Uptake of cell debris and enhanced expression of inflammatory factors in response to dead cells in corneal fibroblast cells
EXPERIMENTAL EYE RESEARCH
Authors: Yoon, Heejei; Choi, Seung-Il; Kim, Eung Kweon
Abstract
Keratocytes synthesize stromal proteins and participate in wound healing through successive differentiation into corneal fibroblasts and myofibroblasts. Cultured keratocytes or corneal fibroblasts are also known as non-professional phagocytes and innate immune cells. However, whether the corneal fibroblasts phagocytize their dead cells and whether the associated innate immunity is enhanced remains unknown. We initially characterized immortalized corneal fibroblast cells with the expression of specific genes. The corneal fibroblasts strongly expressed extracellular matrix molecules (FN and COL1A1) and low or medium levels of macrophage markers (CD14, CD68, and CD36), inflammatory cytokines (IL1A, IL1B, and IL6), and chemokines (IL8 and CCL2), but not CD11b, suggesting that corneal fibroblasts are macrophage-like fibroblasts. We confirmed the phagocytic activity of the corneal fibroblasts with fluorescent dye labeled-dead E. coli and S. aureus bacteria using confocal microscopy and flow cytometry. To test corneal fibroblast phagocytosis of apoptotic and necrotic cells we co-cultured corneal fibroblasts with fluorescent dye labeled-apoptotic and -necrotic cells and analyzed their uptake using fluorescence and confocal microscopy. We observed that corneal fibroblasts can engulf digested or processed cellular debris and entire dead cells. Co-cultured dying and dead cells strongly enhanced the expression of cytokine (IL1A, ILIB, and IL6), chemokine (CCL2, CCL5, CCL20, IL8, and CXCL10), and MMP (MMP1, MMP3, and MMP9) genes through the NF-kappa B signaling pathway. Our findings suggest that dying and dead cells stimulate corneal fibroblasts to further induce inflammatory factors and that corneal fibroblasts contribute to the clearing of cell debris as non-professional phagocytes.
Cytokine gene expression at the maternal-fetal interface after somatic cell nuclear transfer pregnancies in small ruminants
REPRODUCTION FERTILITY AND DEVELOPMENT
Authors: Rutigliano, Heloisa M.; Wilhelm, Amanda; Hall, Justin; Shi, Bi; Meng, Qinggang; Stott, Rusty; Bunch, Thomas D.; White, Kenneth L.; Davies, Christopher J.; Polejaeva, Irina A.
Abstract
The present retrospective study investigated pregnancy rates, the incidence of pregnancy loss and large offspring syndrome (LOS) and immune-related gene expression of sheep and goat somatic cell nuclear transfer (SCNT) pregnancies. We hypothesised that significantly higher pregnancy losses observed in sheep compared with goat SCNT pregnancies are due to the increased amounts of T-helper 1 cytokines and proinflammatory mediators at the maternal-fetal interface. Sheep and goat SCNT pregnancies were generated using the same procedure. Control pregnancies were established by natural breeding. Although SCNT pregnancy rates at 45 days were similar in both species, pregnancy losses between 45 and 60 days of gestation and the incidence of LOS were significantly greater in sheep than in goats. At term, the expression of proinflammatory genes in sheep SCNT placentas was increased, whereas that in goats was similar to that in control animals. Genes with altered expression in sheep SCNT placentas included cytotoxic T-lymphocyte-associated protein 4 (CTLA4), interleukin 2 receptor alpha (IL2RA), cluster of differentiation 28 (CD28), interferon gamma (IFNG), interleukin 6 (IL6), interleukin 10 (IL10), transforming growth factor beta 1 (TGFB1), tumor necrosis factor alpha (TNF-), interleukin 1 alpha (IL1A) and chemokine (C-X-C motif) ligand 8 (CXCL8). Major histocompatibility complex-I protein expression was greater in sheep and goat SCNT placentas at term than in control pregnancies. An unfavourable immune environment is present at the maternal-fetal interface in sheep SCNT pregnancies.