Systematic investigation of imprinted gene expression and enrichment in the mouse brain explored at single-cell resolution.

BACKGROUND: Although a number of imprinted genes are known to be highly expressed in the brain, and in certain brain regions in particular, whether they are truly over-represented in the brain has never been formally tested. Using thirteen single-cell RNA sequencing datasets we systematically investigated imprinted gene over-representation at the organ, brain region, and cell-specific levels. RESULTS: We established that imprinted genes are indeed over-represented in the adult brain, and in neurons particularly compared to other brain cell-types. We then examined brain-wide datasets to test enrichment within distinct brain regions and neuron subpopulations and demonstrated over-representation of imprinted genes in the hypothalamus, ventral midbrain, pons and medulla. Finally, using datasets focusing on these regions of enrichment, we identified hypothalamic neuroendocrine populations and the monoaminergic hindbrain neurons as specific hotspots of imprinted gene expression. CONCLUSIONS: These analyses provide the first robust assessment of the neural systems on which imprinted genes converge. Moreover, the unbiased approach, with each analysis informed by the findings of the previous level, permits highly informed inferences about the functions on which imprinted gene expression converges. Our findings indicate the neuronal regulation of motivated behaviours such as feeding and sleep, alongside the regulation of pituitary function, as functional hotspots for imprinting. This adds statistical rigour to prior assumptions and provides testable predictions for novel neural and behavioural phenotypes associated with specific genes and imprinted gene networks. In turn, this work sheds further light on the potential evolutionary drivers of genomic imprinting in the brain.

Maternal care boosted by paternal imprinting in mammals.

In mammals, mothers are the primary caregiver, programmed, in part, by hormones produced during pregnancy. High-quality maternal care is essential for the survival and lifelong health of offspring. We previously showed that the paternally silenced imprinted gene pleckstrin homology-like domain family A member 2 (Phlda2) functions to negatively regulate a single lineage in the mouse placenta called the spongiotrophoblast, a major source of hormones in pregnancy. Consequently, the offspring's Phlda2 gene dosage may influence the quality of care provided by the mother. Here, we show that wild-type (WT) female mice exposed to offspring with three different doses of the maternally expressed Phlda2 gene-two active alleles, one active allele (the extant state), and loss of function-show changes in the maternal hypothalamus and hippocampus during pregnancy, regions important for maternal-care behaviour. After birth, WT dams exposed in utero to offspring with the highest Phlda2 dose exhibit decreased nursing and grooming of pups and increased focus on nest building. Conversely, 'paternalised' dams, exposed to the lowest Phlda2 dose, showed increased nurturing of their pups, increased self-directed behaviour, and a decreased focus on nest building, behaviour that was robustly maintained in the absence of genetically modified pups. This work raises the intriguing possibility that imprinting of Phlda2 contributed to increased maternal care during the evolution of mammals.

Impacts of depression subcase and case on all-cause mortality in older people: The findings from the multi-centre community-based cohort study in China.

OBJECTIVES: It is unclear whether and to what extent depression subcases and cases in older age were associated with all-cause mortality. Little is known about gender differences in the associations. We assess these in older Chinese. METHODS: We examined a random sample of 6124 participants aged ≥60 years across five provinces in China. They were interviewed using a standard method of the GMS-AGECAT to diagnose depression subcase and case and record sociodemographic and disease risk factors at baseline, and to follow up their vital status. We employed Cox regression models to determine all-cause mortality in relation to depression subcases and cases, with adjustment for important variables, including social support and co-morbidities. RESULTS: Over the 10-year follow-up, 928 deaths occurred. Compared to those without depression at baseline, participants with depression subcase (n = 196) and case (n = 264) had increased risk of mortality; adjusted hazard ratios (HRs) were 1.46 (95% CI 1.07-2.00) and 1.45 (1.10-1.91). The adjusted HRs in men were 1.15 (0.72-1.81) and 1.85 (1.22-2.81), and in women 1.87 (1.22-2.87) and 1.22 (0.83-1.77) respectively. In participants aged ≥65 years, the adjusted HRs were 1.12 (0.68-1.84) and 1.99 (1.28-3.10) in men, and 2.06 (1.32-2.24) and 1.41 (0.94-2.10) in women. Increased HR in depression subcases was higher in women than man (ratio of HRs was 1.84, p = 0.034). CONCLUSIONS: Older people with depression subcase could have increased all-cause mortality to a similar extent to those with depression case. More attention should be paid to subcases of depression in women to tackle gender inequalities and improve survival.

