A systematic scientometric review of paternal inheritance of acquired metabolic traits

BACKGROUND

The concept of the inheritance of acquired traits, a foundational principle of Lamarck's evolutionary theory, has garnered renewed attention in recent years. Evidence for this phenomenon remained limited for decades but gained prominence with the Överkalix cohort study in 2002. This study revealed a link between cardiovascular disease incidence and the food availability experienced by individuals' grandparents during their slow growth periods, reigniting interest in the inheritance of acquired traits, particularly in the context of non-communicable diseases. This scientometric analysis and systematic review comprehensively explores the current landscape of paternally transmitted acquired metabolic traits.

RESULTS

Utilizing Scopus Advanced search and meticulous screening, we included mammalian studies that document the inheritance or modification of metabolic traits in subsequent generations of unexposed descendants. Our inclusive criteria encompass intergenerational and transgenerational studies, as well as multigenerational exposures. Predominantly, this field has been driven by a select group of researchers, potentially shaping the design and focus of existing studies. Consequently, the literature primarily comprises transgenerational rodent investigations into the effects of ancestral exposure to environmental pollutants on sperm DNA methylation. The complexity and volume of data often lead to multiple or redundant publications. This practice, while understandable, may obscure the true extent of the impact of ancestral exposures on the health of non-exposed descendants. In addition to DNA methylation, studies have illuminated the role of sperm RNAs and histone marks in paternally acquired metabolic disorders, expanding our understanding of the mechanisms underlying epigenetic inheritance.

CONCLUSIONS

This review serves as a comprehensive resource, shedding light on the current state of research in this critical area of science, and underscores the need for continued exploration to uncover the full spectrum of paternally mediated metabolic inheritance.

Metabolic drivers of dysglycemia in pregnancy: ethnic-specific GWAS of 146 metabolites and 1-sample Mendelian randomization analyses in a UK multi-ethnic birth cohort

Introduction

Gestational diabetes mellitus (GDM) is the most common pregnancy complication worldwide and is associated with short- and long-term health implications for both mother and child. Prevalence of GDM varies between ethnicities, with South Asians (SAs) experiencing up to three times the risk compared to white Europeans (WEs). Recent evidence suggests that underlying metabolic difference contribute to this disparity, but an investigation of causality is required.

Methods

To address this, we paired metabolite and genomic data to evaluate the causal effect of 146 distinct metabolic characteristics on gestational dysglycemia in SAs and WEs. First, we performed 292 GWASs to identify ethnic-specific genetic variants associated with each metabolite (P ≤ 1 x 10-5) in the Born and Bradford cohort (3688 SA and 3354 WE women). Following this, a one-sample Mendelian Randomisation (MR) approach was applied for each metabolite against fasting glucose and 2-hr post glucose at 26-28 weeks gestation. Additional GWAS and MR on 22 composite measures of metabolite classes were also conducted.

Results

This study identified 15 novel genome-wide significant (GWS) SNPs associated with tyrosine in the FOXN and SLC13A2 genes and 1 novel GWS SNP (currently in no known gene) associated with acetate in SAs. Using MR approach, 14 metabolites were found to be associated with postprandial glucose in WEs, while in SAs a distinct panel of 11 metabolites were identified. Interestingly, in WEs, cholesterols were the dominant metabolite class driving with dysglycemia, while in SAs saturated fatty acids and total fatty acids were most commonly associated with dysglycemia.

Discussion

In summary, we confirm and demonstrate the presence of ethnic-specific causal relationships between metabolites and dysglycemia in mid-pregnancy in a UK population of SA and WE pregnant women. Future work will aim to investigate their biological mechanisms on dysglycemia and translating this work towards ethnically tailored GDM prevention strategies.

Effect of dietary n-6: n-3 Poly-Unsaturated fatty acids ratio on gestational diabetes mellitus: a prospective cohort

OBJECTIVE

The aim of this study was to investigate the relationship between dietary n-6: n-3 poly-unsaturated fatty acids (PUFA) ratio and the risk of developing gestational diabetes mellitus (GDM).

MATERIALS AND METHODS

A total of 100 pregnant women were prospectively included for detailed information on dietary intake at 16-18 weeks evaluated using a three-day food record, and subsequent GDM diagnosis at 24-28 weeks. Participants were divided into two groups for analysis: GDM group (n = 22) and control group (n = 78) based on oral glucose tolerance test results performed between 24 and 28 weeks.

RESULTS

The average dietary n-6: n-3 PUFA ratio in the control group was 5.63 ± 2.12 and that in the GDM group was 8.35 ± 3.45, within a significant difference (p < .05). A significant difference was associated with a higher dietary n-6: n-3 PUFA ratio and GDM (adjusted odds ratio = 4.29, 95%confidence interval:1.303, 14.124).

CONCLUSIONS

Higher dietary n-6: n-3 PUFA ratio was associated with higher odds of GDM. Given the small sample, further studies are required to confirm this hypothesis.

Characterisation of insomnia as an environmental risk factor for asthma via Mendelian randomization and gene environment interaction

Asthma is a complex disease that is reportedly associated with insomnia. However, the causal directionality of this association is still unclear. We used asthma and insomnia-associated single nucleotide polymorphisms (SNPs) and genome-wide association study (GWAS) summary statistics to test the causal directionality between insomnia and asthma via Mendelian randomization (MR) analysis. We also performed a cross-trait meta-analysis using UK Biobank GWAS summary statistics and a gene–environment interaction study using data from UK Biobank. The interaction of genetic risk score for asthma (GRS_asthma) with insomnia on asthma was tested by logistic regression. Insomnia was a risk factor for the incidence of asthma, as revealed by three different methods of MR analysis. However, asthma did not act as a risk factor for insomnia. The cross-trait meta-analysis identified 28 genetic loci shared between asthma and insomnia. In the gene–environment interaction study, GRS_asthma interacted with insomnia to significantly affect the risk of asthma. The results of this study highlight the importance of insomnia as a risk factor of asthma, and warrant further analysis of the mechanism through which insomnia affects the risk of asthma.

Altered Indices of Fatty Acid Elongases ELOVL6, ELOVL5, and ELOVL2 Activities in Patients with Impaired Fasting Glycemia

Background: Dysregulation of fatty acids (FA) seems to participate in the pathogenesis of disorders such as metabolic syndrome (MetS), cardiovascular diseases, or some cancers. Activities of enzymes FA desaturases and elongases [elongation of very long-chain fatty acid (ELOVL)] significantly influence FA profile in different body compartments. Although the impact of activities of desaturases on cardiometabolic diseases was broadly studied, relatively little attention was devoted to the role of elongases. Methods: Case-control study was carried out in 36 patients (18 men/18 women) with impaired fasting glycemia (IFG) without MetS and 36 age and gender-matched healthy controls. FA profiles in plasma phospholipids (PL) were assessed using gas chromatograph-flame ionization detector and indices of desaturase and elongase activities were calculated. Results: In the IFG group, we observed decreased estimated activities of ELOVL2 and ELOVL5, whereas higher estimated activities of elongase ELOVL6 were noted. IFG group was also characterized by altered composition of plasma PL FA, above all by lower percentage of cis-vaccenic acid (cVA; 18:1n-7) and of total polyunsaturated FA n-6, especially linoleic acid, and by higher proportion of stearic acid and gamma-linolenic acid. Concurrently, elevated estimated activities of desaturases delta-9-desaturase (D9D), D6D were found. Conclusions: Lower estimated activities of ELOVL2 and ELOVL5 with lowered proportion of PL cVA could be associated with disturbances of glucose homeostasis development and their corresponding indices could serve as biomarkers of such risk.