Inflammation primarily influences the initiation, progression, and deterioration of many human diseases, and immune cells are the principal forces that modulate the balance of inflammation by generating cytokines and chemokines to maintain physiological homeostasis or accelerate disease development. S100A8/A9, a heterodimer protein mainly generated by neutrophils, triggers many signal transduction pathways to mediate microtubule constitution and pathogen defense, as well as intricate procedures of cancer growth, metastasis, drug resistance, and prognosis. Its paired receptors, such as receptor for advanced glycation ends (RAGEs) and toll-like receptor 4 (TLR4), also have roles and effects within tumor cells, mainly involved with mitogen-activated protein kinases (MAPKs), NF-κB, phosphoinositide 3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR) and protein kinase C (PKC) activation. In the clinical setting, S100A8/A9 and its receptors can be used complementarily as efficient biomarkers for cancer diagnosis and treatment. This review comprehensively summarizes the biological functions of S100A8/A9 and its various receptors in tumor cells, in order to provide new insights and strategies targeting S100A8/A9 to promote novel diagnostic and therapeutic methods in cancers.

Nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) plays an important role in the regulation of glucose homeostasis and lipid metabolism. However, current PPARγ-targeting drugs such as thiazolidinediones (TZDs) are associated with undesirable side effects. We identified a small molecular compound, F12016, as a selective PPARγ agonist by virtual screening, which showed moderate PPARγ agonistic activity and binding ability for PPARγ. F12016 did not activate other PPAR subtypes at 30 μM and selectively modulated PPARγ target gene expression. In diabetic KKAy mice, F12016 had insulin-sensitizing and glucose-lowering properties and suppressed weight gain. In vitro, F12016 effectively increased glucose uptake and blocked cyclin-dependent kinase 5-mediated phosphorylation of PPARγ at Ser273, but slightly triggered adipogenesis and less inhibited osteoblastogenesis than rosiglitazone. Moreover, compared with the full agonist rosiglitazone, F12016 had a distinct group of coregulators and a different predicted binding mode for the PPARγ ligand-binding domain. A site mutation assay confirmed the key epitopes, especially Tyr473 in AF-2. In summary, our study shows that F12016 is a non-TZD, novel selective PPARγ agonist without the classical lipogenic side effects, which may provide a new structural strategy for designing PPARγ ligands with advantages over TZDs.

Breast cancer (BC) is one of the most common malignant tumors in women globally, and its occurrence has surpassed lung cancer and become the biggest threat for women. At present, breast cancer treatment includes surgical resection or postoperative chemotherapy and radiotherapy. However, tumor relapse and metastasis usually lead to current therapy failure thanks to breast cancer stem cells (BCSCs)-mediated tumorigenicity and drug resistance. Drug resistance is mainly due to the long-term quiescent G0 phase, strong DNA repairability, and high expression of ABC transporter, and the tumorigenicity is reflected in the activation of various proliferation pathways related to BCSCs. Therefore, understanding the characteristics of BCSCs and their intracellular and extracellular molecular mechanisms is crucial for the development of targeted drugs for BCSCs. To this end, we discussed the latest developments in BCSCs research, focusing on the analysis of specific markers, critical signaling pathways that maintain the stemness of BCSCs，such as NOTCH, Wnt/β-catenin, STAT3, Hedgehog, and Hippo-YAP signaling, immunomicroenviroment and summarizes targeting therapy strategies for stemness maintenance and differentiation, which provides a theoretical basis for further exploration of treating breast cancer and preventing relapse derived from BCSCs.

