Dataset Information

Effects of paternal exposure to cigarette smoke on sperm DNA methylation and long-term metabolic syndrome in offspring.

ABSTRACT:

Background

Although paternal exposure to cigarette smoke may contribute to obesity and metabolic syndrome in offspring, the underlying mechanisms remain uncertain.

Methods

In the present study, we analyzed the sperm DNA-methylation profiles in tobacco-smoking normozoospermic (SN) men, non-tobacco-smoking normozoospermic (N) men, and non-smoking oligoasthenozoospermic (OA) men. Using a mouse model, we also analyzed global methylation and differentially methylated regions (DMRs) of the DLK1 gene in paternal spermatozoa and the livers of progeny. In addition, we quantified DLK1 expression, executed an intra-peritoneal glucose tolerance test (IPGTT), measured serum metabolites, and analyzed liver lipid accumulation in the F1 offspring.

Results

Global sperm DNA-methylation levels were significantly elevated (p < 0.05) in the SN group, and the methylation patterns were different among N, SN, and OA groups. Importantly, the methylation level of the DLK1 locus (cg11193865) was significantly elevated in the SN group compared to both N and OA groups (p < 0.001). In the mouse model, the group exposed to cigarette smoke extract (CSE) exhibited a significantly higher global methylation DNA level in spermatozoa (p < 0.001) and on the DMR sites of Dlk1 in 10-week-old male offspring (p < 0.05), with a significant increase in Dlk1 expression in their livers (p < 0.001). In addition, IPGTT and LDL levels were significantly altered (p < 0.001), with elevated liver fat accumulation (p < 0.05) in F1 offspring.

Conclusion

Paternal exposure to cigarette smoke led to increased global methylation of sperm DNA and alterations to the DMR of the DLK1 gene in the F1 generation, which may be inherited parentally and may perturb long-term metabolic function.

SUBMITTER: Liu Y

PROVIDER: S-EPMC8780762 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Purpose: Paternal life experiences impact offspring health via germline, and epigenetic inheritance provides a potential mechanism. However, global reprogramming during offspring embryogenesis and gametogenesis represents the largest hurdle to conceptualize it. Yet, detailed characterization of how sperm epigenetic alterations carrying “environmental memory” can evade offspring embryonic reprogramming remains elusive. Methods: we profiled the sperm DNA methylation patterns of three consecutive generations (F0, F1 and F2) in both control and stress groups by using whole-genome bisulfite sequencing (WGBS). A total of 18 sperm samples were analyzed, including three biological replicates for each generation under each treatment. In addition, small RNA sequencing was carried out on paternal sperm samples to investigate whether long-term psychological stress affected the enrichment of certain sncRNAs and to identify whether they participated in mediating the occurrence and paternal inheritance of the stress-induced DMRs Rsults: Using an optimized data analysis workflow, we obtained approximately 800 million clean reads per sample (build mm10) with strand-specific coverage ~21×, and the data covered ~96.00% of the total 21,867,837 reference CpG dinucleotides. A total of 24,427, 7,975, and 5,173 differentially methylated regions (DMRs) between control and stress groups were found in the F0, F1, and F2 generations, respectively. Inter- and transgenerational inheritance of paternal DMRs were at frequencies approximately 11.36% and 0.48%, respectively. These DMRs related to genes with functional implications for psychological stress response, and tissue inheritance of these DMRs passed paternal disorders epigenetically to offspring. More importantly, these DMRs evaded offspring embryonic reprogramming through erasure and subsequent reestablishment, but not via un-erasure way. Nonetheless, their reestablishment proportions in the primitive streak (E7.5) stage were altered. Furthermore, sncRNA-seq revealed that stress-induced tsRNA, miRNA and rsRNA dysregulation in paternal sperm might play important roles in DMRs occurrence and paternal inheritance.