Risk factors for excessive gestational weight gain in a UK population: a biopsychosocial model approach.

BACKGROUND: Gestational weight gain (GWG) can have implications for the health of both mother and child. However, the contributing factors remain unclear. Despite the advantages of using a biopsychosocial approach, this approach has not been applied to study GWG in the UK. This study aimed to investigate the risk factors of excessive GWG in a UK population, employing a biopsychosocial model. METHODS: This study utilised data from the longitudinal Grown in Wales (GiW) cohort, which recruited women in late pregnancy in South Wales. Specifically, data was collected from midwife recorded notes and an extensive questionnaire completed prior to an elective caesarean section (ELCS) delivery. GWG was categorised according to Institute of Medicine (IOM) guidelines. The analysis was undertaken for 275 participants. RESULTS: In this population 56.0% of women had excessive GWG. Increased prenatal depression symptoms (Exp(B)=1.10, p=.019) and an overweight (Exp(B)=4.16, p<.001) or obese (Exp(B)=4.20, p=.010) pre-pregnancy BMI, consuming alcohol in pregnancy (Exp(B)=.37, p=.005) and an income of less than £18,000 (Exp(B)=.24, p=.043) and £25-43,000 (Exp(B)=.25, p=.002) were associated with excessive GWG. CONCLUSION: GWG is complex and influenced by a range of biopsychosocial factors, with the high prevalence of excessive weight gain in this population a cause for concern. Women in the UK may benefit from a revised approach toward GWG within the National Health Service (NHS), such as tracking weight gain throughout pregnancy. Additionally, this research provides evidence for potential targets for future interventions, and potentially at-risk populations to target, to improve GWG outcomes.

Imprinted genes influencing the quality of maternal care.

In mammals successful rearing imposes a cost on later reproductive fitness specifically on the mother creating the potential for parental conflict. Loss of function of three imprinted genes in the dam results in deficits in maternal care suggesting that, like maternal nutrients, maternal care is a resource over which the parental genomes are in conflict. The induction of maternal care is a complex, highly regulated process and it is unsurprising that many gene disruptions and environmental adversities result in maternal care deficits. However, recent compelling evidence for a more purposeful imprinting phenomenon comes from observing alterations in the mother's behaviour when expression of the imprinted genes Phlda2 and Peg3 has been manipulated solely in the offspring. This explicit demonstration that imprinted genes expressed in the offspring influence maternal behaviour lends significant weight to the hypothesis that maternal care is a resource that has been manipulated by the paternal genome.

Loss of offspring Peg3 reduces neonatal ultrasonic vocalizations and increases maternal anxiety in wild-type mothers.

Depression and anxiety are the most common mental health conditions during pregnancy and can impair the normal development of mother-infant interactions. These adversities are associated with low birth weight and increased risk of behavioural disorders in children. We recently reported reduced expression of the imprinted gene PATERNALLY EXPRESSED GENE 3 (PEG3) in placenta of human infants born to depressed mothers. Expression of Peg3 in the brain has previously been linked maternal behaviour in rodents, at least in some studies, with mutant dams neglecting their pups. However, in our human study decreased expression was in the placenta derived from the fetus. Here, we examined maternal behaviour in response to reduced expression of Peg3 in the feto-placental unit. Prenatally we found novelty reactivity was altered in wild-type females carrying litters with a null mutation in Peg3. This behavioural alteration was short-lived and there were no significant differences the transcriptomes of either the maternal hypothalamus or hippocampus at E16.5. In contrast, while maternal gross maternal care was intact postnatally, the exposed dams were significantly slower to retrieve their pups and displayed a marked increase in anxiety. We also observed a significant reduction in the isolation-induced ultrasonic vocalizations (USVs) emitted by mutant pups separated from their mothers. USVs are a form of communication known to elicit maternal care suggesting Peg3 mutant pups drive the deficit in maternal behaviour. These data support the hypothesis that reduced placental PEG3 in human pregnancies occurs as a consequence of prenatal depression but leaves scope for feto-placental Peg3 dosage, during gestation, influencing aspects of maternal behaviour.