Atherosclerosis is a chronic disease characterized by lipid deposition and inflammatory response. NOD‐, LRR‐ and pyrin domain‐containing protein 3 (NLRP3) inflammasome‐facilitated inflammatory responses are crucial in the pathogenesis of atherosclerosis, and thus new therapeutic approaches are emerging that target NLRP3 and inflammation. Here, we explored the anti‐atherosclerotic effect and mechanisms of a new rutaecarpine derivative, 5‐deoxy‐rutaecarpine (R3) in vitro and in vivo. R3 treatment attenuated atherosclerosis development and increased plaque stability in Apoe ^−/− mice fed a high‐fat diet, and decreased levels of inflammatory mediators, such as interleukin‐1β, in the serum of Apoe ^−/− mice and in oxidized low‐density lipoprotein (ox‐LDL)‐stimulated murine macrophages. R3 treatment inhibited NLRP3 inflammasome activation in the livers of Apoe ^−/− mice and ox‐LDL‐stimulated murine macrophages by inhibiting NF‐κB and MAPK pathways. Additionally, R3 significantly decreased total cholesterol in the serum and livers of Apoe ^−/− mice and promoted cholesterol efflux in murine macrophages through upregulating protein expression of ATP‐binding cassette subfamily A member 1 and scavenger receptor class B type I/human CD36 and lysosomal integral membrane protein‐II analogous‐1. Our results demonstrated that R3 prevented atherosclerotic progression via attenuating NLRP3 inflammasome‐related inflammation and modulating cholesterol transport.

BACKGROUND: Atherosclerosis is the most common cause of cardiovascular diseases. Clinical studies indicate that loss-of-function ASGR1 (asialoglycoprotein receptor 1) is significantly associated with lower plasma cholesterol levels and reduces cardiovascular disease risk. However, the effect of ASGR1 on atherosclerosis remains incompletely understood; whether inhibition of ASGR1 causes liver injury remains controversial. Here, we comprehensively investigated the effects and the underlying molecular mechanisms of ASGR1 deficiency and overexpression on atherosclerosis and liver injury in mice. METHODS: We engineered Asgr1 knockout mice ( Asgr1 ^−/− ), Asgr1 and ApoE double-knockout mice ( Asgr1 ^−/− ApoE ^−/− ), and ASGR1-overexpressing mice on an ApoE ^−/− background and then fed them different diets to assess the role of ASGR1 in atherosclerosis and liver injury. RESULTS: After being fed a Western diet for 12 weeks, Asgr1 ^−/− ApoE ^−/− mice exhibited significantly decreased atherosclerotic lesion areas in the aorta and aortic root sections, reduced plasma VLDL (very-low-density lipoprotein) cholesterol and LDL (low-density lipoprotein) cholesterol levels, decreased VLDL production, and increased fecal cholesterol contents. Conversely, ASGR1 overexpression in ApoE ^−/− mice increased atherosclerotic lesions in the aorta and aortic root sections, augmented plasma VLDL cholesterol and LDL cholesterol levels and VLDL production, and decreased fecal cholesterol contents. Mechanistically, ASGR1 deficiency reduced VLDL production by inhibiting the expression of MTTP (microsomal triglyceride transfer protein) and ANGPTL3 (angiopoietin-like protein 3)/ANGPTL8 (angiopoietin-like protein 8) but increasing LPL (lipoprotein lipase) activity, increased LDL uptake by increasing LDLR (LDL receptor) expression, and promoted cholesterol efflux through increasing expression of LXRα (liver X receptor-α), ABCA1 (ATP-binding cassette subfamily A member 1), ABCG5 (ATP-binding cassette subfamily G member 5), and CYP7A1 (cytochrome P450 family 7 subfamily A member 1). These underlying alterations were confirmed in ASGR1-overexpressing ApoE ^−/− mice. In addition, ASGR1 deficiency exacerbates liver injury in Western diet–induced Asgr1 ^−/− ApoE ^−/− mice and high-fat diet–induced but not normal laboratory diet–induced and high-fat and high-cholesterol diet–induced Asgr1 ^−/− mice, while its overexpression mitigates liver injury in Western diet–induced ASGR1-overexpressing ApoE ^−/− mice. CONCLUSIONS: Inhibition of ASGR1 inhibits atherosclerosis in Western diet–fed ApoE ^−/− mice, suggesting that inhibiting ASGR1 may serve as a novel therapeutic strategy to treat atherosclerosis and cardiovascular diseases.