The kinase complex mTORC2 promotes the longevity of virus-specific memory CD4+ T cells by preventing ferroptosis.

Antigen-specific memory CD4+ T cells can persist and confer rapid and efficient protection from microbial reinfection. However, the mechanisms underlying the long-term maintenance of the memory CD4+ T cell pool remain largely unknown. Here, using a mouse model of acute infection with lymphocytic choriomeningitis virus (LCMV), we found that the serine/threonine kinase complex mammalian target of rapamycin complex 2 (mTORC2) is critical for the long-term persistence of virus-specific memory CD4+ T cells. The perturbation of mTORC2 signaling at memory phase led to an enormous loss of virus-specific memory CD4+ T cells by a unique form of regulated cell death (RCD), ferroptosis. Mechanistically, mTORC2 inactivation resulted in the impaired phosphorylation of downstream AKT and GSK3ß kinases, which induced aberrant mitochondrial reactive oxygen species (ROS) accumulation and ensuing ferroptosis-causative lipid peroxidation in virus-specific memory CD4+ T cells; furthermore, the disruption of this signaling cascade also inhibited glutathione peroxidase 4 (GPX4), a major scavenger of lipid peroxidation. Thus, the mTORC2-AKT-GSK3ß axis functions as a key signaling hub to promote the longevity of virus-specific memory CD4+ T cells by preventing ferroptosis.

Impressic Acid Attenuates the Lipopolysaccharide-Induced Inflammatory Response by Activating the AMPK/GSK3ß/Nrf2 Axis in RAW264.7 Macrophages.

Inflammatory diseases are caused by excessive inflammation from pro-inflammatory mediators and cytokines produced by macrophages. The Nrf2 signaling pathway protects against inflammatory diseases by inhibiting excessive inflammation via the regulation of antioxidant enzymes, including HO-1 and NQO1. We investigated the anti-inflammatory effect of impressic acid (IPA) isolated from Acanthopanax koreanum on the lipopolysaccharide (LPS)-induced inflammation and the underlying molecular mechanisms in RAW264.7 cells. IPA attenuated the LPS-induced production of pro-inflammatory cytokines and reactive oxygen species, and the activation of the NF-κB signaling pathway. IPA also increased the protein levels of Nrf2, HO-1, and NQO1 by phosphorylating CaMKKß, AMPK, and GSK3ß. Furthermore, ML385, an Nrf2 inhibitor, reversed the inhibitory effect of IPA on LPS-induced production of pro-inflammatory cytokines in RAW264.7 cells. Therefore, IPA exerts an anti-inflammatory effect via the AMPK/GSK3ß/Nrf2 signaling pathway in macrophages. Taken together, the findings suggest that IPA has preventive potential for inflammation-related diseases.

Development of an immunogenomic landscape for the competing endogenous RNAs network of peri-implantitis.

BACKGROUND: Peri-implantitis is an inflammation that occurs around the implant, resulting in varying degrees of inflammatory damage to the soft and hard tissues. The characteristic criterion is the loss of the supporting bone in an inflammatory environment. However, the specific mechanisms and biomarkers involved in peri-implantitis remain to be further studied. Recently, competing endogenous RNAs (ceRNA) and immune microenvironment have been found to play a more important role in the inflammatory process. In our study, we analyzed the expression of immune related microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and message RNAs (mRNAs) in peri-implantitis by analyzing GSE33774 and GSE57631. METHODS: In this study, we explored the expression profile data of immune-related lncRNAs, miRNAs and mRNAs, and constructed immune-related ceRNA network involved in the pathogenesis of peri-implantitis. In addition, the CIBERSORT was used to evaluate the content of immune cells in normal tissues and peri-implantitis to detect the immune microenvironment of peri-implantitis. RESULTS: In the analysis, 14 DElncRNAs, 16 DEmiRNAs, and 18 DEmRNAs were used to establish an immune related ceRNA network and the immune infiltration patterns associated with peri-implantitis was discovered. Through the mutual verification of the two datasets, we found that GSK3B and miR-1297 may have important significance in the immune microenvironment and pathogenesis of peri-implantitis and GSK3B was closely related to four types of immune cells, especially with the highest correlation with resting mast cells (P = 0.0003). CONCLUSIONS: Through immune-related ceRNA network, immune-related genes (IRGs) and immune cell infiltration can further comprehensively understand the pathogenesis of peri-implantitis, which built up an immunogenomic landscape with clinical significance for peri-implantitis.

CKLF1/CCR5 axis is involved in neutrophils migration of rats with transient cerebral ischemia.

BACKGROUND: Chemokine-like factor 1 (CKLF1) is a chemokine increased significantly in ischemic brain poststroke. It shows chemotaxis effects on various immune cells, but the mechanisms of CKLF1 migrating neutrophils are poorly understood. Recent studies have provided evidence that CC chemokine receptor 5 (CCR5), a receptor of CKLF1, is involved in ischemic stroke. PURPOSES: To investigate the effects of HIF-1α guided AAV in ischemic brain, investigating the outcome of stroke, and examining the involvement of CKLF1/CCR5 axis in recruitment of neutrophils. RESULTS: HIF-1α guided AAV knocked down CKLF1 in ischemic area and alleviated brain damage of rats. CKLF1 migrated neutrophils through CCR5, worsening inflammatory responses. Akt/GSK-3ß pathway may involve in CKLF1/CCR5 axis guided neutrophils chemotaxis. CONCLUSIONS: CKLF1/CCR5 axis is involved in neutrophils migration of rats with transient cerebral ischemia. CKLF1/CCR5 axis may be a useful target for stroke therapy.

