BACKGROUND: T cell dysfunction, which includes exhaustion, anergy, and senescence, is a distinct T cell differentiation state that occurs after antigen exposure. Although T cell dysfunction has been a cornerstone of cancer immunotherapy, its potential in transplant research, while not yet as extensively explored, is attracting growing interest. Interferon regulatory factor 4 (IRF4) has been shown to play a pivotal role in inducing T cell dysfunction. METHODS: A novel ultra-low-dose combination of Trametinib and Rapamycin, targeting IRF4 inhibition, was employed to investigate T cell proliferation, apoptosis, cytokine secretion, expression of T-cell dysfunction-associated molecules, effects of mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) signaling pathways, and allograft survival in both in vitro and BALB/c to C57BL/6 mouse cardiac transplantation models. RESULTS: In vitro , blockade of IRF4 in T cells effectively inhibited T cell proliferation, increased apoptosis, and significantly upregulated the expression of programmed cell death protein 1 (PD-1), Helios, CD160, and cytotoxic T lymphocyte-associated antigen (CTLA-4), markers of T cell dysfunction. Furthermore, it suppressed the secretion of pro-inflammatory cytokines interferon (IFN)-γ and interleukin (IL)-17. Combining ultra-low-dose Trametinib (0.1 mg·kg -1 ·day -1 ) and Rapamycin (0.1 mg·kg -1 ·day -1 ) demonstrably extended graft survival, with 4 out of 5 mice exceeding 100 days post-transplantation. Moreover, analysis of grafts at day 7 confirmed sustained IFN regulatory factor 4 (IRF4) inhibition, enhanced PD-1 expression, and suppressed IFN-γ secretion, reinforcing the in vivo efficacy of this IRF4-targeting approach. The combination of Trametinib and Rapamycin synergistically inhibited the MAPK and mTOR signaling network, leading to a more pronounced suppression of IRF4 expression. CONCLUSIONS Targeting IRF4, a key regulator of T cell dysfunction, presents a promising avenue for inducing transplant immune tolerance. In this study, we demonstrate that a novel ultra-low-dose combination of Trametinib and Rapamycin synergistically suppresses the MAPK and mTOR signaling network, leading to profound IRF4 inhibition, promoting allograft acceptance, and offering a potential new therapeutic strategy for improved transplant outcomes. However, further research is necessary to elucidate the underlying pharmacological mechanisms and facilitate translation to clinical practice.
Animals ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Interferon Regulatory Factors/metabolism* ; Heart Transplantation/methods* ; T-Lymphocytes/immunology* ; Sirolimus/therapeutic use* ; Pyridones/therapeutic use* ; Graft Survival/drug effects* ; Pyrimidinones/therapeutic use* ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Male ; Signal Transduction/drug effects*

One of the basic questions in the aging field is whether there is a fundamental difference between the aging of lower invertebrates and mammals. A major difference between the lower invertebrates and mammals is the abundancy of noncoding RNAs, most of which are not conserved. We have previously identified a noncoding RNA Terc-53 that is derived from the RNA component of telomerase Terc. To study its physiological functions, we generated two transgenic mouse models overexpressing the RNA in wild-type and early-aging Terc-/- backgrounds. Terc-53 mice showed age-related cognition decline and shortened life span, even though no developmental defects or physiological abnormality at an early age was observed, indicating its involvement in normal aging of mammals. Subsequent mechanistic study identified hyaluronan-mediated motility receptor (Hmmr) as the main effector of Terc-53. Terc-53 mediates the degradation of Hmmr, leading to an increase of inflammation in the affected tissues, accelerating organismal aging. adeno-associated virus delivered supplementation of Hmmr in the hippocampus reversed the cognition decline in Terc-53 transgenic mice. Neither Terc-53 nor Hmmr has homologs in C. elegans. Neither do arthropods express hyaluronan. These findings demonstrate the complexity of aging in mammals and open new paths for exploring noncoding RNA and Hmmr as means of treating age-related physical debilities and improving healthspan.
Animals ; Mice ; RNA, Untranslated/metabolism* ; Aging/genetics* ; Mice, Transgenic ; Telomerase/metabolism* ; RNA/genetics* ; Hippocampus/metabolism* ; Humans ; Mice, Inbred C57BL

