In addition, we further compared the differentially expressed gene sets identified above. A heatmap of the expression patterns of these differentially expressed gene sets is shown in
Figure 3C. The comparison of the significantly DEGs at both infection time points showed that there were three commonly downregulated genes, including
GLDC (glycine decarboxylase),
ALDH1A1 (aldehyde dehydrogenase family 1, subfamily A1), and
PPP1R3C (protein phosphatase 1, regulatory subunit 3C). There were 49 commonly upregulated genes in both groups, such as
CASP12 (caspase 12) and
IL1R2 (interleukin 1 receptor, type II). Interestingly, 33 genes, including the
IL1B gene, were upregulated in the comparison of Af-2/PBS-2 but downregulated in the comparison of Af-5/Af-2. A total of 93 genes, including the
WNT5A gene (wingless-type MMTV integration site family, member 5A), were downregulated in the comparison of Af-2/PBS-2 but upregulated in the comparison of Af-5/Af-2. The details of the results described above are shown in
Figure 3D and
Table 2. Most of these commonly identified genes have been reported in previous studies of fungal ophthalmopathy or immunology. IL-1α and IL-1β are two types of IL-1, which is a cytokine that is produced by monocytes, endothelial cells, fibroblasts, and other types of cells in response to infection that bind to the same receptor of the immunoglobulin superfamily. Previous studies have shown that IL-1β derived from neutrophils participates in corneal antifungal responses and immune defense as an important proinflammatory factor.
24 IL-1β production can be induced by fungal infection in the mouse cornea, and this production can be regulated by the Dectin-1/Syk pathway.
25 Casp11 and Casp1 participate in the modification of IL-1β from its precursor to mature form.
26,27 Wnt5a is a secretory glycoprotein and a member of the highly conserved Wnt protein family.
WNT5A expression regulation and signal transduction are closely related to the inflammatory response, suggesting that
WNT5A and its signaling pathway play an important role in the occurrence and development of inflammatory diseases. According to in vivo and in vitro experiments,
WNT5A was identified as a critical component of the antifungal immune response that can produce Dectin-1- and LOX-1-induced inflammatory signatures in response to
A. fumigatus infection.
28 Caspase-12 may play an important role in the process of hypersensitivity to oxidative stress in keratoconus (KT) cornea fibroblasts.
29 Through analysis of gene expression profile data,
GLDC was identified as playing a significant role in regulating various inflammatory processe
s.30,31 Aldehyde dehydrogenase (ALDH1A1) was found to be expressed in immature monocyte-derived dendritic cells; ALDH1A1 is an enzyme that contributes to the production of retinoic acid and is an important immunomodulator that regulates HIV-1 replication.
32