Bone-metastatic lung adenocarcinoma cells bearing CD74-ROS1 fusion interact with macrophages to promote their dissemination.

Approximately 40% of patients with lung adenocarcinoma (LUAD) often develop bone metastases during the course of their disease. However, scarcely any in vivo model of LUAD bone metastasis has been established, leading to a poor understanding of the mechanisms underlying LUAD bone metastasis. Here, we established a multiorgan metastasis model via the left ventricular injection of luciferase-labeled LUAD cells into nude mice and then screened out lung metastasis (LuM) and bone metastasis (BoM) cell subpopulations. BoM cells exhibited greater stemness and epithelial-mesenchymal transition (EMT) plasticity than LuM cells and initially colonized the bone and subsequently disseminated to distant organs after being reinjected into mice. Moreover, a CD74-ROS1 fusion mutation (C6; R34) was detected in BoM cells but not in LuM cells. Mechanistically, BoM cells bearing the CD74-ROS1 fusion highly secrete the C-C motif chemokine ligand 5 (CCL5) protein by activating STAT3 signaling, recruiting macrophages in tumor microenvironment and strongly inducing M2 polarization of macrophages. BoM cell-activated macrophages produce a high level of TGF-ß1, thereby facilitating EMT and invasion of LUAD cells via TGF-ß/SMAD2/3 signaling. Targeting the CD74-ROS1/CCL5 axis with Crizotinib (a ROS1 inhibitor) and Maraviroc (a CCL5 receptor inhibitor) in vivo strongly impeded bone metastasis and secondary metastasis of BoM cells. Our findings reveal the critical role of the CD74-ROS1/STAT3/CCL5 axis in the interaction between LUAD bone metastasis cells and macrophages for controlling LUAD cell dissemination, highlighting the significance of the bone microenvironment in LUAD bone metastasis and multiorgan secondary metastasis, and suggesting that targeting CD74-ROS1 and CCL5 is a promising therapeutic strategy for LUAD bone metastasis.

Exploring the Diagnostic and Prognostic Significance of Alkaline Phosphatase on Neutrophil Surface Membrane in Patients with Sepsis.

Background: Sepsis, characterized by life-threatening organ dysfunction, stems from an unregulated host response. Timely identification is pivotal for enhancing the prognosis of sepsis patients. Objective: This study aims to explore the diagnostic and prognostic values of alkaline phosphatase on the surface membrane of neutrophils (mNAP) in peripheral blood among sepsis patients. Design: The study employed a retrospective design. Setting: This study was conducted at Donghai County People's Hospital. Participants: A total of 180 sepsis patients were selected and categorized into the sepsis shock group (n=45) and the sepsis non-shock group (n=135). Additionally, 35 patients with non-infectious systemic inflammatory response syndrome served as the control group. Interventions: mNAP was assessed via flow cytometry, while serum procalcitonin (PCT) and C-reactive protein (CRP) levels were measured through immunoassay. Primary Outcome Measures: (1) Changes in mNAP, PCT, and CRP. (2) Correlation of mNAP with CRP and PCT in sepsis patients. (3) Diagnostic values of mNAP, PCT, and CRP in sepsis. Results: Statistically significant differences in mNAP, PCT, and CRP were observed between the sepsis shock group, the sepsis non-shock group, and the control group (P = .000). The median value of mNAP (22627 Ab/c) in the 28-day death group was significantly higher than that (5100 Ab/c) in the survival group (P = .000). Spearman rank correlation analysis indicated a positive correlation between mNAP, PCT, and CRP in sepsis patients (P < .01). Conclusions: Both mNAP and PCT exhibit superior diagnostic specificity and sensitivity compared to CRP. While mNAP demonstrates similar sensitivity to PCT in diagnosing sepsis, its diagnostic specificity surpasses that of PCT. mNAP holds promise as a novel marker for the diagnosis and prognosis of sepsis.

P4HA2 activates mTOR via hydroxylation and targeting P4HA2-mTOR inhibits lung adenocarcinoma cell growth.

Mammalian target of rapamycin (mTOR) kinase functions as a central regulator of cell growth and metabolism, and its complexes mTORC1 and mTORC2 phosphorylate distinct substrates. Dysregulation of mTOR signaling is commonly implicated in human diseases, including cancer. Despite three decades of active research in mTOR, much remains to be determined. Here, we demonstrate that prolyl 4-hydroxylase alpha-2 (P4HA2) binds directly to mTOR and hydroxylates one highly conserved proline 2341 (P2341) within a kinase domain of mTOR, thereby activating mTOR kinase and downstream effector proteins (e.g. S6K and AKT). Moreover, the hydroxylation of P2341 strengthens mTOR stability and allows mTOR to accurately recognize its substrates such as S6K and AKT. The growth of lung adenocarcinoma cells overexpressing mTORP2341A is significantly reduced when compared with that of cells overexpressing mTORWT. Interestingly, in vivo cell growth assays show that targeting P4HA2-mTOR significantly suppresses lung adenocarcinoma cell growth. In summary, our study reveals an undiscovered hydroxylation-regulatory mechanism by which P4HA2 directly activates mTOR kinase, providing insights for therapeutically targeting mTOR kinase-driven cancers.

