Treatment of Sulfur Mustard Corneal Injury by Augmenting the DNA Damage Response (DDR): A Novel Approach

Senescence and Stress Signaling Pathways in Corneal Cells After Nitrogen Mustard Injury

Mustard gas keratopathy (MGK), a complication of exposure to sulfur mustard, is a blinding ocular surface disease involving key cellular pathways, including apoptosis, oxidative stress, and inflammation. Recent studies indicate that cellular senescence contributes to the pathophysiology of mustard gas toxicity. This study aimed to assess senescence and stress-related pathways-particularly mitogen-activated protein kinase (MAPK) signaling-in nitrogen mustard (NM)-induced corneal injury. In vitro, primary human corneal epithelial (P-HCECs), primary human corneal mesenchymal stromal cells (hcMSCs), and human corneal-limbal epithelial cell (HCLE) lines were exposed to varying concentrations of NM. The results demonstrated a dose-dependent increase in cellular senescence, characterized by reduced Ki67 expression, elevated p16, and p21 mRNA levels, as well as activation of the MAPK pathway activation. Treatment with a selective p38-MAPK inhibitor significantly reduced senescence markers and improved cell proliferation following exposure to NM. Overall, these studies indicate that NM exposure triggers cellular senescence and stress-related MAPK signaling, while p38-MAPK inhibition mitigates these effects, suggesting a potential therapeutic strategy.

Progress and Challenges in Developing Medical Countermeasures for Chemical, Biological, Radiological, and Nuclear Threat Agents

This Commentary delves into the current progress and challenges on ongoing research on medical countermeasures (MCs) for chemical, biologic, radiologic, and nuclear (CBRN) threats. CBRN agents pose a serious risk to human health and safety, with the potential for mass casualties in both military and civilian settings. Chemical threats are toxic compounds that could be used in a terrorist attack, an accidental release, or chemical warfare. They include nerve agents, organophosphates, pulmonary agents, metabolic/cellular agents, vesicants, ocular toxicants, and opioid agents. Developing effective MCs is crucial for mitigating the acute and chronic effects of exposure to CBRN agents. The papers in this special issue of JPET highlights the latest advancements in MC research, showcasing insightful outcomes on experimental models, mechanisms, and translational research on MCs for CBRN threats. They portray several notable contributions, including the development of neurosteroid and combination anticonvulsant therapies for nerve agent poisoning, the exploration of chronic impacts and diagnostic tracers for OP neurotoxicity, the establishment of innovative pediatric OP models, the identification of novel molecules for ocular, pulmonary and vesicant injuries, and the repurposing of existing drugs for the treatment of botulism, cyanide, and OP poisoning. These crucial outcomes underscore the breadth of current research covering a variety of chemical threats. Overall, this collection of articles highlights the importance of ongoing research and development in the field of MCs, emphasizing the potential of these countermeasures to effectively treat and mitigate the effects of toxicant exposures and thereby enhance our preparedness for mass casualty incidents. SIGNIFICANCE STATEMENT: CBRN agents pose a significant threat to public health. Effective MCs exist for certain chemical threats, but there is a need for new and improved MCs for many others. The research presented in this special issue of JPET highlights the latest advancements in MCs for CBRN threats. This research has the potential to lead to the development of new and repurposed MCs that are more effective, broad-spectrum, and easier to administer to mitigate acute and long-term consequences of chemical exposures.