The incomplete degradation of tumour cells by macrophages (Mϕ) is a contributing factor to tumour progression and metastasis, and the degradation function of Mϕ is mediated through phagosomes and lysosomes. In our preliminary experiments, we found that overactivation of NADPH oxidase 2 (NOX2) reduced the ability of Mϕ to degrade engulfed tumour cells. Above this, we screened out liquiritin from Glycyrrhiza uralensis Fisch, which can significantly inhibit NOX2 activity and inhibit tumours, to elucidate that suppressing NOX2 can enhance the ability of Mϕ to degrade tumour cells. We found that the tumour environment could activate the NOX2 activity in Mϕ phagosomes, causing Mϕ to produce excessive reactive oxygen species (ROS), thus prohibiting the formation of phagolysosomes before degradation. Conversely, inhibiting NOX2 in Mϕ by liquiritin can reduce ROS and promote phagosome-lysosome fusion, therefore improving the enzymatic degradation of tumour cells after phagocytosis, and subsequently promote T cell activity by presenting antigens. We further confirmed that liquiritin down-regulated the expression of the NOX2 specific membrane component protein gp91 phox, blocking its binding to the NOX2 cytoplasmic component proteins p67 phox and p47 phox, thereby inhibiting the activity of NOX2. This study elucidates the specific mechanism by which Mϕ cannot degrade tumour cells after phagocytosis, and indicates that liquiritin can promote the ability of Mϕ to degrade tumour cells by suppressing NOX2.

The incomplete degradation of tumour cells by macrophages(Mφ)is a contributing factor to tumour progression and metastasis,and the degradation function of Mφ is mediated through phagosomes and lysosomes.In our preliminary experiments,we found that overactivation of NADPH oxidase 2(NOX2)reduced the ability of Mφ to degrade engulfed tumour cells.Above this,we screened out liquiritin from Glycyrrhiza uralensis Fisch,which can significantly inhibit NOX2 activity and inhibit tumours,to elucidate that suppressing NOX2 can enhance the ability of Mφ to degrade tumour cells.We found that the tumour environment could activate the NOX2 activity in Mφ phagosomes,causing Mφ to produce excessive reactive oxygen species(ROS),thus prohibiting the formation of phagolysosomes before degradation.Conversely,inhibiting NOX2 in Mφ by liquiritin can reduce ROS and promote phagosome-lysosome fusion,therefore improving the enzymatic degradation of tumour cells after phagocytosis,and subse-quently promote T cell activity by presenting antigens.We further confirmed that liquiritin down-regulated the expression of the NOX2 specific membrane component protein gp91 phox,blocking its binding to the NOX2 cytoplasmic component proteins p67 phox and p47 phox,thereby inhibiting the activity of NOX2.This study elucidates the specific mechanism by which Mφ cannot degrade tumour cells after phagocytosis,and indicates that liquiritin can promote the ability of Mφ to degrade tumour cells by suppressing NOX2.

Long non-coding RNAs(lncRNAs),a group of non-coding RNAs with lengths exceeding 200 nucleotides,play a crucial role in the human transcriptome,particularly in various types of cancers,where they are pivotal in regulating the tumor immune microenvironment and tumor cell immune evasion.However,there is currently a lack of systematic literature review.Myeloid-derived suppressor cells(MDSCs),a subset of myeloid cells with immunosuppressive functions,play a significant role in cancer by directly and indirectly suppressing T cell activity,promoting the expansion of regulatory T cells,modulating the tumor microenvironment,and facilitating tumor metastasis.This review emphasizes the importance of in-depth investigation into the regulatory mechanisms of MDSCs for the discovery of effective tumor therapeutic targets and the development of novel treatment strategies.With further understanding and research into the relationship between lncRNAs and MDSCs,it is anticipated that more targets and new therapeutic approaches will be identified for cancer treatment,thereby improving clinical outcomes for patients.