The imprinted Phlda2 gene modulates a major endocrine compartment of the placenta to regulate placental demands for maternal resources.

Imprinted genes, which are expressed from a single parental allele in response to epigenetic marks first established in the germline, function in a myriad of processes to regulate mammalian development. Recent work suggests that imprinted genes may regulate the signalling function of the placenta by modulating the size of the endocrine compartment. Here we provide in vivo evidence that this hypothesis is well founded. Elevated expression of the imprinted Pleckstrin homology-like domain, family a, member 2 (Phlda2) gene drives a reduction of the spongiotrophoblast endocrine compartment, diminished placental glycogen and asymmetric foetal growth restriction. Using both loss-of-function and gain-in-expression mouse models, here we further show that Phlda2 exclusively modulates the spongiotrophoblast compartment of the placenta without significantly altering the composition of the trophoblast giant cell endocrine lineages that share a common progenitor with this lineage. Additionally, we show that Phlda2 loss-of-function placentae contain nearly three times more placental glycogen than non-transgenic placentae. Remarkably, relative to a fully wild type scenario, wild type placentae also accumulate excessive glycogen. While loss-of-function of Phlda2 increased both placental weight and placental glycogen, the weight of both mutant and non-transgenic fetuses was lower than that found in a fully wild type scenario indicating that excessive glycogen accumulation comes at the cost of foetal growth. This work firstly highlights a novel signalling function for the spongiotrophoblast in stimulating the global accumulation of placental glycogen. Furthermore, this work suggests that Phlda2 manipulates the placenta's demands for maternal resources, a process that must be tightly regulated by epigenetic marks to ensure optimal foetal growth.

Increased dosage of the imprinted Ascl2 gene restrains two key endocrine lineages of the mouse Placenta.

Imprinted genes are expressed primarily from one parental allele by virtue of a germ line epigenetic process. Achaete-scute complex homolog 2 (Ascl2 aka Mash2) is a maternally expressed imprinted gene that plays a key role in placental and intestinal development. Loss-of-function of Ascl2 results in an expansion of the parietal trophoblast giant cell (P-TGC) lineage, an almost complete loss of Trophoblast specific protein alpha (Tpbpa) positive cells in the ectoplacental cone and embryonic failure by E10.5. Tpbpa expression marks the progenitors of some P-TGCs, two additional trophoblast giant cell lineages (spiral artery and canal), the spongiotrophoblast and the glycogen cell lineage. Using a transgenic model, here we show that elevated expression of Ascl2 reduced the number of P-TGC cells by 40%. Elevated Ascl2 also resulted in a marked loss of the spongiotrophoblast and a substantial mislocalisation of glycogen cells into the labyrinth. In addition, Ascl2-Tg placenta contained considerably more placental glycogen than wild type. Glycogen cells are normally located within the junctional zone in close contact with spongiotrophoblast cells, before migrating through the P-TGC layer into the maternal decidua late in gestation where their stores of glycogen are released. The failure of glycogen cells to release their stores of glycogen may explain both the inappropriate accumulation of glycogen and fetal growth restriction observed late in gestation in this model. In addition, using in a genetic cross we provide evidence that Ascl2 requires the activity of a second maternally expressed imprinted gene, Pleckstrin homology-like domain, family a, member 2 (Phlda2) to limit the expansion of the spongiotrophoblast. This "belts and braces" approach demonstrates the importance of genomic imprinting in regulating the size of the placental endocrine compartment for optimal placental development and fetal growth.

Maternal prenatal depression is associated with decreased placental expression of the imprinted gene PEG3.

