CCL7 playing a dominant role in recruiting early OCPs to facilitate osteolysis at metastatic site of colorectal cancer

Adaptive selection of quasispecies during in vivo passaging in chickens, mice, and ferrets results in host-specific strains for the H9N2 avian influenza virus

Sporadic human infections of avian influenza virus (AIV) raise significant public health concerns. A critical factor limiting the transmission of AIVs is the shift in receptor-binding preference from Siaα2,3 to Siaα2,6. To reveal the adaptive selection dynamics during the host adaptation process of AIVs, this study generated a viral library with random mutations in the HA gene of the H9N2 strain. Upon passaging the viral library in chickens and mice, the predominantly selected variants exhibited a preference for Siaα2,3 receptors. Notably, the wild-type strain remained dominant in both inoculated and direct-contact chickens, while variants with the ΔL226/R229I substitutions were preferentially selected in mice. Ferrets have a predominance of Siaα2,6 in their respiratory tract. As expected, the variant harboring the N289D mutation, which prefers Siaα2,6 binding, was enriched during in vivo passaging in ferrets. The mice-adapted variant with the ΔL226/R229I mutations causes reduced levels of TNF-α in the early days post-infection in mice, which correlated with an increase in its viral titers. Conversely, elevated levels of IL-6 and IL-1β at five dpi may contribute to the development of the cytokine release syndrome, potentially elucidating the higher fatality rate observed. In conclusion, based on the mutant spectra of the HA gene, this study elucidates the distinct quasispecies dynamics during the adaptation of H9N2 to different hosts, with receptor availability serving as one of the driving factors. Furthermore, a series of critical substitutions that influence the interspecific transmission potential of H9N2 AIVs were identified.IMPORTANCEThe mutation of viruses creates a quasispecies reservoir. In this study, we aimed to investigate the dynamics of quasispecies during the host adaptation of AIVs. We generated a viral library with random mutations in the HA gene of H9N2 and conducted serial passaging in chickens, mice, and ferrets for five generations, respectively. The wild-type strain was dominant in chickens, while mice selected viruses with the ΔL226/R229I substitutions. Both variants showed a preference for binding to Siaα2,3, which aligned with the abundance of Siaα2,3 found in the respiratory tract epithelial cells of chickens and mice. In ferrets, where Siaα2,6 is more prevalent, the variant with the N289D mutation, which prefers Siaα2,6, was found to be enriched. In summary, this study revealed the adaptive selection of H9N2 quasispecies in various hosts, contributing to our understanding of AIV host adaptation.

CCL7 promotes macrophage polarization and synovitis to exacerbate rheumatoid arthritis

Chemokine C-C motif ligand 7 (CCL7) is implicated in various immune and inflammatory processes; however, its role in rheumatoid arthritis (RA) remains unclear. In this study, we observed that CCL7 expression was upregulated in synovial M1-polarized macrophages and in the serum of RA mice and patients. CCL7 was found to promote macrophage polarization toward the M1 phenotype while inhibiting M2 differentiation in vitro. Furthermore, intra-articular injection of recombinant CCL7 protein in mice resulted in enhanced M1 polarization, increased inflammation, and fibrosis within synovial tissues, which exacerbated arthritis-associated pain. These effects were partially mitigated by treatment with a CCL7 neutralizing antibody. Mechanistically, we identified a CCL7 autocrine positive feedback loop that amplifies inflammation via the CCL7-CCR1-JAK2/STAT1 pathway. Collectively, our findings reveal a previously unrecognized CCL7-mediated autocrine inflammatory amplification loop that modulates macrophage polarization and exacerbates RA progression, positioning CCL7 as a potential therapeutic target for RA.

Lactate modulates microglial inflammatory responses through HIF-1α-mediated CCL7 signaling after cerebral ischemia in mice

