AIM:To investigate the effects of macrophage galactose-type lectin 1(Mgl1)gene deletion on he-matopoietic stem/progenitor cells(HSPCs)under steady-state conditions and inflammation.METHODS:Mice were di-vided into a control group(wild-type)and an experimental group(Mgl1 gene-deleted).Flow cytometry was used to ana-lyze the proportions of various hematopoietic cell lineages in the peripheral blood and bone marrow of both groups,assess-ing the impact of Mgl1 gene deletion on steady-state hematopoiesis(n=3～4).Transplantation and colony-forming assays were utilized to evaluate the effects of Mgl1 gene deletion onthe repopulation capacity and colony-forming ability of HSPCs(n=5).The LPS-induced inflammation model was employed to examine the effects of Mgl1 gene deletion on the inflamma-tory response of HSPCs both in vitro and in vivo(n=5～8).Western blot and RT-qPCR were conducted to analyze the alter-ations in signaling pathways regulated by Mgl1 in the inflammatory response of HSPCs(n=3).RESULTS:(1)Mgl1 gene deletion had no significant effecton steady-state hematopoiesis(P>0.05).(2)Mgl1 gene deletion promoted inflam-mation-induced cell differentiation of HSPCs(P<0.01).(3)Mgl1 gene deletion accelerated the exhaustion of HSPCs un-der prolonged inflammatory conditions(P<0.01).(4)Mgl1 was found to regulate the inflammatory response of HSPCs via the NF-κB signaling pathway.CONCLUSION:Mgl1 gene deletion enhances the inflammatory response of HSPCs via the NF-κB signaling pathway.

Loss of protein homeostasis is a hallmark of cellular senescence, and ribosome pausing plays a crucial role in the collapse of proteostasis. However, our understanding of ribosome pausing in senescent cells remains limited. In this study, we utilized ribosome profiling and G-quadruplex RNA immunoprecipitation sequencing techniques to explore the impact of RNA G-quadruplex (rG4) on the translation efficiency in senescent cells. Our results revealed a reduction in the translation efficiency of rG4-rich genes in senescent cells and demonstrated that rG4 structures within coding sequence can impede translation both in vivo and in vitro. Moreover, we observed a significant increase in the abundance of rG4 structures in senescent cells, and the stabilization of the rG4 structures further exacerbated cellular senescence. Mechanistically, the RNA helicase DHX9 functions as a key regulator of rG4 abundance, and its reduced expression in senescent cells contributing to increased ribosome pausing. Additionally, we also observed an increased abundance of rG4, an imbalance in protein homeostasis, and reduced DHX9 expression in aged mice. In summary, our findings reveal a novel biological role for rG4 and DHX9 in the regulation of translation and proteostasis, which may have implications for delaying cellular senescence and the aging process.
G-Quadruplexes ; Cellular Senescence ; Ribosomes/genetics* ; Humans ; Animals ; Mice ; DEAD-box RNA Helicases/genetics* ; Protein Biosynthesis ; RNA/chemistry* ; Neoplasm Proteins

