Inflammatory bowel disease (IBD), comprising Crohn’s disease and ulcerative colitis, is a refractory disease with many immune abnormalities and pathologies in the gastrointestinal tract. Because macrophages can distinguish innocuous antigens from potential pathogens to maintain mucosa barrier functions, they are essential cells in the intestinal immune system. With numerous numbers in the intestinal tract, tissue-resident macrophages have a significant effect on the constant regeneration of intestinal epithelial cells and maintaining the immune homeostasis of the intestinal mucosa. They also have a significant influence on IBD through regulating pro-(M1) or anti-inflammatory (M2) phenotype polarization according to different environmental cues. The disequilibrium of the phenotypes and functions of macrophages, disturbed by intracellular or extracellular stimuli, influences the progression of disease. Further investigation of macrophages’ role in the progression of IBD will facilitate deciphering the pathogenesis of disease and exploring novel targets to develop novel medications. In this review, we shed light on the origin and maintenance of intestinal macrophages, as well as the role of macrophages in the occurrence and development of IBD. In addition, we summarize the interaction between gut microbiota and intestinal macrophages, and the role of the macrophage-derived exosome. Furthermore, we discuss the molecular and cellular mechanisms participating in the polarization and functions of gut macrophages, the potential targeted strategies, and current clinical trials for IBD.

To identify which technique is better for avoiding biliary reflux and gastritis between uncut Roux-en-Y and Billroth II reconstruction. A total of 158 patients who underwent laparoscopy-assisted distal gastrectomy for gastric cancer at the First Hospital of Jilin University (Changchun, China) between February 2015 and February 2016 were randomized into two groups: uncut Roux-en-Y (group U) and Billroth II group (group B). Postoperative complications and relevant clinical data were compared between the two groups. According to the randomization table, each group included 79 patients. There was no significant difference in postoperative complications between groups U and B (7.6% vs 10.1%, P = 0.576). During the postoperative period, group U stomach pH values were lower than 7 and group B pH values were higher than 7. After 1 year of follow-up, group B presented a higher incidence of biliary reflux and alkaline gastritis. However, histopathology did not show a significant difference in gastritis diagnosis (P = 0.278), and the amount of residual food and gain of weight between the groups were also not significantly different. At 3 mo there was no evidence of partial recanalization of uncut staple line, but at 1 year the incidence was 13%. Compared with Billroth II reconstruction, uncut Roux-en-Y reconstruction is secure and feasible, and can effectively reduce the incidence of alkaline reflux, residual gastritis, and heartburn. Despite the incidence of recanalization, uncut Roux-en-Y should be widely applied.

Toll-like receptor 9 (TLR9) recognizes bacterial, viral and self DNA and play an important role in immunity and inflammation. However, the role of TLR9 in obesity is less well-studied. Here, we generate B-cell-specific Tlr9-deficient (Tlr9^fl/fl/Cd19Cre^+/-, KO) B6 mice and model obesity using a high-fat diet. Compared with control mice, B-cell-specific-Tlr9-deficient mice exhibited increased fat tissue inflammation, weight gain, and impaired glucose and insulin tolerance. Furthermore, the frequencies of IL-10-producing-B cells and marginal zone B cells were reduced, and those of follicular and germinal center B cells were increased. This was associated with increased frequencies of IFNγ-producing-T cells and increased follicular helper cells. In addition, gut microbiota from the KO mice induced a pro-inflammatory state leading to immunological and metabolic dysregulation when transferred to germ-free mice. Using 16 S rRNA gene sequencing, we identify altered gut microbial communities including reduced Lachnospiraceae, which may play a role in altered metabolism in KO mice. We identify an important network involving Tlr9, Irf4 and Il-10 interconnecting metabolic homeostasis, with the function of B and T cells, and gut microbiota in obesity.

The five-year survival rate of patients with colorectal cancer (CRC) liver metastasis is less than 30 %, and chemotherapy resistance and metastatic microenvironment remodeling are the current treatment bottlenecks. Cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) form a “CRCs-CAFs crosstalk” with colorectal cancer cells (CRCs) by secreting dense extracellular matrix (ECM), free fatty acids (FFA), and pro-metastatic factors, driving a vicious cycle of drug resistance and metastasis. During liver metastasis, hepatic stellate cells (HSCs)-derived CAFs (HSC-CAFs) promote tumor metastasis by remodeling the pre-metastatic microenvironment. Based on clinical sample RNA sequencing and mouse single-cell sequencing to reveal ECM signal enrichment and CAFs activation characteristics, we innovatively constructed a nano-delivery system using hyaluronic acid-modified MIL-100 nanoparticles (OEMH NPs) co-loaded with oxaliplatin (OXA) and epigallocatechin gallate (EGCG). This system can target the CRCs-CAFs crosstalk through CD44 receptor: on the one hand, OEMH NPs can inhibit CAFs activation and reduce ECM deposition, improve drug penetration and down-regulate FFA metabolic reprogramming, reverse OXA resistance; on the other hand, OEMH NPs can block the transformation of HSCs to CAFs, down-regulate pro-metastatic factors such as VEGF/IL-11/ANG, induce vascular normalization, and reprogram the pre-metastatic microenvironment. This strategy can simultaneously achieve primary lesion drug sensitization and liver metastasis inhibition, providing a new paradigm for the treatment of advanced colorectal cancer to break through the traditional treatment dilemma through dual reprogramming of metabolism and microenvironment, and has significant clinical translation potential.