Objective To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer.Methods Tumor associated fibroblasts(CAFs)co-cultured with breast cancer cells were treated with metformin,and the changes in expressions of hypoxia-inducible factor-1α(HIF-1α),p-AMPK,stroma-derived factor-1(SDF-1)and interleukin-8(IL-8)in the CAFs were detected using ELISA,RT-qPCR or Western blotting;Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1,IL-8 and TGF-β1.The effects of HIF-1α shRNA or overexpression plasmid,AMPK shRNA,and treatment with OG(a proline hydroxylase inhibitor)or 2-OXO(a proline hydroxylase activator)were examined on p-AMPK,HIF-1α,SDF-1 and IL-8 expressions and invasiveness of the CAFs.Results Metformin treatment significantly increased the expression levels of p-AMPK,SDF-1 and IL-8(P<0.05)and decreased HIF-1α expression(P<0.05)without affecting AMPK expression level(P>0.05)in the CAFs.The invasion ability of metformin-treated breast cancer cells was significantly decreased(P<0.05).Exogenous SDF-1 and IL-8,HIF-1α overexpression,and OG-induced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion(P<0.05)and HIF-1α,SDF-1 and IL-8 expressions in CAFs(P<0.05).Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells(P<0.05).P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells(P<0.05).Treatment with TGF-β1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells(P<0.05).Conclusion Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.

Objective To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer.Methods Tumor associated fibroblasts(CAFs)co-cultured with breast cancer cells were treated with metformin,and the changes in expressions of hypoxia-inducible factor-1α(HIF-1α),p-AMPK,stroma-derived factor-1(SDF-1)and interleukin-8(IL-8)in the CAFs were detected using ELISA,RT-qPCR or Western blotting;Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1,IL-8 and TGF-β1.The effects of HIF-1α shRNA or overexpression plasmid,AMPK shRNA,and treatment with OG(a proline hydroxylase inhibitor)or 2-OXO(a proline hydroxylase activator)were examined on p-AMPK,HIF-1α,SDF-1 and IL-8 expressions and invasiveness of the CAFs.Results Metformin treatment significantly increased the expression levels of p-AMPK,SDF-1 and IL-8(P<0.05)and decreased HIF-1α expression(P<0.05)without affecting AMPK expression level(P>0.05)in the CAFs.The invasion ability of metformin-treated breast cancer cells was significantly decreased(P<0.05).Exogenous SDF-1 and IL-8,HIF-1α overexpression,and OG-induced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion(P<0.05)and HIF-1α,SDF-1 and IL-8 expressions in CAFs(P<0.05).Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells(P<0.05).P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells(P<0.05).Treatment with TGF-β1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells(P<0.05).Conclusion Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.

The disorder of group 3 innate lymphoid cells(ILC3)subgroup,such as the predominance of NCR-ILC3 but the deple-tion of NCR+ILC3,is unfavorable to damaged intestinal barrier repair,which leads to the prolongations and obstinacy of ulcerative colitis(UC).Our previous studies had shown that luteolin promoted NCRILC3 differentitating into NCR+ILC3 to improving the de-pletion of NCR+ILC3 in UC mice,while the mechanism is unclear.This article aimed to explore the underlying mechanism of luteolin enhancing the proportion NCR+ILC3.UC mice model was established with 2％DSS and Notch signaling was blocked,then luteolin was used to intervene.The results showed that the effect of luteolin on ameliorating disease symptoms in UC mice,including inhibit-ing the weight loss,reducing the pathological damage of colon mucosa,etc.,was diminished with blocking Notch signaling pathway.In addition,luteolin increased the proportion of NCR+ILC3,NCR+MNK3 and IL-22+ILC3,decreased intestinal permeability,pro-moted mucin secretion,and promoted ZO-1 and Occludin expression,the above effect of luteolin was neutralized by Notch inhibitor LY-411575.Luteolin activated the abnormally blocked Notch signaling pathway in UC mice.And molecular docking predicted the af-finity of luteolin for RBPJ to be-7.5 kcal·mol-1 in mouse,respectively;the affinity of luteolin for Notchl and RBPJ was respectively scored to be-6.4 kcal·mol-1 and-7.7 kcal·mol-1 homo sapiens.These results proved that luteolin is positive for enhancing the propor-tion of NCR+ILC3 via Notch signaling,and it provides a basis for targeting NCR+ILC3 for restoring intestinal barrier function to alle-viating ulcerative colitis.