Objective To investigate the effect of tissue-resident memory T cells(TRM)on imiquimod-induced psoriatic-like skin lesions in mice,and to elucidate the underlying mechanisms of TRM involvement in this process.Methods Forty female BALB/c mice were procured and randomly allocated into four groups:ten in the blank control group,and thirty for the establishment of a psoriasis mouse model.Following successful modeling,the thirty mice were further randomized into three groups:the model control group,the methotrexate-treated group,and the imiquimod-treated group,with ten mice in each group.Mice in the blank control group and model control group were uniformly treated with Vaseline for intervention.The methotrexate group and the imiquimod group were treated with 62.5mg of 5％imiquimod cream.The methotrexate group was administered by gavage at a dose of 1 mg/kg,and the gavage volume of each group was 10 mL/kg.The model control group,blank group and imiquimod group were gavaged with the same volume of normal saline.Treatment was conducted over six consecutive days.Subsequently,comparisons were made across groups regarding the psoriasis area and severity index(PASI),histopathological findings,inflammatory cytokine levels,and TRM cell levels.Results(1)The imiquimod group exhibited signifi-cantly lower scores for erythema(2.54±0.32),skin thickening(2.59±0.25),and scaling(2.52±0.29)compared to the methotrexate group,model control group,and blank control group(P<0.05).Additionally,the methotrexate group demonstrated reduced scores for erythema,skin thickening,and scaling compared to the model control group(P<0.05).(2)Hematoxylin-eosin(HE)staining revealed that the epidermis in the methotrexate group became thin-ner,with fewer parakeratotic cells and increased hair follicles.Conversely,the imiquimod group displayed abnor-mal cell morphology and relatively thicker white skin after modeling.(3)The imiquimod group showed significantly lower levels of TNF-α(51.63±4.39 pg/mL),IL-1β(35.53±4.15 pg/mL),IFN-γ(23.43±3.41 pg/mL),and IL-23(15.24±2.95 pg/mL)compared to the methotrexate and model control groups(P<0.05).Similarly,the methotrexate group exhibited reduced levels of TNF-α,IL-1β,IFN-γ,and IL-23 compared to the model control group(P<0.05).(4)The imiquimod group had significantly lower levels of CD8+CD103+cells(15.39±2.31)than the methotrexate and model control groups(P<0.05).Furthermore,the methotrexate group demonstrated lower levels of CD8+CD103+cells compared to the model control group(P<0.05).Conclusion Miquimod induces heavier skin lesions,faster response,and more epidermal thickening in psoriasis like mice.CD8+CD103+TRM cells and inflammatory factors may be involved in the recurrence of psoriasis.

Objective To investigate the effect of tissue-resident memory T cells(TRM)on imiquimod-induced psoriatic-like skin lesions in mice,and to elucidate the underlying mechanisms of TRM involvement in this process.Methods Forty female BALB/c mice were procured and randomly allocated into four groups:ten in the blank control group,and thirty for the establishment of a psoriasis mouse model.Following successful modeling,the thirty mice were further randomized into three groups:the model control group,the methotrexate-treated group,and the imiquimod-treated group,with ten mice in each group.Mice in the blank control group and model control group were uniformly treated with Vaseline for intervention.The methotrexate group and the imiquimod group were treated with 62.5mg of 5％imiquimod cream.The methotrexate group was administered by gavage at a dose of 1 mg/kg,and the gavage volume of each group was 10 mL/kg.The model control group,blank group and imiquimod group were gavaged with the same volume of normal saline.Treatment was conducted over six consecutive days.Subsequently,comparisons were made across groups regarding the psoriasis area and severity index(PASI),histopathological findings,inflammatory cytokine levels,and TRM cell levels.Results(1)The imiquimod group exhibited signifi-cantly lower scores for erythema(2.54±0.32),skin thickening(2.59±0.25),and scaling(2.52±0.29)compared to the methotrexate group,model control group,and blank control group(P<0.05).Additionally,the methotrexate group demonstrated reduced scores for erythema,skin thickening,and scaling compared to the model control group(P<0.05).(2)Hematoxylin-eosin(HE)staining revealed that the epidermis in the methotrexate group became thin-ner,with fewer parakeratotic cells and increased hair follicles.Conversely,the imiquimod group displayed abnor-mal cell morphology and relatively thicker white skin after modeling.(3)The imiquimod group showed significantly lower levels of TNF-α(51.63±4.39 pg/mL),IL-1β(35.53±4.15 pg/mL),IFN-γ(23.43±3.41 pg/mL),and IL-23(15.24±2.95 pg/mL)compared to the methotrexate and model control groups(P<0.05).Similarly,the methotrexate group exhibited reduced levels of TNF-α,IL-1β,IFN-γ,and IL-23 compared to the model control group(P<0.05).(4)The imiquimod group had significantly lower levels of CD8+CD103+cells(15.39±2.31)than the methotrexate and model control groups(P<0.05).Furthermore,the methotrexate group demonstrated lower levels of CD8+CD103+cells compared to the model control group(P<0.05).Conclusion Miquimod induces heavier skin lesions,faster response,and more epidermal thickening in psoriasis like mice.CD8+CD103+TRM cells and inflammatory factors may be involved in the recurrence of psoriasis.

