A Descriptive Cohort Study of Drug Utilization Patterns Among Patients Hospitalized With Coronavirus Disease 2019 in the United States, January 2021-February 2022.

Background: There is a dearth of drug utilization studies for coronavirus disease 2019 (COVID-19) treatments in 2021 and beyond after the introduction of vaccines and updated guidelines; such studies are needed to contextualize ongoing COVID-19 treatment effectiveness studies during these time periods. This study describes utilization patterns for corticosteroids, interleukin-6 (IL-6) inhibitors, Janus kinase inhibitors, and remdesivir among hospitalized adults with COVID-19, over the entire hospitalization, and within hospitalization periods categorized by respiratory support requirements. Methods: This descriptive cohort study included United States adults hospitalized with COVID-19 admitted from 1 January 2021 through 1 February 2022; data included HealthVerity claims and hospital chargemaster. The number and distribution of patients were reported for the first 3 drug regimen lines initiated. Results: The cohort included 51 066 patients; the most common initial drug regimens were corticosteroids (23.4%), corticosteroids plus remdesivir (25.1%), and remdesivir (4.4%). IL-6 inhibitors and Janus kinase inhibitors were included in later drug regimens and were more commonly administered with both corticosteroids and remdesivir than with corticosteroids alone. IL-6 inhibitors were more commonly administered than Janus kinase inhibitors when patients received high-flow oxygen or ventilation. Conclusions: These findings provide important context for comparative studies of COVID-19 treatments with study periods extending into 2021 and later. While prescribing generally aligned with National Institutes of Health COVID-19 treatment guidelines during this period, these findings suggest that prescribing preference, potential confounding by indication, and confounding by prior/concomitant use of other therapeutics should be considered in the design and interpretation of comparative studies.

Identification of the IL-33 protein segment that controls subcellular localization, extracellular secretion, and functional maturation.

Proteolytic activation of the IL-33 precursor, full-length interleukin-33 (FLIL33), at multiple sites within the sensor domain (aa 95-109) yields several functionally mature (MIL33) forms. Unlike nuclear FLIL33, intracellular MIL33 occurs in the cytoplasm, is secreted from source cells, and exerts biological effects by activating the ST2 receptor on target cells. Previous studies and our findings in this report indicated that IL-33 forms that are substantially longer than those produced by cleavage within the sensor domain are biologically indistinguishable from classical MIL33. We utilized a series of human and mouse N-terminal FLIL33 mutants to narrow down the boundaries of the nuclear localization sequence to aa 46-67, a segment known to include a portion of the chromatin-binding motif as well as another site controlling intracellular stability of FLIL33 in an importin-5-dependent fashion. The N-terminal FLIL33 deletion mutants starting prior to this region were intranuclear, non-secreted in cell culture, and manifested modest functional activity in vivo, similar to FLIL33. By contrast, the mutants starting after this region were cytoplasmic, secreted from cells in culture, and overtly biologically active in vivo, similar to MIL33. The deletion mutants starting within this region manifested an intermediate phenotype between FLIL33 and MIL33. Thus, this segment of IL-33 molecule controls multiple aspects of its biology, including subcellular localization, extracellular secretion, and functional maturation into the longest possible form of mature IL-33 cytokine. Future anti-IL-33 therapies may be based on interfering with this segment, thus restraining extracellular release and maturation of IL-33 into the active cytokine.

Transcriptomic evidence of immune activation in macroscopically normal-appearing and scarred lung tissues in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease manifested by overtly scarred peripheral and basilar regions and more normal-appearing central lung areas. Lung tissues from macroscopically normal-appearing (IPFn) and scarred (IPFs) areas of explanted IPF lungs were analyzed by RNASeq and compared with healthy control (HC) lung tissues. There were profound transcriptomic changes in IPFn compared with HC tissues, which included elevated expression of numerous immune-, inflammation-, and extracellular matrix-related mRNAs, and these changes were similar to those observed with IPFs compared to HC. Comparing IPFn directly to IPFs, elevated expression of epithelial mucociliary mRNAs was observed in the IPFs tissues. Thus, despite the known geographic tissue heterogeneity in IPF, the entire lung is actively involved in the disease process, and demonstrates pronounced elevated expression of numerous immune-related genes. Differences between normal-appearing and scarred tissues may thus be driven by deranged epithelial homeostasis or possibly non-transcriptomic factors.