Role of the PI3K/AKT (mTOR and GSK3ß) signalling pathway and photobiomodulation in diabetic wound healing.

Activated phosphatidylinositol 3 kinase/Protein kinase B (PI3K/AKT) signalling with increased or reduced mTOR and GSK3ß activity influences the wound repair process. Diabetic wounds, usually ulcerated, are characterised by reduced growth factors and cellular performance. The occurrence of diabetic ulcers is linked to peripheral arterial disease, neuropathy, and wound contamination. Lasers or light emitting diodes (LEDs) provide photon energy with therapeutic benefits (Photobiomodulation-PBM), and has been broadly commended to quicken diabetic wound healing. PBM is efficient in the visible red and near-infrared electromagnetic spectrum, and fluencies ranging from 2 to 6 J/cm2. However, cellular and molecular mechanisms induced by PBM are not fully understood. In this review we discuss PBM and the PI3K/AKT pathway with specific focus on the mTOR and GSK3ß downstream activity in diabetic wound healing.

GSK-3ß activation index is a potential indicator for recurrent inflammation of chronic rhinosinusitis without nasal polyps.

Chronic rhinosinusitis without nasal polyps (CRSsNP) is one of the most common otorhinolaryngologic diseases worldwide. However, the underlying mechanism remains unclear. In this study, the expression of glycogen synthase kinase 3 (GSK-3) was quantitatively evaluated in patients with CRSsNP (n = 20) and healthy controls (n = 20). The mRNA levels of GSK-3α and GSK-3ß were examined by qPCR, the immunoreactivities of GSK-3ß and nuclear factor-κB (NF-κB) were examined by immunohistochemistry (IHC) staining, and the protein levels of GSK-3ß, phospho-GSK-3ß (p-GSK-3ß, s9) and NF-κB were examined using Western blot analysis. We found that GSK-3 was highly expressed in both CRSsNP and control groups without significant difference in both GSK-3ß mRNA and protein levels. However, when compared with healthy control group, the GSK-3ß activation index, defined as the ratio of GSK-3ß over p-GSK-3ß, was significantly decreased, whereas the NF-κB protein abundance was significantly increased in CRSsNP group (P < 0.05). Strikingly, the GSK-3ß activation index, was highly correlated with NF-κB protein level, as well as CT scores in CRSsNP group (P < 0.05). It was also highly correlated with the mRNA expressions of inflammation-related genes, including T-bet, IFN-γ and IL-4 in CRSsNP group (P < 0.05). Our findings suggest that GSK-3ß activation index, reflecting the inhibitory levels of GSK-3ß through phosphorylation, may be a potential indicator for recurrent inflammation of CRSsNP, and that the insufficient inhibitory phosphorylation of GSK-3ß may play a pivotal role in the pathogenesis of CRSsNP.

Amphiregulin Confers Regulatory T Cell Suppressive Function and Tumor Invasion via the EGFR/GSK-3ß/Foxp3 Axis.

Previous studies mainly focused on the role of the epidermal growth factor receptor (EGFR) in tumor cells, whereas the effects of the EGFR on immune responses has not been determined. Our study shows that the EGFR signaling pathway play a role in the regulation of regulatory T cells (Treg cells) in cancer patients. The EGF-like growth factor Amphiregulin (AREG) protein was frequently up-regulated in a tissue microarray, which was associated with worse overall survival. Additionally, in sera, tissue specimens, and effusions of lung or gastric cancer patients, up-regulated AREG protein enhanced the suppressive function of Treg cells. AREG maintained the Treg cell suppressive function via the EGFR/GSK-3ß/Foxp3 axis in vitro and in vivo Furthermore, inhibition of EGFR by the tyrosine kinase inhibitor gefitinib restored the activity of GSK-3ß and attenuated Treg cell function. ß-TrCP was involved in GSK-3ß-mediated Foxp3 degradation, and mass spectrometry identified Lys356 as the ubiquitination site of Foxp3 by ß-TrCP. These findings demonstrate the posttranslational regulation of Foxp3 expression by AREG in cancer patients through AREG/EGFR/GSK-3ß signaling, which could lead to Foxp3 protein degradation in Treg cells and a potential therapeutic target for cancer treatment.

Non-tumor tissue derived interleukin-17B activates IL-17RB/AKT/ß-catenin pathway to enhance the stemness of gastric cancer.

Inflammation is a critical component involved in tumor progression. Interleukin-17 (IL-17) belongs to a relatively new family of cytokines that has been associated with the progression of cancers. However, the role of IL-17B/IL-17RB (IL-17 receptor B) signaling to stemness of gastric cancer remains unknown. Here, we confirmed that the expression of IL-17RB in gastric cancer tissues was significantly increased, that overexpression was associated with poor prognosis of gastric cancer patients, and that overexpression was positively correlated with some stemness markers. Interestingly, the expression of IL-17B was upregulated in patient serum rather than gastric tumor tissues. Furthermore, exogenous rIL-17B significantly promoted the stemness of gastric cancer cells depending on IL-17RB and induced the expression of IL-17RB. Simultaneously, the expression of phosphorylated AKT, GSK-3ß, and ß-catenin as well as the nuclear translocation of ß-catenin were significantly increased in the MGC-803 cell in a dose-dependent manner, when treated with rIL-17B. The AKT inhibitor, LY294002, and the knockdown of AKT expression reversed the rIL-17B-induced upregulation of ß-catenin and some stemness markers. Together, our results indicate that the IL-17B/IL-17RB signal can promote the growth and migration of tumor cells, and upregulate cell stemness through activating the AKT/ß-catenin pathway in gastric cancer, suggesting that IL-17RB may be a novel target in human gastric cancer therapy.