AIM:To investigate the effects of macrophage galactose-type lectin 1(Mgl1)gene deletion on he-matopoietic stem/progenitor cells(HSPCs)under steady-state conditions and inflammation.METHODS:Mice were di-vided into a control group(wild-type)and an experimental group(Mgl1 gene-deleted).Flow cytometry was used to ana-lyze the proportions of various hematopoietic cell lineages in the peripheral blood and bone marrow of both groups,assess-ing the impact of Mgl1 gene deletion on steady-state hematopoiesis(n=3～4).Transplantation and colony-forming assays were utilized to evaluate the effects of Mgl1 gene deletion onthe repopulation capacity and colony-forming ability of HSPCs(n=5).The LPS-induced inflammation model was employed to examine the effects of Mgl1 gene deletion on the inflamma-tory response of HSPCs both in vitro and in vivo(n=5～8).Western blot and RT-qPCR were conducted to analyze the alter-ations in signaling pathways regulated by Mgl1 in the inflammatory response of HSPCs(n=3).RESULTS:(1)Mgl1 gene deletion had no significant effecton steady-state hematopoiesis(P>0.05).(2)Mgl1 gene deletion promoted inflam-mation-induced cell differentiation of HSPCs(P<0.01).(3)Mgl1 gene deletion accelerated the exhaustion of HSPCs un-der prolonged inflammatory conditions(P<0.01).(4)Mgl1 was found to regulate the inflammatory response of HSPCs via the NF-κB signaling pathway.CONCLUSION:Mgl1 gene deletion enhances the inflammatory response of HSPCs via the NF-κB signaling pathway.

AIM:This study aim to investigate the effects of lipopolysaccharide(LPS)-induced inflammation on the aging phenotype of hematopoietic stem/progenitor cells(HSPCs)in the bone marrow(BM)and spleen of mice.METHODS:(1)Young(2-month old)wild-type(WT)mice were treated with LPS to establish an actue inflammation model.The percentage of HSPCs in the BM and spleen of mice after LPS stimulation,as well as the ratio of mature cells in peripheral blood(PB)and spleen,were analyzed using flow cytometry.The proliferation of HSPCs in the BM and spleen was evaluated by examining the expression of the proliferation marker Ki67.In addition,changes in CD45 expression on HSPCs in the spleen of mice following LPS exposure were investigated by flow cytometry.(2)The percentage of HSPCs in BM and mature cells in PB and spleen of both young(2-month old)and old(24-month old)WT mice were analyzed by flow cytometry.(3)The transcriptome changes of hematopoietic stem cells(HSCs)after LPS stimulation was performed by an in silico analysis.RESULTS:(1)Mice exposed to LPS exhibited a significant increase in the percentage of HSPCs in BM and a marked elevation in the percentages of myeloid cells in PB and spleen compared to the mice in control group(P<0.05).(2)LPS exposure resulted in increased spleen weight and cell counts(P<0.05),along with a higher per-centage of HSPCs in the spleen compared to controls(P<0.05).(3)LPS stimulation promoted the proliferation of HSPCs in the BM and spleen(P<0.05).(4)The expression of CD45 was reduced on HSPCs from spleen of mice after LPS stimu-lation(P<0.01).(5)In comparison to young mice,aged mice showed an increase in spleen weight and a higher percent-age of HSPCs in the spleen(P<0.05).(6)Aged mice,in comparison to young mice,demonstrated a significantly higher percentage of HSPCs in the BM and myeloid skewing in the PB and spleen(P<0.01).(7)The silico analysis revealed up-regualtion of reactive oxygen species(ROS)and apoptosis signaling in HSPCs following LPS stimulation.CONCLU-SION:Young HSPCs stimulated by LPS exhibited an increase in cell number,a bias towards myeloid differentiation,en-hanced extramedullary hematopoiesis,and elevated levels of ROS and apoptosis,all of which collectively manifested the aging phenotype of HSPCs.

