Assessment of mustard vesicant lung injury and anti-TNF-α efficacy in rodents using live-animal imaging

Overlapping Science in Radiation and Sulfur Mustard Exposures of Skin and Lung: Consideration of Models, Mechanisms, Organ Systems, and Medical Countermeasures: Overlapping science in radiation and sulfur mustard injuries to lung and skin

PURPOSE

To summarize presentations and discussions from the 2022 trans-agency workshop titled "Overlapping science in radiation and sulfur mustard (SM) exposures of skin and lung: Consideration of models, mechanisms, organ systems, and medical countermeasures."

METHODS

Summary on topics includes: (1) an overview of the radiation and chemical countermeasure development programs and missions; (2) regulatory and industry perspectives for drugs and devices; 3) pathophysiology of skin and lung following radiation or SM exposure; 4) mechanisms of action/targets, biomarkers of injury; and 5) animal models that simulate anticipated clinical responses.

RESULTS

There are striking similarities between injuries caused by radiation and SM exposures. Primary outcomes from both types of exposure include acute injuries, while late complications comprise chronic inflammation, oxidative stress, and vascular dysfunction, which can culminate in fibrosis in both skin and lung organ systems. This workshop brought together academic and industrial researchers, medical practitioners, US Government program officials, and regulators to discuss lung-, and skin- specific animal models and biomarkers, novel pathways of injury and recovery, and paths to licensure for products to address radiation or SM injuries.

CONCLUSIONS

Regular communications between the radiological and chemical injury research communities can enhance the state-of-the-science, provide a unique perspective on novel therapeutic strategies, and improve overall US Government emergency preparedness.

Targeting Tumor Necrosis Factor Alpha to Mitigate Lung Injury Induced by Mustard Vesicants and Radiation

Pulmonary injury induced by mustard vesicants and radiation is characterized by DNA damage, oxidative stress, and inflammation. This is associated with increases in levels of inflammatory mediators, including tumor necrosis factor (TNF)α in the lung and upregulation of its receptor TNFR1. Dysregulated production of TNFα and TNFα signaling has been implicated in lung injury, oxidative and nitrosative stress, apoptosis, and necrosis, which contribute to tissue damage, chronic inflammation, airway hyperresponsiveness, and tissue remodeling. These findings suggest that targeting production of TNFα or TNFα activity may represent an efficacious approach to mitigating lung toxicity induced by both mustards and radiation. This review summarizes current knowledge on the role of TNFα in pathologies associated with exposure to mustard vesicants and radiation, with a focus on the therapeutic potential of TNFα-targeting agents in reducing acute injury and chronic disease pathogenesis.

Effects of Overexpression of Fibroblast Growth Factor 15/19 on Hepatic Drug Metabolizing Enzymes

Fibroblast growth factors 15 (FGF15) and 19 (FGF19) are endocrine growth factors that play an important role in maintaining bile acid homeostasis. FGF15/19-based therapies are currently being tested in clinical trials for the treatment of nonalcoholic steatohepatitis and cholestatic liver diseases. To determine the physiologic impact of long-term elevations of FGF15/19, a transgenic mouse model with overexpression of Fgf15 (Fgf15 Tg) was used in the current study. The RNA sequencing (RNA-seq) analysis revealed elevations of the expression of several genes encoding phase I drug metabolizing enzymes (DMEs), including Cyp2b10 and Cyp3a11, in Fgf15 Tg mice. We found that the induction of several Cyp2b isoforms resulted in increased function of CYP2B in microsomal metabolism and pharmacokinetics studies. Because the CYP2B family is known to be induced by constitutive androstane receptor (CAR), to determine the role of CAR in the observed inductions, we crossed Fgf15 Tg mice with CAR knockout mice and found that CAR played a minor role in the observed alterations in DME expression. Interestingly, we found that the overexpression of Fgf15 in male mice resulted in a phenotypical switch from the male hepatic expression pattern of DMEs to that of female mice. Differences in secretion of growth hormone (GH) between male and female mice are known to drive sexually dimorphic, STAT5b-dependent expression patterns of hepatic genes. We found that male Fgf15 Tg mice presented with many features similar to GH deficiency, including lowered body length and weight, Igf-1 and Igfals expression, and STAT5 signaling. SIGNIFICANCE STATEMENT: The overexpression of Fgf15 in mice causes an alteration in DMEs at the mRNA, protein, and functional levels, which is not entirely due to CAR activation but associated with lower GH signaling.

Effects and early diagnostic value of lncRNA H19 on sepsis‑induced acute lung injury

Sepsis is an immune disease induced by microbial invasion. The molecular mechanism and value of long non-coding H19 (lncRNA H19) in sepsis remain largely unknown. The present study aimed to investigate the effects and early diagnostic value of lncRNA H19 on sepsis-induced acute lung injury (ALI). Serum samples from 85 septic patients and 76 healthy individuals were collected, and the expression of lncRNA H19 was assessed by the quantitative polymerase chain reaction (qPCR). Sprague-Dawley (SD) rats were subjected to cecal ligation and puncture (CLP) in order to construct models of sepsis-induced ALI. A total of 18 successfully modeled rats were randomly allocated into an lncRNA H19-ad group and a model group, and another 9 healthy SD rats from the same batch were selected as a control group. The samples of serum and lung tissue were collected. lncRNA H19 expression was quantified by qPCR, and levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-17, caspase-3, caspase-9, B-cell lymphoma-2 (Bcl-2), and BCL2-associated X (Bax) were measured by western blotting. A receiver operating characteristic (ROC) curve was employed to assess the diagnostic value of lncRNA H19 for septic patients. lncRNA H19 was downregulated in sepsis. Upregulation of lncRNA H19 inhibited TNF-α, IL-6, IL-17, caspase-3, caspase-9 and Bax and increased Bcl-2. The AUC of lncRNA H19 for early diagnosis of sepsis was 0.8197 (95% CI, 0.77 to 0.91). lncRNA H19 alleviated sepsis-induced ALI by inhibiting pulmonary apoptosis and inflammation, serving as a biochemical marker and therapeutic target for sepsis.