BACKGROUND: Maternal prenatal stress during pregnancy is associated with fetal growth restriction and adverse neurodevelopmental outcomes, which may be mediated by impaired placental function. Imprinted genes control fetal growth, placental development, adult behaviour (including maternal behaviour) and placental lactogen production. This study examined whether maternal prenatal depression was associated with aberrant placental expression of the imprinted genes paternally expressed gene 3 (PEG3), paternally expressed gene 10 (PEG10), pleckstrin homology-like domain family a member 2 (PHLDA2) and cyclin-dependent kinase inhibitor 1C (CDKN1C), and resulting impaired placental human placental lactogen (hPL) expression. METHOD: A diagnosis of depression during pregnancy was recorded from Manchester cohort participants' medical notes (n = 75). Queen Charlotte's (n = 40) and My Baby and Me study (MBAM) (n = 81) cohort participants completed the Edinburgh Postnatal Depression Scale self-rating psychometric questionnaire. Villous trophoblast tissue samples were analysed for gene expression. RESULTS: In a pilot study, diagnosed depression during pregnancy was associated with a significant reduction in placental PEG3 expression (41%, p = 0.02). In two further independent cohorts, the Queen Charlotte's and MBAM cohorts, placental PEG3 expression was also inversely associated with maternal depression scores, an association that was significant in male but not female placentas. Finally, hPL expression was significantly decreased in women with clinically diagnosed depression (44%, p < 0.05) and in those with high depression scores (31% and 21%, respectively). CONCLUSIONS: This study provides the first evidence that maternal prenatal depression is associated with changes in the placental expression of PEG3, co-incident with decreased expression of hPL. This aberrant placental gene expression could provide a possible mechanistic explanation for the co-occurrence of maternal depression, fetal growth restriction, impaired maternal behaviour and poorer offspring outcomes.

Tonsillar Syphilis: an Unusual Site of Infection Detected by Treponema pallidum PCR.

With the reemergence of syphilis, it is important that both clinical and public health practitioners recognize the various clinical manifestations of this disease (formerly known as "the great imitator") and become familiar with the newer diagnostic tests. Here we report the first case of tonsillar syphilis diagnosed by PCR.

Functional disability and death wishes in older Europeans: results from the EURODEP concerted action.

PURPOSE: Physical illness has been shown to be a risk factor for suicidal behaviour in older adults. The association between functional disability and suicidal behaviour in older adults is less clear. The aim of this study was to examine the relationship between functional disability and death wishes in late life. METHODS: Data from 11 population studies on depression in persons aged 65 and above were pooled, yielding a total of 15,890 respondents. Level of functional disability was trichotomised (no, intermediate, high). A person was considered to have death wishes if the death wish/suicidal ideation item of the EURO-D scale was endorsed. Odds ratios for death wishes associated with functional disability were calculated in a multilevel logistic regression model. RESULTS: In total, 5 % of the men and 7 % of the women reported death wishes. Both intermediate (OR 1.89, 95 % CI 1.42; 2.52) and high functional disability (OR 3.22, 95 % CI 2.34; 4.42) were associated with death wishes. No sex differences could be shown. Results remained after adding depressive symptoms to the model. CONCLUSIONS: Functional disability was independently associated with death wishes in older adults. Results can help inform clinicians who care for older persons with functional impairment.

Do Surrogate Markers of Cardiorespiratory Fitness Predict Individual Changes in VO2peak? A Randomized Controlled Trial.

The purpose of the current study was to test the hypothesis that individual response classification for surrogate markers of cardiorespiratory fitness (CRF) will agree with response classification for VO2peak. Surrogate markers of CRF were time to fatigue on treadmill test (TTF), time trial performance (3kTT), resting heart rate (RHR), submaximal heart rate (SubmaxHR), and submaximal ratings of perceived exertion (SubmaxRPE). Twenty-five participants were randomized into a high-intensity interval training (HIIT: n = 14) group or non-exercise control group (CTL: n = 11). Training consisted of four weeks of high-intensity interval training (HIIT) - 4x4 minute intervals at 90-95% HRmax 3 times per week. We observed poor agreement between response classification for VO2peak and surrogate markers (agreement < 60% for all outcomes). Although surrogate markers and VO2peak correlated at the pre- and post-intervention time points, change scores for VO2peak were not correlated with changes in surrogate markers of CRF. Interestingly, a significant relationship (r 2 = 0.36, p = 0.02) was observed when comparing improvements in estimated training performance (VO2) and change in VO2peak. Contrary to our hypothesis, we observed poor classification agreement and non-significant correlations for changes scores of VO2peak and surrogate markers of CRF. Our results suggest that individuals concerned with their VO2peak response seek direct measurements of VO2.

