAs by microtranscriptome array; validation of the selected miRNAs by quantitative real-time PCR expression; interleukin 1 receptor associated kinase 1 (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6) content in the gastrocnemius muscle tissue (GSM) by western blotting.

RESULTS

Maternal periodontal disease leads to low birth weight (LBW) in the offspring and insulin resistance in adulthood; changes in global miRNA expression (5 miRNAs upregulated and 6 downregulated); and increased protein expression of IRAK1 and TRAF6 in GSM.

CONCLUSIONS

These findings demonstrate that maternal periodontal disease causes LBW, insulin resistance, activation of inflammatory pathways, and changes in global miRNA expression.

Maternal Mineral Nutrition Regulates Fetal Genomic Programming in Cattle: A Review

Maternal mineral nutrition during the critical phases of fetal development may leave lifetime impacts on the productivity of an individual. Most research within the developmental origins of the health and disease (DOHaD) field is focused on the role of macronutrients in the genome function and programming of the developing fetus. On the other hand, there is a paucity of knowledge about the role of micronutrients and, specifically, minerals in regulating the epigenome of livestock species, especially cattle. Therefore, this review will address the effects of the maternal dietary mineral supply on the fetal developmental programming from the embryonic to the postnatal phases in cattle. To this end, we will draw a parallel between findings from our cattle model research with data from model animals, cell lines, and other livestock species. The coordinated role and function of different mineral elements in feto-maternal genomic regulation underlies the establishment of pregnancy and organogenesis and, ultimately, affects the development and functioning of metabolically important tissues, such as the fetal liver, skeletal muscle, and, importantly, the placenta. Through this review, we will delineate the key regulatory pathways involved in fetal programming based on the dietary maternal mineral supply and its crosstalk with epigenomic regulation in cattle.

Preterm Birth, Developmental Smoke/Nicotine Exposure, and Life-Long Pulmonary Sequelae

This review delineates the main pulmonary issues related to preterm birth, perinatal tobacco/nicotine exposure, and its effects on offspring, focusing on respiratory health and its possible transmission to subsequent generations. We review the extent of the problem of preterm birth, prematurity-related pulmonary effects, and the associated increased risk of asthma later in life. We then review the impact of developmental tobacco/nicotine exposure on offspring asthma and the significance of transgenerational pulmonary effects following perinatal tobacco/nicotine exposure, possibly via its effects on germline epigenetics.

Human Gut Microbiota Plasticity throughout the Life Course

The role of the gut microbiota in human health and disease has garnered heightened attention over the past decade. A thorough understanding of microbial variation over the life course and possible ways to influence and optimize the microbial pattern is essential to capitalize on the microbiota's potential to influence human health. Here, we review our current understanding of the concept of plasticity of the human gut microbiota throughout the life course. Characterization of the plasticity of the microbiota has emerged through recent research and suggests that the plasticity in the microbiota signature is largest at birth when the microbial colonization of the gut is initiated and mode of birth imprints its mark, then decreases postnatally continuously and becomes less malleable and largely stabilized with advancing age. This continuing loss of plasticity has important implication for the impact of the exposome on the microbiota and health throughout the life course and the identification of susceptible 'windows of opportunity' and methods for interventions.

Maternal hypoxia developmentally programs low podocyte endowment in male, but not female offspring

Fetal hypoxia is a common complication of pregnancy. We have previously reported that maternal hypoxia in late gestation in mice gives rise to male offspring with reduced nephron number, while females have normal nephron number. Male offspring later develop proteinuria and renal pathology, including glomerular pathology, whereas female offspring are unaffected. Given the central role of podocyte depletion in glomerular and renal pathology, we examined whether maternal hypoxia resulted in low podocyte endowment in offspring. Pregnant CD1 mice were allocated at embryonic day 14.5 to normoxic (21% oxygen) or hypoxic (12% oxygen) conditions. At postnatal day 21, kidneys from mice were immersion fixed, and one mid-hilar slice per kidney was immunostained with antibodies directed against p57 and synaptopodin for podocyte identification. Slices were cleared and imaged with a multiphoton microscope for podometric analysis. Male hypoxic offspring had significantly lower birth weight, nephron number, and podocyte endowment than normoxic male offspring (podocyte number; normoxic 62.86 ± 2.26 podocytes per glomerulus, hypoxic 53.38 ± 2.25; p < .01, mean ± SEM). In contrast, hypoxic female offspring had low birth weight but their nephron and podocyte endowment was the same as normoxic female offspring (podocyte number; normoxic 62.38 ± 1.86 podocytes per glomerulus, hypoxic 61.81 ± 1.80; p = .88). To the best of our knowledge, this is the first report of developmentally programmed low podocyte endowment. Given the well-known association between podocyte depletion in adulthood and glomerular pathology, we postulate that podocyte endowment may place offspring at risk of renal disease in adulthood, and explain the greater vulnerability of male offspring.

Developmental origins of endometriosis: a Swedish cohort study

BACKGROUND

Endometriosis is a chronic condition affecting women of reproductive age and is associated with multiple health burdens. Yet, findings regarding its 'developmental origins' are inconsistent. We aimed to investigate the associations of birth characteristics with endometriosis. We also explored potential mediation by adult social and reproductive factors.

METHODS

This cohort study consisted of 3406 women born in Uppsala, Sweden, between 1933 and 1972. We used data from archived birth records and endometriosis diagnoses at ages 15-50 recorded in the national patient registers. Socioeconomic and reproductive characteristics were obtained from routine registers. HRs were estimated from Cox regression.

RESULTS

During the follow-up, 111 women have been diagnosed with endometriosis, and most cases are external endometriosis (ie, outside the uterus, n=91). Lower standardised birth weight for gestational age was associated with increased rate of endometriosis (HR 1.35 per standard deviation decrease; 95% CI 1.08 to 1.67). This increased rate was also detected among women with fewer number of live births (HR 2.38; 95% CI 1.40 to 4.07 for one child vs ≥2 children; HR 6.09; 95% CI 3.88 to 9.57 for no child vs ≥2 children) and diagnosed infertility problem (HR 2.00; 95% CI 1.10 to 3.61) prior to endometriosis diagnosis. All the observed associations were stronger for external endometriosis. However, no evidence was found that number of births was the mediator of the inverse association between standardised birth weight and endometriosis.

CONCLUSION

This study supports the developmental origins theory and suggests that exposure to growth restriction during the fetal period is associated with increased risk of endometriosis during reproductive years.