Embryonic Resorption and Polycyclic Aromatic Hydrocarbons: Putative Immune-mediated Mechanisms

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are released into the environment as a result of incomplete fossil fuel combustion from industrial furnaces, woodburning stoves, and automobile exhaust fumes; however, the primary source of human exposure to these compounds is cigarette smoke. Embryonic and fetal loss after treatment with high doses of PAHs have been well documented in animal studies; however, few studies have addressed the reproductive consequences of long-term, low-level exposure to these chemicals. We previously reported that low doses of PAHs administered to ICR mice over a period of 9 weeks prior to conception resulted in early embryonic resorptions, whereby treated dams lost approximately 50% of their litter. During the course of these studies, we observed greater numbers of infiltrating uterine natural killer (uNK) cells into the placenta of PAH-exposed conceptuses. While exposure to high levels of PAHs has been shown to be immunosuppressive, increasing evidence suggests that chronic, low-dose exposure to PAHs may stimulate immune cells. Thus, we hypothesized that low-dose, chronic PAH exposure in our mouse model is mediating embryonic resorption by hyperstimulating maternal immune cells. In this review of the literature, we outline the rationale of our argument and present preliminary data, focussing upon PAH-mediated alterations in uNK cell dynamics and how these changes may be linked to early embryonic resorptions.

Low reproductive success rates of common bottlenose dolphins Tursiops truncatus in the northern Gulf of Mexico following the Deepwater Horizon disaster (2010-2015)

“…Posterior probability distributions for the difference in reproductive success between the DWH-oiled GoM stocks of bottlenose dolphins and non-oiled reference stocks at (top to bottom) 1, 2 and 3 times the observed reproductive success rate of the oiled GoM stocks. The point estimates for reproductive success were 0.222 and 0.647 for the oiled and reference stocks, respectively re sorption (Detmar & Jurisicova 2010). Crude-oil exposed rats exhibit high perinatal mortality with up to 72% of parturitions of ex posed pregnancies concluding in still births (Nwaigwe et al 2012), and fetal survival rates decreasing by as much as 3-fold in offspring whose mothers were exposed to the pyrogenic PAH benzo(a)pyrene (Bui et al 1986, Archibong et al 2002.…”

“…Impairment of vertebrate immune systems is a commonly observed effect of PAH and general petroleum exposure, and increased susceptibility to infection has been documented in association with the DWH oil spill (Detmar & Jurisicova 2010, Whitehead et al 2012, Whitehead 2013, Ali et al 2014, VennWatson et al 2015a, S. De Guise et al 2017. Of course, numerous infectious agents and abnormal inflammatory responses can in turn cause reproductive failure and impair early development (Wilson et al 2015).…”

Evaluation of three extraction methods for the isolation of PAHs from recycled paperboard materials intended for food contact applications

“…PAHs, a diverse group of organic compounds, are one of the most widespread pollutants with proven adverse effects on various living organisms, including humans [25][26][27][28][29]. However, despite their toxicity, PAHs are inextricably integrated into everyday life due to their presence in staple products such as toys, shoes, as well as foodstuffs.…”

Whole Genome Expression in Peripheral-Blood Samples of Workers Professionally Exposed to Polycyclic Aromatic Hydrocarbons

“…5,6 Besides their carcinogenesis property, PAHs can affect various organ functions, such as immunologic response and reproductive function. 7-10 PAHs are present in complex mixtures of more than 100 different compounds in the vicinity of coke-oven areas. 3 Our earlier studies have demonstrated that urinary 1-hydroxypyrene (1OHP), a metabolite of pyrene, is a good index of external ambient exposure to PAHs in COW.…”

“…Coke-oven workers (COWs) are exposed to high concentrations of polycyclic aromatic hydrocarbons (PAHs), which are also the major hazards from cigarette smoking and traffic pollutants. − Some PAHs with four or more benzene rings are considered to be human carcinogens . Epidemiologic studies have presented strong evidence that workers with long-term exposure to PAHs have a high incidence of cancer, especially lung and colon cancers. , Besides their carcinogenesis property, PAHs can affect various organ functions, such as immunologic response and reproductive function. − PAHs are present in complex mixtures of more than 100 different compounds in the vicinity of coke-oven areas . Our earlier studies have demonstrated that urinary 1-hydroxypyrene (1OHP), a metabolite of pyrene, is a good index of external ambient exposure to PAHs in COWs. − …”