Two-cell embryos are more sensitive than blastocysts to AMPK-dependent suppression of anabolism and stemness by commonly used fertility drugs, a diet supplement, and stress

Abstract

Inducing drug or diet supplements decreased anabolism, growth, and stemness have a greater impact on AMPK-dependent processes in two-cell embryos compared to blastocysts.

AMPK Activity Contributes to G2 Arrest and DNA Damage Decrease via p53/p21 Pathways in Oxidatively Damaged Mouse Zygotes

“…An incomplete repair of DNA damage in 1-cell embryos may lead to more severe DNA damage during later stages of embryonic development and can negatively affect the development and survival of embryos. In addition, activated AMPK affects the cellular function through a variety of processes aimed at restoring the energy balance, including metabolism, mitochondrial biogenesis, autophagy, and potency loss of stem cell and embryo ( Steinberg and Kemp, 2009 ; Novikova et al, 2015 ; Bolnick et al, 2016 , 2017 ; Herzig and Shaw, 2017 ; Pei et al, 2018 ). Moreover, the AMPK inhibitor we used, SBI-0206965, is also an inhibitor of the autophagic kinase ULK1 ( Dite et al, 2018 ), which would inhibit autophagy of embryonic cells.…”

Why AMPK agonists not known to be stressors may surprisingly contribute to miscarriage or hinder IVF/ART

“…Since DS and drugs are generally cleared in hours in vivo, in vitro stimulations tend to be overexposures in regard to biological effects measured in days [5,6]. However, AMPKdependent decreases in anabolism and potency occur within one hour before the peak blood dose is reached and therefore these exposures are not artifacts of in vitro overexposures.…”

“…In the bovine model, cultured two-cell stage embryos are more sensitive to metformin than maturing oocytes for growth and developmental arrest [10]. In the mouse model, the two-cell stage embryo is more sensitive than the blastocyst stage for several AMPK-dependent outcomes [5]. This may support the hypothesis that early post-fertilization events are susceptible to precise energy management, but in vivo data are required to confirm relevance of in vitro outcomes.…”

“…Recent research shows that AMP-activated protein kinase (AMPK) mediates or is associated with stress-driven loss of potency factor proteins in cultured embryonic stem cells (ESCs), placental trophoblast stem cells (TSCs), and AMPK agonists that block reprogramming which produces induced pluripotent stem cells (iPSCs) by preventing switch to Warburg metabolism and blocking Oct4 transcription [1][2][3]. AMPK activity is associated with decreased potency in oocytes [4], and AMPK activity causes potency loss in two-cell embryos [5][6][7] and blastocysts [5,7,8]. AMPK inhibitors, compound C and AraA, block stress-forced potency loss in ESCs, TSC blastocysts, and two-cell embryos suggesting that AMPK mediates potency loss.…”

Using stem cell oxygen physiology to optimize blastocyst culture while minimizing hypoxic stress

“…In Fig. 3b, TSCs were exposed to preequilibrated media at optimal 2% O 2 and the stress enzyme AMP-activated protein kinase (AMPK) was activated at high levels within 6-8 h. This is significant because AMPK integrates energy deficit (i.e., low ATP/high AMP) and decreases anabolism to rebalance ATP but decreases potency in TSCs and embryos in response to many stress stimuli as well as some drugs and diet supplements [46][47][48][49][50][51][52]. Hypothetically, the growth rate and lactate production increases in mouse TSCs and stem cells of the late blastocyst would lead to stress that would ultimately slow growth and be toxic without media change.…”