A screen for protective drugs against delayed hypoxic injury

Abstract

Despite longstanding efforts to develop cytoprotective drugs against ischemia/reperfusion (IR) injuries, there remains no effective therapeutics to treat hypoxic injury. The failure of traditional strategies at solving this problem suggests the need for novel and unbiased approaches that can lead to previously unsuspected targets and lead compounds. Towards this end, we report here a unique small molecule screen in the nematode C. elegans for compounds that improve recovery when applied after the hypoxic insult, using a C. elegans strain engineered to have delayed cell non-autonomous death. In a screen of 2000 compounds, six were found to produce significant protection of C. elegans from delayed death. Four of the compounds were tested in an ex vivo mouse heart ischemia/reperfusion model and two, meclocycline and 3-amino-1,2,4-triazole, significantly reduced infarction size. Our work demonstrates the feasibility of this novel C. elegans screen to discover hypoxia protective drugs that are also protective in a mammalian model of hypoxic injury.

Cardioprotection by the mitochondrial unfolded protein response (UPRmt) is mediated by activating transcription factor 5 (ATF5)

“…The ability of doxycycline to induce acute cardioprotection was also tested, by delivering the drug to ex-vivo perfused hearts prior to ischemia and during reperfusion. However, in contrast to previous reports (29), no significant protective effect was observed (functional recovery: doxycycline 40±19% vs. vehicle 34±9%, p=0.78; infarct: doxycycline 66±6% vs. vehicle 49±5%, p=0.11) ( Fig. 3E/F).…”

“…Although herein we chose a 6 h delay between drug administration and IR injury, to permit induction of the UPR mt gene program, a recent report claimed acute cardioprotection by tetracycline antibiotics delivered 30 min prior to ischemia (29). Our inability to reproduce this phenomenon may have been due to an observed low solubility of doxycycline in Krebs-Henseleit perfusion buffer, such that the microfiltration necessary for successful mouse cardiac perfusion (37) may have limited doxycycline bioavailability in our experiments.…”

Novel Prodiginine Derivatives Demonstrate Bioactivities on Plants, Nematodes, and Fungi

“…We first tested all compounds against the model nematode C. elegans and the plant parasitic nematode H. schachtii in direct exposure assays. The nematode C. elegans is frequently used in studies involved in investigating compounds’ bioactivities against multicellular organisms ( Sun et al, 2017 ; Al Banna et al, 2018 ; Liao, 2018 ). The nematode H. schachtii is one of the devastating pathogens of several economically valuable crops ( Steele, 1965 ; Muller, 1999 ).…”

Deep learning detects cardiotoxicity in a high-content screen with induced pluripotent stem cell-derived cardiomyocytes

“…The screening window, commonly assessed using the Z-factor, ensures detection of true-positive hits and limits the number of false-negative and false-positive hits. Additionally, most published studies have been limited to single-readout phenotypes, such as cell survival ( Sharma et al, 2017 ; Sun et al, 2017 ), expression of a single marker ( Ghazizadeh and Majd, 2020 ), or reporter screens ( McLendon et al, 2017 ). While these studies revealed great insight into cardiomyocyte biology, they have not described a general and unbiased screening strategy that can be applied to other cell types and used at scale.…”