Unraveling the Meaning of Telomeres for Child Psychiatry

Shaping long-term primate development: Telomere length trajectory as an indicator of early maternal maltreatment and predictor of future physiologic regulation

The molecular, neurobiological, and physical health impacts of child maltreatment are well established, yet mechanistic pathways remain inadequately defined. Telomere length (TL) decline is an emerging molecular indicator of stress exposure with definitive links to negative health outcomes in maltreated individuals. The multiple confounders endemic to human maltreatment research impede the identification of causal pathways. This study leverages a unique randomized, cross-foster, study design in a naturalistic translational nonhuman primate model of infant maltreatment. At birth, newborn macaques were randomly assigned to either a maltreating or a competent control mother, balancing for sex, biological mother parenting history, and social rank. Offspring TL was measured longitudinally across the first 6 months of life (infancy) from peripheral blood. Hair cortisol accumulation was also determined at 6, 12, and 18 months of age. TL decline was greater in animals randomized to maltreatment, but also interacted with biological mother group. Shorter TL at 6 months was associated with higher mean cortisol levels through 18 months (juvenile period) when controlling for relevant covariates. These results suggest that even under the equivalent social, nutritional, and environmental conditions feasible in naturalistic translational nonhuman primate models, early adverse caregiving results in lasting molecular scars that foreshadow elevated health risk and physiologic dysregulation.

FEATURES OF STOMATOLOGIC STATUS, TELOMERE LENGTHS AND PHENOTYPE OF IMMUNOCOMPETENT CELLS OF PERIPHERAL BLOOD IN CHILDREN – RESIDENTS OF UKRAINIAN TERRITORIES, CONTAMINATED WITH RADIONUCLIDES

Objective of research. To analyze features of stomatological status indexes, relative length of telomeres and phenotype of immunocompetent cells of peripheral blood in children with chronological enamel hypoplasia – residents of Ukrainian territories, contaminated with radionuclides after the Chornobyl NPP accident. Materials and methods. The object of research is chronological enamel hypoplasia (CEH) of permanent teeth, and lymphocytes of peripheral blood (PB). The subject of research is the state of oral cavity hygiene, caries intensity, gingivitis severity degree, relative telomere length (RTL), and phenotype of immunocompetent cells (ICC) of peripheral blood (PB). Methods of the research: stomatological, immunological (flow cytofluorometry), molecular genetic (fluorescence in situ hybridization-flow cytometry – flow-FISH), statistical. Results. Two types of the analysis of the stomatologic status, RTL and phenotype of PB ICC were carried out: the first is the comparison of indexes of the combined group of children with anamnesis complicated by radiation (group No. 1 with CEH + group No. 2 without CEH) comparing with the control group No. 3; the second is the analysis of indeces of the group No. 1 comparing with the same markers in children of the groups No. 2 and No. 3. The first stage of the analysis shows thesignificant worsening of oral hygien indices , high DMFTand DMFS in children with permanent dentition, higher degree of gums inflamation and moresignificant RTL shortening in children of the combined group (No. 1 + No. 2) comparing with the control. Changes of the same character, but more expressed observed during the another analysis concerning the children with anamnesis complicated by radiation and CEH comparing with the control. Reliable changes in the content of PB ICC subpopulations in the examined children of all groups were not identified. Conclusions. 1. Inchildren with CEH, complicated by ionizing radiation (IR) influence in low doses diapason the highest degree of stomatological status disorders comparing with the examined reference and control groups was determined: unsatisfactory and poor oral cavity hygiene according to OHI-S (1.76±0.41, р˂0.0001 and р˂0.0001, respectively) and Silness-Loe index (1.73±0.45, р˂0.0001 and р˂0.0001, respectively); very high intensity of dental caries ((DMFT=7.0±2.29, р=0.003and р˂0.0001; DMFS=8.74±2.58, р=0.0004 and р˂0.0001, respectively); mean degree of gingivitis severity (РМА 47.55±14.27 %, р˂0.0001 and р˂0.0001, respectively). 2. At CEH, which occurs due to the complex of negative factors during first years of life, including IR in residents of territories with effective doses more than 1.0 mSv/year, reliable shortening of relative telomeres length of PB lymphocytes comparing with the control group (15.17±3.20, р=0.0002) was found. Reliable differences in the content of peripheral blood immunocompetent cells when compared the examined groups were not identified. 3. Results of indices of the groups No. 1, No. 2 and No. 3 comparison are agreed with the data, obtained in result of dispersive analysis that allowed to separate the most informative indices concerning stomatological examination of children: OHI-S index (F=34.92; р˂0.001); Silness-Loe index (F=27.01; р˂0.001); dft+DMFT (F=82.23; р˂0.001); dfs+DMFS (F=49.41; р˂0.001); DMFT (F=13.94; р˂0.001); DMFS(F=19.41; р˂0.001); РМА (F=41.25; р˂0.001); RTL (F=7.53; р=0.001).

History of child maltreatment and telomere length in immune cell subsets: Associations with stress- and attachment-related hormones

Experiencing maltreatment during childhood can have long-lasting consequences for both mental and physical health. Immune cell telomere length (TL) shortening might be one link between child maltreatment (CM) experiences and adverse health outcomes later in life. While the stress hormone cortisol has been associated with TL attrition, the attachment-related hormone oxytocin may promote resilience. In 15 mothers with and 15 age- and body mass index-matched mothers without CM, we assessed TL in peripheral blood mononuclear cells and selected immune cell subsets (monocytes, naive, and memory cytotoxic T cells) by quantitative fluorescence in situ hybridization, as well as peripheral cortisol and oxytocin levels. Memory cytotoxic T cells showed significantly shorter TL in association with CM, whereas TL in monocytes and naive cytotoxic T cells did not significantly differ between the two groups. Across both groups, cortisol was negatively associated with TL, while oxytocin was positively associated with TL in memory cytotoxic T cells. These results indicate that long-lived memory cytotoxic T cells are most affected by the increased biological stress state associated with CM. Keeping in mind the correlational and preliminary nature of the results, the data suggest that cortisol may have a damaging and oxytocin a protective function on TL.

Accelerated telomere shortening: Tracking the lasting impact of early institutional care at the cellular level

Studies examining the association between early adversity and longitudinal changes in telomere length within the same individual are rare, yet are likely to provide novel insight into the subsequent lasting effects of negative early experiences. We sought to examine the association between institutional care history and telomere shortening longitudinally across middle childhood and into adolescence. Buccal DNA was collected 2-4 times, between the ages of 6 and 15 years, in 79 children enrolled in the Bucharest Early Intervention Project (BEIP), a longitudinal study exploring the impact of early institutional rearing on child health and development. Children with a history of early institutional care (n=50) demonstrated significantly greater telomere shortening across middle childhood and adolescence compared to never institutionalized children (n=29). Among children with a history of institutional care, randomization to high quality foster care was not associated with differential telomere attrition across development. Cross-sectional analysis of children randomized to the care as usual group indicated shorter telomere length was associated with greater percent of the child's life spent in institutional care up to age 8. These results suggest that early adverse care from severe psychosocial deprivation may be embedded at the molecular genetic level through accelerated telomere shortening.