Uterine deficiency of high-mobility group box-1 (HMGB1) protein causes implantation defects and adverse pregnancy outcomes
CELL DEATH AND DIFFERENTIATION
Authors: Aikawa, Shizu; Deng, Wenbo; Liang, Xiaohuan; Yuan, Jia; Bartos, Amanda; Sun, Xiaofei; Dey, Sudhansu K.
Abstract
A reciprocal communication between the implantation-competent blastocyst and the receptive uterus is essential to successful implantation and pregnancy success. Progesterone (P-4) signaling via nuclear progesterone receptor (PR) is absolutely critical for pregnancy initiation and its success in most eutherian mammals. Here we show that a nuclear protein high-mobility group box-1 (HMGB1) plays a critical role in implantation in mice by preserving P-4-PR signaling. Conditional deletion of uterine Hmgb1 by a Pgr-Cre driver shows implantation defects accompanied by decreased stromal cell Hoxa10 expression and cell proliferation, two known signatures of inefficient responsiveness of stromal cells to PR signaling in implantation. These mice evoke inflammatory conditions with sustained macrophage accumulation in the stromal compartment on day 4 of pregnancy with elevated levels of macrophage attractants Csf1 and Ccl2. The results are consistent with the failure of exogenous P-4 administration to rescue implantation deficiency in the mutant females. These early defects are propagated throughout the course of pregnancy and ultimately result in substantial subfertility. Collectively, the present study provides evidence that nuclear HMGB1 contributes to successful blastocyst implantation by sustaining P-4-PR signaling and restricting macrophage accumulation to attenuate harmful inflammatory responses.
Inflammatory response and MAPK and NF-kappa B pathway activation induced by natural street rabies virus infection in the brain tissues of dogs and humans
VIROLOGY JOURNAL
Authors: Liu, Shu Qing; Xie, Yuan; Gao, Xin; Wang, Qian; Zhu, Wu Yang
Abstract
Background Street rabies virus (RABV) usually infects hosts at peripheral sites and migrates from motor or sensory nerves to the central nervous system. Several studies have found that inflammation is mild in a mouse model of street RABV infection. However, the pathogenetic mechanisms of street RABV in naturally infected dogs or humans are not well understood. Methods Brain tissues collected from 3 dogs and 3 humans were used; these tissue samples were collected under the natural condition of rabies-induced death. The inflammatory response and pathway activation in the brain tissue samples of dogs and humans were evaluated by HE, IHC, ARY006, WB and ELISA. The clinical isolate street RABV strains CGS-17 and CXZ-15 from 30 six-week-old ICR mice were used to construct the mouse infection model presented here. Results Neuronal degeneration and increased lymphocyte infiltration in the cerebral cortex, especially marked activation of microglia, formation of glial nodules, and neuronophagy, were observed in the dogs and humans infected with the street RABV strains. The various levels of proinflammatory chemokines, particularly CXCL1, CXCL12, CCL2, and CCL5, were increased significantly in the context of infection with street RABV strains in dogs and humans in relation to healthy controls, and the levels of MAPK and NF-kappa B phosphorylation were also increased in dogs and humans with natural infection. We also found that the degrees of pathological change, inflammatory response, MAPK and NF-kappa B signaling pathway activation were obviously increased during natural infection in dogs and humans compared with artificial model infection in mice. Conclusion The data obtained here provide direct evidence for the RABV-induced activation of the inflammatory response in a dog infection model, which is a relatively accurate reflection of the pathogenic mechanism of human street RABV infection. These observations provide insight into the precise roles of underlying mechanisms in fatal natural RABV infection.