AIM:To investigate the role and molecular mechanisms of SMARCA4(SWI/SNF-related,matrix-associated,actin-dependent regulator of chromatin,subfamily A,member 4)in ferroptosis.METHODS:(1)Human fi-brosarcoma HT1080 cells were treated with dimethyl sulfoxide(DMSO)and different concentrations(31.25,62.5 and 125 nmol/L)of Ras-selective lethal small molecule 3(RSL3;ferroptosis inducer).Each treatment had 3 replicate wells of cells.The protein levels of SMARCA4 were detected by Western blot.(2)Two small interfering RNAs(siSMARCA4-1 and siSMARCA4-2)were constructed according to the SMARCA4 gene sequence.After SMARCA4 knockdown,each treat-ment had 3 replicate wells of cells,and the protein levels of SMARCA4 were determined by Western blot.Effects of DMSO,necrostatin 2 racemate(Nec-1s;necroptosis inhibitor),Z-VAD(OMe)-FMK(Z-VAD,pan-caspase inhibitor/apoptosis inhibitor)and ferrostatin-1(Fer-1,ferroptosis inhibitor)on cell viability were assessed using high-content analy-sis.The levels of ferroptosis indicators,including prostaglandin-endoperoxide synthase 2(PTGS2)transcription,lipid peroxidation,reactive oxygen species(ROS),labile iron pool(LIP)and glutathione,were determined by RT-qPCR and flow cytometry.The mRNA expression levels of pivotal iron metabolism genes,ferroptosis-related ROS regulatory genes,and cholesterol synthesis-related genes were measured using RT-qPCR.Impact of cholesterol on the cell viability were as-sessed using high-content analysis.(3)Common differential gene analysis and gene ontology(GO)enrichment analysis were performed on published online data.RESULTS:(1)Treatment with RSL3 significantly reduced the protein level of SMARCA4(P＜0.05).(2)Knockdown of SMARCA4 resulted in ferroptosis.(3)Knockdown of SMARCA4 did not induce ferroptosis by modulating the LIP and the transcription levels of ROS-related genes.(4)Knockdown of SMARCA4 affected the pathways associated with the cell membrane,lipid raft,and cholesterol synthesis.(5)Addition of cholesterol to cell culture medium rescued the ferroptosis induced by SMARCA4 knockdown(P＜0.01).CONCLUSION:Treatment with RSL3 reduces the protein level of SMARCA4 in human fibrosarcoma HT1080 cells,and inhibition of cholesterol synthesis by SMARCA4 knockdown leads to the ferroptosis of HT1080 cells.

The maintenance of hematopoietic stem cells (HSCs) is a complex process involving numerous cell-extrinsic and -intrinsic regulators. The first member of the cyclin-dependent kinase family of inhibitors to be identified, p21, has been reported to perform a wide range of critical biological functions, including cell cycle regulation, transcription, differentiation, and so on. Given the previous inconsistent results regarding the functions of p21 in HSCs in a p21-knockout mouse model, we employed p21-tdTomato (tdT) mice to further elucidate its role in HSCs during homeostasis. The results showed that p21-tdT+ HSCs exhibited increased self-renewal capacity compared to p21-tdT- HSCs. Zbtb18, a transcriptional repressor, was upregulated in p21-tdT+ HSCs, and its knockdown significantly impaired the reconstitution capability of HSCs. Furthermore, p21 interacted with ZBTB18 to co-repress the expression of cKit in HSCs and thus regulated the self-renewal of HSCs. Our data provide novel insights into the physiological role and mechanisms of p21 in HSCs during homeostasis independent of its conventional role as a cell cycle inhibitor.
Animals ; Hematopoietic Stem Cells/cytology* ; Cyclin-Dependent Kinase Inhibitor p21/genetics* ; Mice ; Cell Self Renewal ; Repressor Proteins/genetics* ; Mice, Inbred C57BL ; Mice, Knockout ; Humans ; Gene Expression Regulation

