Development of BRD4 inhibitors as anti-inflammatory agents and antidotes for arsenicals.

Arsenicals belong to the class of chemical warfare agents known as vesicants, which are highly reactive, toxic and cause robust inflammatory response. Cutaneous exposure to arsenicals causes a wide range of systemic organ damage, beginning with cutaneous injuries, and later manifest multi-organ damage and death. Thus, the development of suitable antidotes that can effectively block injury following exposure to these agents is of great importance. Bromodomain 4 (BRD4), a member of the bromodomain and extra terminal domain (BET) family, plays crucial role in regulating transcription of inflammatory, proliferation and cell cycle genes. In this context, the development of potent small molecule inhibitors of BRD4 could serve as potential antidotes for arsenicals. Herein, we describe the synthesis and biological evaluation of a series of compounds.

Identification of Cytoprotective Small-Molecule Inducers of Heme-Oxygenase-1.

Acute kidney injury (AKI) is a major public health concern with significant morbidity and mortality and no current treatments beyond supportive care and dialysis. Preclinical studies have suggested that heme-oxygenase-1 (HO-1), an enzyme that catalyzes the breakdown of heme, has promise as a potential therapeutic target for AKI. Clinical trials involving HO-1 products (biliverdin, carbon monoxide, and iron), however, have not progressed beyond the Phase ½ level. We identified small-molecule inducers of HO-1 that enable us to exploit the full therapeutic potential of HO-1, the combination of its products, and yet-undefined effects of the enzyme system. Through cell-based, high-throughput screens for induction of HO-1 driven by the human HO-1 promoter/enhancer, we identified two novel small molecules and broxaldine (an FDA-approved drug) for further consideration as candidate compounds exhibiting an Emax ≥70% of 5 µM hemin and EC50 <10 µM. RNA sequencing identified shared binding motifs to NRF2, a transcription factor known to regulate antioxidant genes, including HMOX1. In vitro, the cytoprotective function of the candidates was assessed against cisplatin-induced cytotoxicity and apoptosis. In vivo, delivery of a candidate compound induced HO-1 expression in the kidneys of mice. This study serves as the basis for further development of small-molecule HO-1 inducers as preventative or therapeutic interventions for a variety of pathologies, including AKI.

Acoustic Droplet Ejection Applications for High-Throughput Screening of Infectious Agents.

When acoustic droplet ejection technology was first introduced for high-throughput applications, it was used primarily for dispensing compounds dissolved in DMSO. The high precision and accuracy achieved for low-volume transfers in this application were noted by those working outside of the compound management area, and interest was generated in expanding the scope of the technology to include other liquid types. Later-generation instruments included calibrations for several aqueous buffers that were applicable to the life sciences. The High Throughput Screening Center at Southern Research has made use of this range of liquid calibrations for the Infectious Disease Program. The original calibration for DMSO has allowed the preparation of assay-ready plates that can be sent to remote locations. This process was used as part of the collaboration between Southern Research and Galveston National Laboratory, University of Texas Medical Branch, to develop high-throughput screening for biological safety level 4 containment and to provide compounds for two pilot screens that were run there with BSL-4-level pathogens. The aqueous calibrations have been instrumental in miniaturizing assays used for infectious disease, such as qPCR, tissue culture infectious dose 50, and bacterial motility, to make them compatible with HTS operations.