Lactate is a potent regulator of neuroinflammation. We recently demonstrated that lactate alleviated neuronal injury via HIF-1α-regulated microglial inflammation after oxygen-glucose deprivation (OGD). However, the underlying mechanisms and the effect of lactate on microglial responses after ischemic stroke remained unknown. Mouse acute cerebral ischemia-reperfusion injury was induced by middle cerebral artery occlusion (MCAO). L-lactate (100 mM, 2 μl) was intracerebroventricularly administrated 30 min after the reperfusion. Microglia responses were evidenced by the expression of multiple markers such as CD86, iNOS, arginase-1, CD206 and Ym1 in the peri-infarction 24 h after MCAO using western blot analysis and quantitative real-time PCR. Inflammatory factors IL-6, TNF-α, TGF-β and IL-10, as well as NF-κB signaling were also detected. Infarct size and neuronal apoptosis in the peri-infarction at 24 h, mice survival within 7 days and long-term neurobehavioral function were evaluated. The involvement of HIF-1α in lactate-mediated microglial inflammation after MCAO was assessed using a HIF-1α inhibitor. Additionally, transcriptome analysis was used to identify the potential lactate targets in BV2 cells after OGD. The recombinant product of the identified CCL7 gene was used to verify its effect on cerebral ischemia-reperfusion injury in vivo. Lactate supplementation reduced infarction volume, neuronal apoptosis and neurological deficits. Lactate reduced the expression of CD86, iNOS, IL-6, TNF-α and elevated the expression of arginase-1, CD206, Ym1, TGF-β and IL-10 in the peri-infarction at 24 h after reperfusion. Consistently, lactate inhibited the NF-κB signaling. Additionally, lactate upregulated HIF-1α in microglia 24 h after reperfusion, while inhibition of HIF-1α reversed the effects of lactate on brain damage and neuroinflammation after cerebral ischemia. Furthermore, CCL7 was identified as the top down-regulated inflammatory gene induced by lactate in OGD-treated BV2 cells. It was also found high expression of CCL7 in the peri-infarction at 24 h after reperfusion and lactate treatment inhibited CCL7 expression. However, HIF-1α inhibitor reversed the effect of lactate treatment on CCL7 expression. Finally, supplementation of recombinant CCL7 reversed the mitigated neuroinflammation and neuroprotective effect rendered by lactate treatment after MCAO. We concluded that treatment with lactate modulated the microglia inflammatory responses and alleviated cerebral ischemia injury. The inhibition of CCL7/NF-κB signaling by HIF-1α might be involved in the beneficial effect of lactate treatment.

Investigating the pharmacological mechanism of Zhengyuan jiaonang for treating colorectal cancer via network pharmacology analysis and experimental verification

ETHNOPHARMACOLOGICAL RELEVANCE

Zhengyuan jiaonang (ZYJN) is a traditional Chinese patent medicine (CPM) used in China for adjuvant cancer therapy, which has been proved to have anti-fatigue effects.

AIM OF STUDY

The study aims to investigate the antitumor effects of ZYJN and its underlying mechanisms using subcutaneous transplant CT26 model.

MATERIALS AND METHODS

Fingerprint analysis of ZYJN was performed using high performance liquid chromatography. The potential targets of ZYJN were predicted using bioinformatic analysis, which were further validated by Western Blot assay. Subcutaneous transplant CT26 model was used to evaluate the antitumor effects of ZYJN. The effects of ZYJN on the tumor immune microenvironment were investigated by flow cytometry. Transparent imaging was used to investigate the effects of ZYJN on fibrosis and angiogenesis.

RESULTS

ZYJN could inhibit colorectal cancer growth when administered alone or in combination with 5-FU. The combination of ZYJN and 5-FU could significantly increase the serum level of albumin (ALB) and decrease the serum level of aspartate aminotransferase (AST). In addition, the combination of ZYJN at 0.75 g/kg and 5-FU significantly decreased the serum level of vascular endothelial growth factors (VEGF) and inhibited the angiogenesis of CT26 cancer. The combination of ZYJN at 1.50 g/kg and 5-FU could promote the fibrosis process of CT26 cancer. Additionally, combination of ZYJN and 5-FU could significantly increase the percentage of tumor-infiltrating T cells and CD4+ T cells in the late stage of CT26 model, while ZYJN at 1.50 g/kg increased the percentage of NK cells as well as CD8+ T cells in the early stage of CT26 model. Western Blot analysis revealed that administration of ZYJN at 0.75 g/kg reduced the expression of PI3K-p110α, CDK1, CCNB1 and MMP-9, and inhibited the phosphorylation of Akt (Thr308).

CONCLUSIONS

ZYJN could inhibit the tumor growth of CT26 colorectal cancer by promoting tumor fibrosis, suppressing angiogenesis, migration, and invasion and modulating the tumor immune microenvironment. ZYJN enhanced the efficacy and reduced the toxicity of chemotherapy drugs in combination therapy. Our findings provide evidence for the clinical application of ZYJN in cancer treatment.

Chemokines: Function and therapeutic potential in bone metastasis of lung cancer

Lung cancer is a rapidly progressing disease with a poor prognosis. Bone metastasis is commonly found in 40.6% of advanced-stage patients. The mortality rate of lung cancer patients with bone metastasis can be significantly decreased by implementing novel diagnostic techniques, improved staging and classification systems, precise surgical interventions, and advanced treatment modalities. However, it is important to note that there is currently a lack of radical procedures available for these patients due to the development of drug resistance. Consequently, palliative care approaches are commonly employed in clinical practice. Therefore, new understandings of the process of bone metastasis of lung cancer are critical for developing better treatment strategies to improve patient's clinical cure rate and quality of life. Chemokines are cell-secreted small signaling proteins in cancer occurrence, proliferation, invasion, and metastasis. In this study, we review the development of bone metastasis in lung cancer and discuss the mechanisms of specific chemokine families (CC, CXC, CX3C, and XC) in regulating the biological activities of tumors and promoting bone metastasis. We also highlight some preclinical studies and clinical trials on chemokines for lung cancer and bone metastasis.