Including supramaximal verification reduced uncertainty in VO2peak response rate.

Many reports describe using a supramaximal verification phase-exercising at a power output higher than the highest power output recorded during an incremental cardiopulmonary test-to validate VO2max. The impact of verification phases on estimating the proportion of individuals who increased VO2peak in response to high-intensity interval training (HIIT) remains an underexplored area in the individual response literature. This analysis investigated the influence of same-day and separate-day verification phases during repeated measurements (incremental tests-INCR1 and INCR2; incremental tests + supramaximal verification phases-INCR1+ and INCR2+) of VO2peak on typical error (TE) and the proportion of individuals classified as responders (i.e., the response rate) following 4 weeks of HIIT (n = 25) or a no-exercise control period (n = 9). Incorporation of supramaximal verification consistently reduced the standard deviation of individual response, TE, and confidence interval (CI) widths. However, variances were statistically similar across all groups (p > 0.05). Response rates increased when incorporating either one (INCR1 to INCR1+; 24%-48%, p = 0.07) or two (INCR2 to INCR2+; 28%-48%, p = 0.063) supramaximal verification phases. However, response rates remained unchanged when either zero-based thresholds or smallest worthwhile difference response thresholds were used (50% and 90% CIs, all p > 0.05). Supramaximal verification phases reduced random variability in VO2peak response to HIIT. Compared with separate-day testing (INCR2 and INCR2+), the incorporation of a same-day verification (INCR1+) reduced CI widths the most. Researchers should consider using a same-day verification phase to reduce uncertainty and better estimate VO2peak response rate to HIIT.

Standard Deviation of Individual Response for VO2max Following Exercise Interventions: A Systematic Review and Meta-analysis.

BACKGROUND: Although numerous attempts to demonstrate inter-individual differences in trainability across various outcomes have been unsuccessful, the investigation of maximal oxygen consumption (VO2max) trainability warrants further study. OBJECTIVE: Our objective was to conduct the first systematic review and meta-analysis to evaluate inter-individual differences in VO2max trainability across aerobic exercise training protocols utilizing non-exercising comparator groups. METHODS: We conducted a literature search across three databases: EMBASE, PubMed and SCOPUS. The search strategy incorporated two main concepts: aerobic exercise training and VO2max. Studies were included if they used human participants, employed standardized and supervised exercise training, reported absolute or relative VO2max, included a non-exercise comparator group, reported VO2max change scores for non-exercise and exercise groups and provided the standard deviation (SD) of change for all groups. We calculated the SD of individual response (SDIR) to estimate the presence of inter-individual differences in trainability across all studies. RESULTS: The literature search generated 32,968 studies, 24 of which were included in the final analysis. Our findings indicated that (1) the majority of variation in observed change scores following an intervention is due to measurement error, (2) calculating SDIR within a single study would not yield sufficient accuracy of SDIR due to generally small sample sizes and (3) meta-analysis of SD IR 2 across studies does not provide strong evidence for a positive value. CONCLUSION: Overall, our meta-analysis demonstrated that there is not strong evidence supporting the existence of VO2max trainability across single interventions. As such, it appears unlikely that clinically relevant predictors of VO2max response will be discovered. Registration can be found online ( https://doi.org/10.17605/OSF.IO/X9VU3 ).

Imprinted genes in mouse placental development and the regulation of fetal energy stores.

Imprinted genes, which are preferentially expressed from one or other parental chromosome as a consequence of epigenetic events in the germline, are known to functionally converge on biological processes that enable in utero development in mammals. Over 100 imprinted genes have been identified in the mouse, the majority of which are both expressed and imprinted in the placenta. The purpose of this review is to provide a summary of the current knowledge regarding imprinted gene function in the mouse placenta. Few imprinted genes have been assessed with respect to their dosage-related action in the placenta. Nonetheless, current data indicate that imprinted genes converge on two key functions of the placenta, nutrient transport and placental signalling. Murine studies may provide a greater understanding of certain human pathologies, including low birth weight and the programming of metabolic diseases in the adult, and complications of pregnancy, such as pre-eclampsia and gestational diabetes, resulting from fetuses carrying abnormal imprints.

