IL-10 from plasmacytoid dendritic cells promotes angiogenesis in the early stage of endometriosis
JOURNAL OF PATHOLOGY
Authors: Suen, Jau-Ling; Chang, Yu; Shiu, Yu-Shiang; Hsu, Chia-Yi; Sharma, Pooja; Chiu, Chien-Chih; Chen, Yi-Ju; Hour, Tzyh-Chyuan; Tsai, Eing-Mei
Abstract
An elevated level of IL-10 has been considered a critical factor for the development of endometriosis; however, its detailed mechanism and causal relationship remain unclear. This study explored the cellular source and angiogenic activity of local IL-10 during the early stage of endometriosis. Using a surgical murine model, we found that localised treatment with exogenous recombinant IL-10 on the day of surgery significantly enhanced endometriotic lesion growth and angiogenesis, whereas blocking local IL-10 activity using mAbs significantly suppressed those effects. Adoptive transfer of Il10(+/+) plasmacytoid dendritic cells into mice significantly enhanced lesion development, whereas Il10(-/-) plasmacytoid dendritic cells significantly inhibited lesion development. Furthermore, in vitro angiogenesis analyses demonstrated that the IL-10 and IL-10 receptor pathway stimulated the migratory and tube formation ability of HUVECs as well as ectopic endometrial mesenchymal stem cells through, at least in part, a VEGF-dependent pathway. We also found that recombinant IL-10 directly stimulated angiogenesis, based on a Matrigel plug assay as well as a zebrafish model. Pathological results from human endometrioma tissues showed the increased infiltration of CD123(+) plasmacytoid dendritic cells and higher percentages of cells that express the IL-10 receptor and CD31 as compared with the corresponding normal counterparts. Taken together, these results show that IL-10 secreted from local plasmacytoid dendritic cells promotes endometriosis development through pathological angiogenesis during the early disease stage. This study provides a scientific basis for a potential therapeutic strategy targeting the IL-10-IL-10 receptor pathway in the endometriotic milieu. (c) 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Complement peptide C3a receptor 1 promotes optic nerve degeneration in DBA/2J mice
JOURNAL OF NEUROINFLAMMATION
Authors: Harder, Jeffrey M.; Williams, Pete A.; Braine, Catherine E.; Yang, Hongtian S.; Thomas, Jocelyn M.; Foxworth, Nicole E.; John, Simon W. M.; Howell, Gareth R.
Abstract
Background The risk of glaucoma increases significantly with age and exposure to elevated intraocular pressure, two factors linked with neuroinflammation. The complement cascade is a complex immune process with many bioactive end-products, including mediators of inflammation. Complement cascade activation has been shown in glaucoma patients and models of glaucoma. However, the function of complement-mediated inflammation in glaucoma is largely untested. Here, the complement peptide C3a receptor 1 was genetically disrupted in DBA/2J mice, an ocular hypertensive model of glaucoma, to test its contribution to neurodegeneration. Methods A null allele of C3ar1 was backcrossed into DBA/2J mice. Development of iris disease, ocular hypertension, optic nerve degeneration, retinal ganglion cell activity, loss of RGCs, and myeloid cell infiltration in C3ar1-deficient and sufficient DBA/2J mice were compared across multiple ages. RNA sequencing was performed on microglia from primary culture to determine global effects of C3ar1 on microglia gene expression. Results Deficiency in C3ar1 lowered the risk of degeneration in ocular hypertensive mice without affecting intraocular pressure elevation at 10.5 months of age. Differences were found in the percentage of mice affected, but not in individual characteristics of disease progression. The protective effect of C3ar1 deficiency was then overcome by additional aging and ocular hypertensive injury. Microglia and other myeloid-derived cells were the primary cells identified that express C3ar1. In the absence of C3ar1, microglial expression of genes associated with neuroinflammation and other immune functions were differentially expressed compared to WT. A network analysis of these data suggested that the IL10 signaling pathway is a major interaction partner of C3AR1 signaling in microglia. Conclusions C3AR1 was identified as a damaging neuroinflammatory factor. These data help suggest complement activation causes glaucomatous neurodegeneration through multiple mechanisms, including inflammation. Microglia and infiltrating myeloid cells expressed high levels of C3ar1 and are the primary candidates to mediate its effects. C3AR1 appeared to be a major regulator of microglia reactivity and neuroinflammatory function due to its interaction with IL10 signaling and other immune related pathways. Targeting myeloid-derived cells and C3AR1 signaling with therapies is expected to add to or improve neuroprotective therapeutic strategies.