OBJECTIVE: Our study aimed to conduct genomic characterization of Salmonella strains carrying the bla _NDM-1 gene in the intestinal tract of healthy individuals. The objectives were to underscore the importance of genomic surveillance for drug resistance in both commensal and pathogenic bacteria among healthy populations, and to establish protocols for regulating drug resistance plasmids based on the completion of a comprehensive map of drug resistance plasmid genomes. METHODS: We performed antimicrobial susceptibility testing and employed second- and third-generation sequencing techniques to analyze Salmonella strains harboring the bla _NDM-1 gene, to surveil drug-resistant bacteria in the intestines of healthy subjects. Sequence comparison was conducted using both core- and pan-genome approaches. Concurrently, conjugation experiments were carried out to assess the efficiency of plasmid transfer. RESULTS: We isolated a carbapenem-resistant Salmonella enterica serovar Typhimurium strain from a healthy food worker in China. This strain harbored an IncHI2/IncHI2A plasmid carrying bla _NDM-1 along with multiple antibiotic resistance genes (ARGs). Our findings highlight the potential for asymptomatic carriers to facilitate the transmission of ARGs. Pan-genomic analysis revealed that bla _NDM-1-positive plasmids could traverse bacterial species barriers, facilitating cross-host transmission. CONCLUSION This study marks the first detection of bla _NDM-1 in Salmonella strains isolated from healthy individuals. We underscore the risk associated with the transmission of conjugative hybrid plasmids carrying bla _NDM-1, which have the potential to be harbored and transmitted among healthy individuals. Enhanced surveillance of drug-resistant pathogens and plasmids in the intestinal microbiota of healthy individuals could provide insights into the risk of ARG transmission and pathways for population-wide dissemination via ARG transfer factors.
beta-Lactamases/genetics* ; Plasmids/genetics* ; Humans ; Anti-Bacterial Agents/pharmacology* ; China ; Microbial Sensitivity Tests ; Salmonella typhimurium/isolation & purification* ; Salmonella/isolation & purification* ; Salmonella Infections/microbiology*

Objective Our study aimed to conduct genomic characterization of Salmonella strains carrying the b/aNDM-1 gene in the intestinal tract of healthy individuals.The objectives were to underscore the importance of genomic surveillance for drug resistance in both commensal and pathogenic bacteria among healthy populations,and to establish protocols for regulating drug resistance plasmids based on the completion of a comprehensive map of drug resistance plasmid genomes.Methods We performed antimicrobial susceptibility testing and employed second-and third-generation sequencing techniques to analyze Salmonella strains harboring the b/aNDM-1 gene,to surveil drug-resistant bacteria in the intestines of healthy subjects.Sequence comparison was conducted using both core-and pan-genome approaches.Concurrently,conjugation experiments were carried out to assess the efficiency of plasmid transfer.Results We isolated a carbapenem-resistant Salmonella enterica serovar Typhimurium strain from a healthy food worker in China.This strain harbored an lncHI2/lncHI2A plasmid carrying blaNDM-1 along with multiple antibiotic resistance genes(ARGs).Our findings highlight the potential for asymptomatic carriers to facilitate the transmission of ARGs.Pan-genomic analysis revealed that b/aNDM-1-positive plasmids could traverse bacterial species barriers,facilitating cross-host transmission.Conclusion This study marks the first detection of b/aNDM-1 in Salmonella strains isolated from healthy individuals.We underscore the risk associated with the transmission of conjugative hybrid plasmids carrying blaNDM-1,which have the potential to be harbored and transmitted among healthy individuals.Enhanced surveillance of drug-resistant pathogens and plasmids in the intestinal microbiota of healthy individuals could provide insights into the risk of ARG transmission and pathways for population-wide dissemination via ARG transfer factors.