Upregulation of Fibrinogen-Like 1 Expression Contributes to Reducing the Progression of Preeclampsia

Xue-Jie-San restricts ferroptosis in Crohn's disease via inhibiting FGL1/NF-κB/STAT3 positive feedback loop

Crohn's disease (CD) is an incurable inflammatory bowel disease due to unclear etiology and pathogenesis. Accumulating evidences have shown the harmful role of ferroptosis in CD onset and development. Additionally, fibrinogen-like protein 1 (FGL1) has been verified to be a potential therapeutic target of CD. Xue-Jie-San (XJS) is an effective prescription for treating CD. However, its therapeutic mechanism has not been fully elucidated. This study aimed to determine whether XJS alleviating CD via regulating ferroptosis and FGL1 expression. A colitis rat model was induced by 2,4,6-trinitrobenzene sulfonic acid and treated with XJS. The disease activity indices of the colitis rats were scored. Histopathological damage was assessed using HE staining. ELISA was performed to examine inflammatory cytokines. Transmission electron microscopy was utilized to observe ultrastructure changes in intestinal epithelial cells (IECs). Iron load was evaluated by examining iron concentrations, the expressions of FPN, FTH and FTL. Lipid peroxidation was investigated through detecting the levels of ROS, 4-HNE, MDA and PTGS2. Furthermore, the SLC7A11/GSH/GPX4 antioxidant system and FGL1/NF-κB/STAT3 signaling pathway were examined. The results showed that colitis was dramatically ameliorated in the XJS-treated rats as evidenced by relief of clinical symptoms and histopathological damages, downregulation of pro-inflammatory cytokines IL-6, IL-17 and TNF-α, and upregulation of anti-inflammatory cytokine IL-10. Furthermore, XJS administration led to ferroptosis inhibition in IECs by reducing iron overload and lipid peroxidation. Mechanistically, XJS enhanced the SLC7A11/GSH/GPX4 antioxidant system negatively regulated by the FGL1/NF-κB/STAT3 positive feedback loop. In conclusion, XJS might restrain ferroptosis in IECs to ameliorate experimental colitis by inhibition of FGL1/NF-κB/STAT3 positive feedback loop.

Ablation of Discoidin Domain Receptor 1 Provokes an Osteopenic Phenotype by Regulating Osteoblast/Osteocyte Autophagy and Apoptosis

Discoidin domain receptor 1 (DDR1) is a collagen receptor that belongs to the receptor tyrosine kinase family. We have previously shown that DDR1 plays a crucial role during bone development, resulting in dwarfism and a short stature in osteoblast-specific knockout mice (OKO mice). However, the detailed pathophysiological effects of DDR1 on bone development throughout adulthood have remained unclear. This study aims to identify how DDR1 regulates osteoblast and osteocyte functions in vivo and in vitro during bone development in adulthood. The metabolic changes in bone tissues were analyzed using Micro-CT and immunohistochemistry staining (IHC) in vivo; the role of DDR1 in regulating osteoblasts was examined in MC3T3-E1 cells in vitro. The Micro-CT analysis results demonstrated that OKO mice showed a 10% reduction in bone-related parameters from 10 to 14 weeks old and a significant reduction in cortical thickness and diameter compared with flox/flox control mice (FF) mice. These results indicated that DDR1 knockout in OKO mice exhibiting significant bone loss provokes an osteopenic phenotype. The IHC staining revealed a significant decrease in osteogenesis-related genes, including RUNX2, osteocalcin, and osterix. We noted that DDR1 knockout significantly induced osteoblast/osteocyte apoptosis and markedly decreased autophagy activity in vivo. Additionally, the results of the gain- and loss-of-function of the DDR1 assay in MC3T3-E1 cells indicated that DDR1 can regulate the osteoblast differentiation through activating autophagy by regulating the phosphorylation of the mechanistic target of rapamycin (p-mTOR), light chain 3 (LC3), and beclin-1. In conclusion, our study highlights that the ablation of DDR1 results in cancellous bone loss by regulating osteoblast/osteocyte autophagy. These results suggest that DDR1 can act as a potential therapeutic target for managing cancellous bone loss.

Next generation of immune checkpoint molecules in maternal-fetal immunity

Successful pregnancy is a unique situation requires the maternal immune system to recognize and tolerate a semi-identical fetus and allow normal invasion of trophoblast cells. Although efforts have been made, the deep mechanisms of the maternal-fetal crosstalk have not yet been fully deciphered. Immune checkpoint molecules (ICMs) are a group of negative modulators of the immune response that avoid immune damage. They have been extensively studied in the fields of oncology and transplantation, while the latest evidence suggests that they are closely associated with pregnancy outcomes via multiple inhibitory mechanisms. Although studies have mostly demonstrated the regulatory role of the well-known PD-1, CTLA-4 at the maternal-fetal interface, what is unique about the newly discovered multiple ICMs remains a mystery. Here, we review the latest knowledge on ICMs, focusing on the first generation of checkpoints (PD-1, CTLA-4) and the next generation (Tim-3, Tigit, Lag-3, VISTA) highlighting their immunoregulatory roles in maternal-fetal tolerance and decidual vascular remodeling, and their involvement in pathological pregnancies. The content covers three aspects: the characteristics they possess, the dynamic expression profile of their expression at the maternal-fetal interface, and their involvement in pathological pregnancy. In immunotherapy strategies for pregnancy complications, upregulation of immune checkpoints may play a role. Meanwhile, the impact on pregnancy outcomes when using ICMs in clinical cancer treatment during pregnancy is a topic worth exploring. These may serve as a guide for future basic research and clinical applications of maternal-fetal immunity.