The gut metabolite indole-3-propionic acid activates ERK1 to restore social function and hippocampal inhibitory synaptic transmission in a 16p11.2 microdeletion mouse model.

BACKGROUND: Microdeletion of the human chromosomal region 16p11.2 (16p11.2 + / - ) is a prevalent genetic factor associated with autism spectrum disorder (ASD) and other neurodevelopmental disorders. However its pathogenic mechanism remains unclear, and effective treatments for 16p11.2 + / -  syndrome are lacking. Emerging evidence suggests that the gut microbiota and its metabolites are inextricably linked to host behavior through the gut-brain axis and are therefore implicated in ASD development. Despite this, the functional roles of microbial metabolites in the context of 16p11.2 + / -  are yet to be elucidated. This study aims to investigate the therapeutic potential of indole-3-propionic acid (IPA), a gut microbiota metabolite, in addressing behavioral and neural deficits associated with 16p11.2 + / - , as well as the underlying molecular mechanisms. RESULTS: Mice with the 16p11.2 + / -  showed dysbiosis of the gut microbiota and a significant decrease in IPA levels in feces and blood circulation. Further, these mice exhibited significant social and cognitive memory impairments, along with hyperactivation of hippocampal dentate gyrus neurons and reduced inhibitory synaptic transmission in this region. However, oral administration of IPA effectively mitigated the histological and electrophysiological alterations, thereby ameliorating the social and cognitive deficits of the mice. Remarkably, IPA treatment significantly increased the phosphorylation level of ERK1, a protein encoded by the Mapk3 gene in the 16p11.2 region, without affecting the transcription and translation of the Mapk3 gene. CONCLUSIONS: Our study reveals that 16p11.2 + / -  leads to a decline in gut metabolite IPA levels; however, IPA supplementation notably reverses the behavioral and neural phenotypes of 16p11.2 + / -  mice. These findings provide new insights into the critical role of gut microbial metabolites in ASD pathogenesis and present a promising treatment strategy for social and cognitive memory deficit disorders, such as 16p11.2 microdeletion syndrome. Video Abstract.

Novel putative pathogenic viruses identified in pangolins by mining metagenomic data.

The pangolin is the only scaly mammal in the world and also an important reservoir of pathogenic viruses. Habitat loss and poaching have been shrinking the survival range of pangolins. More information on pangolin virus populations is needed to better understand and assess potential disease risks. In this study, viral metagenomic data were used to reinvestigate the virome in pangolin lung tissue. Complete genome sequences of two novel anelloviruses were acquired and clustered with the referenced feline strains belonging to genus Tettorquevirus and genus Etatorquevirus, respectively. Two genomes belonging to the genus Gemykibivirus, and species Bat-associated cyclovirus 9 were detected, respectively. One genome with a large contig belonging to the genus Senecavirus were also characterized, according to phylogenetic analysis, which can be presumed to be a novel species. In addition, a full genome of endogenous retroviruse (ERV) was assembled from the lungs of pangolin, and this virus may have the possibility of cross-species transmission during the evolution. This virological investigation has increased our understanding of the virome carried by pangolins and provided a reference baseline for possible zoonotic infectious diseases in the future.

Temporal changes in Egr-1 and c-fos expression in rat models of myocardial ischemia.

BACKGROUND: The pathological diagnosis of sudden cardiac death caused by myocardial ischemia is a difficult problem. Relevant evidence shows that the expression of Egr-1 and c-fos undergo changes in the early stage of myocardial ischemia, but the detailed temporal variation of them is not clear. Therefore, the aim of this study was to observe the temporal changes in mRNA and protein expression of Egr-1 and c-fos in ischemic myocardium in rats. METHODS: Sixty-six Sprague-Dawley rats were divided into the control group, the early myocardial ischemia (EMI) group, the sham operated group and the allergy group. The EMI rats were further divided into eight subgroups according to the different time points (30 min and 1, 2, 4, 8, 12, 24, and 48 h) after modeling. The mRNA and protein of Egr-1 and c-fos of each group were detected by real-time quantitative polymerase chain reaction and immunohistochemistry, respectively. RESULTS: In the EMI group, Egr-1 mRNA in ischemic myocardium rose 30 min after ischemia and peaked at 2 h; the plateau was maintained up to 8 h after ischemia, and then returned to the baseline level at 12 h. The c-fos mRNA in ischemic myocardium demonstrated a consistent changing curve with that of Egr-1. The mRNA of Egr-1 and c-fos showed no significant changes in the control group, the sham operated group and the allergy group. Immunohistochemistry showed that Egr-1 protein in the myocardial ischemic area was slightly positive 30 min after ischemia, and then strongly positive at 4 and 8 h, decreased at 12 h, and was negative at 24 h. The changing trends of c-fos protein were almost the same as that of Egr-1. Immunohistochemistry of Egr-1 and c-fos protein were all negative in the control group, the sham operated group and the allergy group. CONCLUSIONS: The mRNA and protein expression of Egr-1 and c-fos presented rapid and temporal changes after myocardial ischemia, and this may be helpful in distinguishing sudden death induced by myocardial ischemia from that of allergy.