The full-length interleukin-33 (FLIL33)-importin-5 interaction does not regulate nuclear localization of FLIL33 but controls its intracellular degradation.

Human mature IL-33 is a member of the IL-1 family and a potent regulator of immunity through its pro-T helper cell 2 activity. Its precursor form, full-length interleukin-33 (FLIL33), is an intranuclear protein in many cell types, including fibroblasts, and its intracellular levels can change in response to stimuli. However, the mechanisms controlling the nuclear localization of FLIL33 or its stability in cells are not understood. Here, we identified importin-5 (IPO5), a member of the importin family of nuclear transport proteins, as an intracellular binding partner of FLIL33. By overexpressing various FLIL33 protein segments and variants in primary human lung fibroblasts and HEK293T cells, we show that FLIL33, but not mature interleukin-33, physically interacts with IPO5 and that this interaction localizes to a cluster of charged amino acids (positions 46-56) but not to an adjacent segment (positions 61-67) in the FLIL33 N-terminal region. siRNA-mediated IPO5 knockdown in cell culture did not affect nuclear localization of FLIL33. However, the IPO5 knockdown significantly decreased the intracellular levels of overexpressed FLIL33, reversed by treatment with the 20S proteasome inhibitor bortezomib. Furthermore, FLIL33 variants deficient in IPO5 binding remained intranuclear and exhibited decreased levels, which were also restored by the bortezomib treatment. These results indicate that the interaction between FLIL33 and IPO5 is localized to a specific segment of the FLIL33 protein, is not required for nuclear localization of FLIL33, and protects FLIL33 from proteasome-dependent degradation.

Stimulation of PGE receptors EP2 and EP4 protects cultured neurons against oxidative stress and cell death following beta-amyloid exposure.

Alzheimer's disease (AD) is associated with gliosis, neuroinflammation and higher levels of prostaglandins. Conflicting roles for cyclooxygenases and prostaglandins in the etiopathology of AD have been reported. We hypothesized that PGE2 signaling through EP2 and EP4 G-protein-coupled receptors could protect against amyloid beta-peptide (Abeta) neurotoxicity by increasing the cAMP signaling cascade. Using primary neuronal cultures, we investigated the presence of EP receptors (EP1-4) and the action of PGE2 and EP receptor agonists on neuronal susceptibility to Abeta1-42 toxicity. Low concentrations (1 microm) of PGE2, butaprost (EP2 agonist), and 1-hydroxy-PGE1 (EP4/EP3 agonist) were neuroprotective against Abeta1-42 toxicity, while sulprostone (EP3/EP1 agonist) at similar doses had no detectable effects. EP2 and EP4 receptor-mediated neuroprotection would involve changes in cAMP levels, as both EP2 and EP4 agonists increased intracellular cAMP concentration by approximately doubling basal levels, and both exhibited neuroprotective actions against Abeta-induced toxicity. The protein kinase A (PKA) inhibitor RpcAMPS significantly attenuated the neuroprotection by butaprost, but not that by 1-hydroxy-PGE1, implying differences between EP2 and EP4 receptor protective mechanisms. Additionally, the increase in reactive oxygen species generated following exposure to Abeta was reduced by stimulation of both EP2 and EP4 receptors. Together, these results indicate that PGE2 can protect neurons against Abeta toxicity by acting on given receptors and stimulating a cascade of intracellular events, including the cAMP-PKA pathway. We propose that development and testing of specific PGE2 receptor agonists downstream of cyclooxygenase could lead to therapeutic applications.