Paranoid symptoms and hallucinations among the older people in Western Europe.

OBJECTIVE: It is not clear whether the prevalence of psychosis increases with age. We studied the age-specific prevalence of psychotic symptoms in older people in Western Europe. METHODS: Older people without dementia (age 65-104 years, N = 8762) from the western part of Europe in the EURODEP concerted action took part in psychiatric examinations. RESULTS: In total, 2.4% of the men and 2.9% of the women had psychotic symptoms. Using a multilevel logistic regression model that included gender and age as a continuous variable, we found that a 5-year increase in age increased the prevalence of psychotic symptoms (odds ratio 1.2 95% confidence interval 1.06-1.3, p = 0.001). A second multilevel regression model showed that wishing to be dead, depressed mood, functional disability, not being married and cognitive impairment measured with Mini mental state examination were all associated with psychotic symptoms whereas gender was not. CONCLUSION: The prevalence of psychotic symptoms in non-demented older people increases with age, and these symptoms are associated with other psychopathology, social isolation and problems with daily living.

A United Nations General Assembly Special Session for mental, neurological, and substance use disorders: the time has come.

Mental, neurological, and substance use (MNS) disorders are leading causes of the global burden of disease and profoundly impact the social and economic well-being of individuals and communities. The majority of people affected by MNS disorders globally do not have access to evidence-based interventions and many experience discrimination and abuses of their human rights. A United Nations General Assembly Special Session (UNGASS) is needed to focus global attention on MNS disorders as a core development issue requiring commitments to improve access to care, promote human rights, and strengthen the evidence on effective prevention and treatment.

Interactions between genetic admixture, ethnic identity, APOE genotype and dementia prevalence in an admixed Cuban sample; a cross-sectional population survey and nested case-control study.

BACKGROUND: The prevalence and incidence of dementia are low in Nigeria, but high among African-Americans. In these populations there is a high frequency of the risk-conferring APOE-e4 allele, but the risk ratio is less than in Europeans. In an admixed population of older Cubans we explored the effects of ethnic identity and genetic admixture on APOE genotype, its association with dementia, and dementia prevalence. METHODS: A cross-sectional catchment area survey of 2928 residents aged 65 and over, with a nested case-control study of individual admixture. Dementia diagnosis was established using 10/66 Dementia and DSM-IV criteria. APOE genotype was determined in 2520 participants, and genetic admixture in 235 dementia cases and 349 controls. RESULTS: Mean African admixture proportions were 5.8% for 'white', 28.6% for 'mixed' and 49.6% for 'black' ethnic identities. All three groups were substantially admixed with considerable overlap. African admixture was linearly related to number of APOE-e4 alleles. One or more APOE-e4 alleles was associated with dementia in 'white' and 'black' but not 'mixed' groups but neither this, nor the interaction between APOE-e4 and African admixture (PR 0.52, 95% CI 0.13-2.08) were statistically significant. Neither ethnic identity nor African admixture was associated with dementia prevalence when assessed separately. However, considering their joint effects African versus European admixture was independently associated with a higher prevalence, and 'mixed' or 'black' identity with a lower prevalence of dementia. CONCLUSIONS: APOE genotype is strongly associated with ancestry. Larger studies are needed to confirm whether the concentration of the high-risk allele in those with African ancestry is offset by an attenuation of its effect. Counter to our hypothesis, African admixture may be associated with higher risk of dementia. Although strongly correlated, effects of admixture and ethnic identity should be distinguished when assessing genetic and environmental contributions to disease risk in mixed ancestry populations.

Imprinted genes and regulation of gene expression by epigenetic inheritance.

Six new imprinted genes have recently been identified by association with established imprinted regions, in systematic screens or by serendipity. This brings the total to seventeen imprinted genes, which display a wide variety of functions. Some imprinted genes have been shown to be both physically and mechanistically linked within domains that are under the control of an imprinting centre. Others may apparently undergo imprinting independently. Methylation is clearly required for maintenance of mono-allelic expression while chromatin structure and non-coding RNAs may also play a role.