Integrative metabolomics and transcriptomics identifies itaconate as an adjunct therapy to treat ocular bacterial infection

Abstract

Integrative metabolomics and transcriptomics identifies itaconate as an adjunct therapy to treat ocular bacterial infection Graphical abstract Highlights d Bacterial infection increases Irg1 and itaconate levels in the eye d Irg1 and Nrf2 deficiency exacerbates intraocular bacterial infection d Itaconate potentiates antioxidant NRF2/HO-1 signaling in the eye d Itaconate treatment synergizes with antibiotics in ameliorating ocular infection

Bacterial Burden Declines But Neutrophil Infiltration and Ocular Tissue Damage Persist in Experimental Staphylococcus epidermidis Endophthalmitis

“…Because different pathogens cause experimental endophthalmitis at certain infectious doses ( Gupta et al., 2019 ; Francis et al., 2020 ; Kumar et al., 2020 ; Livingston et al., 2021 ), we performed a dose-response study beginning with an intravitreal injection of 5,000 cfu of S. epidermidis , a dose required for S. aureus endophthalmitis ( Singh et al., 2021 ). However, this inoculum was rapidly cleared from the mouse eyes resulting in transient inflammation (data not shown).…”

“…Human RPE cells also exhibited a similar pattern of IL-1β and TNF-α mRNA ( Figure 7C ) and protein ( Figure 7D ) expression in response to S. epidermidis infection. PMNs and monocytes/macrophages are also major infiltrating innate immune cells during ocular infections ( Singh et al., 2021 ); therefore, we decided to assess the inflammatory response of mouse BMDMs. To this end, our data showed that S. epidermidis induced robust Il-6 and Cxcl1 mRNA ( Figure 7E ) and protein expressions ( Figure 7F ) in cultured BMDMs.…”

DataSheet_1.docx

“…Because different pathogens cause experimental endophthalmitis at certain infectious doses (Gupta et al, 2019;Francis et al, 2020;Kumar et al, 2020;Livingston et al, 2021), we performed a doseresponse study beginning with an intravitreal injection of 5,000 cfu of S. epidermidis, a dose required for S. aureus endophthalmitis (Singh et al, 2021). However, this inoculum was rapidly cleared from the mouse eyes resulting in transient inflammation (data not shown).…”

“…Human RPE cells also exhibited a similar pattern of IL-1b and TNF-a mRNA (Figure 7C) and protein (Figure 7D) expression in response to S. epidermidis infection. PMNs and monocytes/ macrophages are also major infiltrating innate immune cells during ocular infections (Singh et al, 2021); therefore, we decided to assess the inflammatory response of mouse BMDMs. To this end, our data showed that S. epidermidis induced robust Il-6 and Cxcl1 mRNA (Figure 7E) and protein expressions (Figure 7F) in cultured BMDMs.…”

“…Mice were anesthetized with ketamine and xylazine, and intravitreal injections of PBS or bacteria (2-ml volume) were performed using a 34-gauge needle under a microscope. This procedure is routinely performed in the lab and reported in our several studies (Kumar et al, 2010;Talreja et al, 2014;Kumar et al, 2016;Singh et al, 2020;Singh et al, 2021). Disease progression was monitored using slit-lamp examination and testing retinal function using electroretinogram (ERG).…”