The purpose of this K22 Career Development Award is to foster the career development of Dr. J. Richard Pilsner, an interdisciplinary molecular epidemiologist. A long-term research goal is to delineate the role of epigenetics as an intermediate step in the mechanistic pathway linking maternal and paternal environmental exposures to reproductive success and subsequent offspring health and development. As a newly appointed Assistant Professor, I have been provided the necessary facilities and resources to establish a robust high- throughput laboratory for epigenetic analyses tailored for large population-based studies. The objective of this K22 application is to establish a cohort study of 250 subfertile couples seeking in vitro fertilization to examine the association between paternal phthalate exposure, sperm epigenetics, and reproductive health. To this end, I have identified specific areas where additional development will enhance my success as an independent researcher. These include: 1) endocrine disruptor compounds (EDCs);2) sperm biology and male reproductive health;3) cohort and biorepository implementation and 4) epigenetic informatics and computational biology. Phthalates, an EDC, are ubiquitous environmental contaminants that are used in plastics and personal care products. Phthalate exposure is associated with a diverse set of reproductive outcomes, including male reproductive health, birth outcomes, and offspring neurodevelopment;however, a mechanistic understanding of these associations has not been clearly elucidated. Epigenetic reprogramming is essential for sperm maturation and represents a critical window of susceptibility to environmentally-induced epigenetic errors that may, in turn, influence reproductive health. Emerging animal and human data indicate that male reproductive health is associated with epigenetic dysregulation in sperm. Moreover, recent evidence indicates that epigenetic information retained in mature sperm is enriched at developmental and imprinted genes, signifying that epigenetic patterns in sperm may be important for embryonic development after fertilization. To achieve our research objectives, we will: 1) examine the relationships between paternal urinary phthalate exposure on sperm DNA methylation at imprinted genes and by Illumina's 450K epigenomic array;2) examine the influence of paternal phthalate exposure on sperm quality and embryo development;3) use statistical mediation to examine if sperm methylation is a pathway by which paternal phthalates influence sperm and embryo quality. This study is innovative because: 1) while many epigenetic studies in humans are hampered by DNA from mixed cell types (e.g., leukocytes), our study utilizes a single cell type - sperm germ cells;2) it will provide, to our knowledge, the first human data on the association between phthalate exposure and sperm DNA methylation through the use of both targeted gene and epigenomic approaches;and 3) it may challenge the current dogma of reproductive health by providing novel data on paternal environmental contributions to reproductive success.
The proposed research will be the first, to our knowledge, to examine the associations between paternal phthalate exposure, sperm epigenetics and reproductive health. Such data may transform our understanding of the environmental determinants of male reproductive health and early-life development by emphasizing paternal environmental contributions to reproductive success. Understanding how paternal environmental exposures influence early-life development, via sperm epigenetics, may open avenues of translational research utilizing DNA methylation markers to develop novel approaches for the treatment and prevention of adverse health in early life.
|Wu, Haotian; Huffman, Alexandra M; Whitcomb, Brian W et al. (2018) Sperm mitochondrial DNA measures and semen parameters among men undergoing fertility treatment. Reprod Biomed Online :|
|Pilsner, J Richard; Shershebnev, Alex; Medvedeva, Yulia A et al. (2018) Peripubertal serum dioxin concentrations and subsequent sperm methylome profiles of young Russian adults. Reprod Toxicol 78:40-49|
|Huffman, Alexandra M; Wu, Haotian; Rosati, Allyson et al. (2018) Associations of urinary phthalate metabolites and lipid peroxidation with sperm mitochondrial DNA copy number and deletions. Environ Res 163:10-15|
|Wu, Haotian; Olmsted, Alexandra; Cantonwine, David E et al. (2017) Urinary phthalate and phthalate alternative metabolites and isoprostane among couples undergoing fertility treatment. Environ Res 153:1-7|
|Wu, Haotian; Estill, Molly S; Shershebnev, Alexander et al. (2017) Preconception urinary phthalate concentrations and sperm DNA methylation profiles among men undergoing IVF treatment: a cross-sectional study. Hum Reprod 32:2159-2169|
|Wu, Haotian; Ashcraft, Lisa; Whitcomb, Brian W et al. (2017) Parental contributions to early embryo development: influences of urinary phthalate and phthalate alternatives among couples undergoing IVF treatment. Hum Reprod 32:65-75|
|Pilsner, J Richard; Parker, Mikhail; Sergeyev, Oleg et al. (2017) Spermatogenesis disruption by dioxins: Epigenetic reprograming and windows of susceptibility. Reprod Toxicol 69:221-229|
|Wu, Haotian; de Gannes, Matthew K; Luchetti, Gianna et al. (2015) Rapid method for the isolation of mammalian sperm DNA. Biotechniques 58:293-300|
|Wu, Haotian; Hauser, Russ; Krawetz, Stephen A et al. (2015) Environmental Susceptibility of the Sperm Epigenome During Windows of Male Germ Cell Development. Curr Environ Health Rep 2:356-66|