Cytokine-induced neutrophil mobilization from the bone marrow to circulation is a critical event in acute inflammation, but how it is accurately controlled remains poorly understood. In this study, we report that CXCR2 ligands are responsible for rapid neutrophil mobilization during early-stage acute inflammation. Nevertheless, although serum CXCR2 ligand concentrations increased during inflammation, neutrophil mobilization slowed after an initial acute fast phase, suggesting a suppression of neutrophil response to CXCR2 ligands after the acute phase. We demonstrate that granulocyte colony-stimulating factor (G-CSF), usually considered a prototypical neutrophil-mobilizing cytokine, was expressed later in the acute inflammatory response and unexpectedly impeded CXCR2-induced neutrophil mobilization by negatively regulating CXCR2-mediated intracellular signaling. Blocking G-CSF in vivo paradoxically elevated peripheral blood neutrophil counts in mice injected intraperitoneally with Escherichia coli and sequestered large numbers of neutrophils in the lungs, leading to sterile pulmonary inflammation. In a lipopolysaccharide-induced acute lung injury model, the homeostatic imbalance caused by G-CSF blockade enhanced neutrophil accumulation, edema, and inflammation in the lungs and ultimately led to significant lung damage. Thus, physiologically produced G-CSF not only acts as a neutrophil mobilizer at the relatively late stage of acute inflammation, but also prevents exaggerated neutrophil mobilization and the associated inflammation-induced tissue damage during early-phase infection and inflammation.

Obesity is a global health threat. Herein, we evaluated the underlying mechanism of anti-obese features of bitter orange (Citrus aurantium Linné, CA). Eight-week-administration of CA in high fat diet-induced obese C57BL/6 mice resulted in a significant decrease of body weight, adipose tissue weight and serum cholesterol. In further in vitro studies, we observed decreased lipid droplets in CA-treated 3T3-L1 adipocytes. Suppressed peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein alpha indicated CA-inhibited adipogenesis. Moreover, CA-treated primary cultured brown adipocytes displayed increased differentiation associated with elevation of thermogenic factors including uncoupling protein 1 and PPARγ coactivator 1 alpha as well. The effects of CA in both adipocytes were abolished in AMP-activated protein kinase alpha (AMPKα)-suppressed environments, suggesting the anti-adipogenic and pro-thermogenic actions of CA were dependent on AMPKα pathway. In conclusion, our results suggest CA as a potential anti-obese agent which regulates adipogenesis and thermogenesis via AMPKα.

Both microbial infection and sterile inflammation augment bone marrow (BM) neutrophil production, but whether the induced accelerated granulopoiesis is mediated by a common pathway and the nature of such a pathway are poorly defined. We recently established that BM myeloid cell–derived reactive oxygen species (ROS) externally regulate myeloid progenitor proliferation and differentiation in bacteria-elicited emergency granulopoiesis. In this article, we show that BM ROS levels are also elevated during sterile inflammation. Similar to in microbial infection, ROS were mainly generated by the phagocytic NADPH oxidase in Gr1⁺ myeloid cells. The myeloid cells and their ROS were uniformly distributed in the BM when visualized by multiphoton intravital microscopy, and ROS production was both required and sufficient for sterile inflammation–elicited reactive granulopoiesis. Elevated granulopoiesis was mediated by ROS-induced phosphatase and tensin homolog oxidation and deactivation, leading to upregulated PtdIns(3,4,5)P3 signaling and increased progenitor cell proliferation. Collectively, these results demonstrate that, although infection-induced emergency granulopoiesis and sterile inflammation–elicited reactive granulopoiesis are triggered by different stimuli and are mediated by distinct upstream signals, the pathways converge to NADPH oxidase–dependent ROS production by BM myeloid cells. Thus, BM Gr1⁺ myeloid cells represent a key hematopoietic niche that supports accelerated granulopoiesis in infective and sterile inflammation. This niche may be an excellent target in various immune-mediated pathologies or immune reconstitution after BM transplantation.

Obesity is known to be associated with risk and aggressiveness of cancer. Melanoma, the most lethal type of skin cancer, is also closely related to the prevalence of obesity. In this study, we established a cancer–obesity comorbidity (COC) model to investigate the effects of vanillic acid (VA). After a five-week administration with a high-fat diet (HFD) to induce obesity, subcutaneous allograft of B16BL6 cells were followed, and VA was orally administrated for an additional two weeks. VA-fed mice showed significantly decreased body weight and white adipose tissue (WAT) weight, which were due to increased thermogenesis and AMPK activation in WATs. Growth of cancer was also suppressed. Mechanistic studies revealed increased apoptosis and autophagy markers by VA; however, caspase 3 was not involved. Since signal transducer and activator of transcription 3 (STAT3) is suggested as an important pathway linking obesity and cancer, we further investigated to find out if STAT3 phosphorylation was repressed by VA treatment, and this was again confirmed in a COC cell model of adipocyte conditioned medium-treated B16BL6 melanoma cells. Overall, our results show VA induces STAT3-mediated autophagy to inhibit cancer growth and thermogenesis to ameliorate obesity in COC. Based on these findings, we suggest VA as a candidate therapeutic agent for COC treatment.

Panax ginseng C.A. Meyer, a widely used traditional medicine in East Asia, shows many beneficial effects on immune function, male erectile dysfunction, cancer, excessive oxidants, and aging issues. However, its effect on benign prostatic hyperplasia (BPH) and its potential in the treatment of side effects related to finasteride (Fi), an FDA-approved drug for BPH, are less known. This study aimed to verify the therapeutic effects of a water extract of P. ginseng (PGWE) on BPH in testosterone propionate (TP)-induced BPH rats and TP-treated RWPE-1 human epithelial cells, and the inhibitory potential on the Fi-induced side effects is also explored. In the TP-induced BPH rat model, PGWE alleviated the pathological markers of BPH such as weight and epithelial thickness of the prostate, and the serum level of dihydrotestosterone. PGWE downregulated androgen-related BPH factors such as 5α-reductase 2 and androgen receptor. PGWE also showed prostatic cell apoptosis accompanied by increased expression of Bax and decreased expression of Bcl-xL and cleaved-caspase 3, respectively, in addition to increasing mitochondrial dynamics in both in vivo and in vitro BPH models. Notably, reduced sperm count, one of the serious side effects of Fi, in the epididymis of BPH rats was recovered with PGWE treatment, suggesting less toxicity to sperm development by PGWE. PGWE also protected against Fi-induced sperm loss when PGWE was administered in combination with Fi without compromising the therapeutic effects of Fi on BPH. Based on these findings, we propose that PGWE could be an alternative therapeutic agent for BPH.