Objective:To investigate the inhibitory effect and molecular mechanism of microRNA-30d (miR-30d) in the process of proliferation, migration and invasion of malignant mesothelioma cell line MSTO-211H.Methods:In April 2017, the human MSTO-211H cells was used to establish miR-30d overexpressed MSTO-211H cell model by transfection of miR-30d mimics. The qRT-PCR was performed to detect the expression level of miR-30d in the cells transfected miR-30d mimics. The effects of miR-30d on the proliferation, apoptosis, migration and invasion of MSTO-211H cells were analyzed by CCK-8 experiment, flow cytometry, cell scratch experiment and Transwell method.Results:After transfection of miR-30d, the expression level of miR-30d in the MSTO-211H+miR-30d cells group was significantly higher than MSTO-211H+miR NC cells group ( P<0.01) . The cell activity of MSTO-211H+miR-30d group (105.13%±2.35%) was significantly lower than MSTO-211H+miR NC cells group (115.40%±1.35%) , and the level of apoptosis (3.97%±0.36%) was significantly higher than MSTO-211H+miR NC cells group (1.47%±0.10%) ( P<0.01) . The relative migration areas at 12 and 24 h of MSTO-211H+miR-30d cells group (9.35±3.16 μm 2 and 58.19±1.82 μm 2) were significantly lower than MSTO-211H+miR NC cells group (54.42 ±5.26 μm 2 and 88.32 ±1.96 μm 2) ( P<0.01) . Compared with the MSTO-211H+miR NC cells group, the numbers of cell migration and cell invasion were reduced in the MSTO-211H+miR-30d cells group ( P<0.01) . Conclusion:miR-30d can regulate the progression of malignant pleural mesothelioma by inhibiting the proliferation, apoptosis, migration and invasion of MSTO-211H cells.

Objective:To explore the chronic toxicity and its potential mechanism of multi-walled carbon nanotube (MWCNT) in human pleural mesothelial cells.Methods:A sustainable exposure of MeT-5A cells to MWCNT at 10 μg/cm 2 for one year was conducted in 2016. During the exposure, the cell images and cell proliferation was recorded every 4 weeks. The cell apoptosis, cell cycle, cell migration and cell invasion were compared between the control cells and the cells after MWCNT exposure. Finally, the gene expression was screened with Affymetrix clariom D assay, and some of the significantly differential expressed genes was verified by RT-PCR. Results:Compared with the control group, the proliferation ability of the cells in the 1-year exposed group was significantly increased, and the rate of proliferation was about 2-3 times as that in the Control Group ( F=481.32, P<0.05) . MeT-5A cells all showed cell cycle arrest effect, which showed the increase of G1 phase and the decrease of s phase and G2 phase ( F=14.94, P<0.05) . The apoptosis rate of cells in the treated group was significantly higher than that in the control group after 6 months ( F=15.12, P<0.05) , but the early apoptosis rate and the total apoptosis rate of cells in the treated group were not significantly different from those in the control group after 1 year ( F=3.97, P<0.05) . The cell migration and invasion were both promoted by MWCNT. Furthermore, the differentially expressed genes was screened, to find 2, 878 genes with more than 2 folds changes. To further verified, RT-PCR was conducted with PIK3R3、WNT2B、VANGL2、ANXA1, and their expression changes were consistent with above. Conclusion:MWCNT might have a carcinogenic potential to MeT-5A cells after the long term exposure.