Objective To elucidate the molecular mechanism of sirtuin-3 (SIRT3) in regulating mitochondrial biogenesis in human renal tubular epithelial cells. Methods Cells were stimulated with different concentrations of H₂O₂ and divided into four groups: control (NC), 50 μmol/L H₂O₂, 110 μmol/L H₂O₂ and 150 μmol/L H₂O₂. SIRT3 protein expression was then measured. SIRT3 was knocked down with siRNA, and cells were further assigned to five groups: control (NC), negative-control siRNA (NCsi), SIRT3-siRNA (siSIRT3), NCsi+H₂O₂, and siSIRT3+H₂O₂. After 24 h, cellular adenosine triphosphate (ATP) and mitochondrial superoxide anion (O₂•⁻) levels were determined, together with mitochondrial expression of SIRT3, peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), mitochondrial transcription factor A (TFAM), superoxide dismutase 2 (SOD2), acetylated-SOD2 and adenosine monophosphate activated protein kinase α1 (AMPKα1). Results The 110 and 150 μmol/L H₂O₂ decreased SIRT3 protein (both P<0.05). ATP and mitochondrial O₂•⁻ did not differ between NC and NCsi groups (both P>0.05). Compared to the NCsi group, the siSIRT3 group exhibited elevated O₂•⁻ level, decreased SIRT3 protein and increased expression levels of SOD2 and acetylated SOD2 protein (all P<0.05). Compared to the NCsi group, the NCsi+H₂O₂ group exhibited decreased cellular ATP levels, elevated mitochondrial O₂•⁻ levels, and reduced protein expression levels of SIRT3, SOD2, TFAM, AMPKα1, PGC-1α and NRF1 (all P<0.05). Compared with the siSIRT3 group, the siSIRT3+H₂O₂ group showed a decrease in cellular ATP levels, an increase in mitochondrial O₂•⁻ levels, a decrease in SIRT3, SOD2, TFAM, AMPKα1, PGC-1α and NRF1 protein expression levels and a decrease in acetylated SOD2 protein expression levels (all P<0.05). Compared with the NCsi+H₂O₂ group, the siSIRT3+H₂O₂ group showed a decrease in cellular ATP levels, an increase in mitochondrial O₂•⁻ levels, a decrease in SIRT3, AMPKα1, PGC-1α and NRF1, TFAM protein expression levels, and an increase in SOD2 and acetylated SOD2 protein expression levels (all P<0.05). Conclusions SIRT3 promotes mitochondrial biogenesis in tubular epithelial cells via the AMPK/PGC-1α/NRF1/TFAM axis, representing a key mechanism through which SIRT3 ameliorates oxidative stress-induced mitochondrial dysfunction.

Objective To investigate the effects of fractionated low-dose ionizing radiation (LDIR) on the ferroptosis in human bronchial epithelial (HBE) cells as well as the associated differentially expressed genes (DEGs), biological processes, and signaling pathways. Methods HBE cells were exposed to different single doses of X-ray irradiation (0, 25, 50, 75, and 100 mGy) for 24, 48, and 72 h, respectively. The change in cell viability was detected by MTT assay. Cells were irradiated with 0, 25, 50, and 100 mGy X-rays 5 times, with 48 h between each irradiation and a dose rate of 50 mGy/min. Cells were harvested 24 h after irradiation for the measurement of the expression of ferroptosis-related genes SLC7A11 and GPX4 at the mRNA and protein levels, cellular iron content, and the expression of FTH1 and FTL mRNAs. High-throughput sequencing was used to screen for the DEGs in each dose group, followed by Gene Ontology-Biological Process (GO-BP) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and Gene Set Enrichment Analysis (GSEA). Results Compared with the control group, single-dose LDIR significantly increased cell proliferation at 75 mGy after 24 h (P < 0.05), at 50, 75, and 100 mGy after 48 h (P < 0.05), and at 75 and 100 mGy after 72 h (P < 0.05). Compared with the control group, at the end of the fifth fractionated LDIR, SLC7A11 and GPX4 mRNAs decreased at all doses (P < 0.05), SLC7A11 protein decreased at all doses, GPX4 protein decreased at 25 and 100 mGy, iron content increased at all doses, and FTH1 and FTL mRNAs decreased at all doses (P< 0.05). Sequencing analysis identified 248, 30, and 291 DEGs and 10, 2, and 9 ferroptosis-associated genes at the three doses compared to the control. Gene Ontology-Biological Process analysis showed that DEGs were mainly enriched in biological processes such as response to lipids, cell death, and response to unfolded proteins. Kyoto Encyclopedia of Genes and Genomes analysis showed that DEGs were mainly enriched in the JAK-STAT signaling pathway, lipids and atherosclerosis, ferroptosis, protein processing in the endoplasmic reticulum, and FoxO signaling pathway. Gene set enrichment analysis showed that DEGs were mainly enriched in ferroptosis, fatty acid degradation, and glutathione metabolism. Conclusion Fractionated low-dose radiation induced ferroptosis in HBE cells, and DEGs were predominantly enriched in biological processes and signaling pathways related to inflammation, ferroptosis, and endoplasmic reticulum stress.

Objective To investigate the role of the O-6-methylguanine-DNA methyltransferase (MGMT) gene-3′ untranslated region (UTR) microRNA-associated single nucleotide polymorphism (miRSNP) (rs7896488 G>A) in affecting miR-4297-targeted modulation of MGMT in senescence of lung cells with polymorphic genotypes induced by fractionated low dose ionizing radiation (LDIR). Methods i) MiRSNPs were predicted and screened using bioinformatics, and DNA from two types of lung cells, A549 cells and human bronchial epithelioid cells (HBE cells), was extracted for target gene sequencing. After co-transfection of pGL3c-MGMT-3′UTR-rs7896488 G>A reporter gene recombinant plasmid, pRL-TK Vector with micrON mimic NC #22 or micrON hsa-miR-4297 mimic (set up as the mimic NC group and the miR-4297 mimic group) in these two types of lung cells, dual luciferase reporter gene assay was performed. The relative expression of MGMT mRNA was detected by real-time fluorescence quantitative polymerase chain reaction, and the relative expression of MGMT protein was detected by Western blotting. ii) These two types of lung cells were randomly divided into the control group and irradiation group, which received either 0 or 100 mGy X-rays irradiation seven times. After irradiation, the cells were transfected with either micrON mimic NC #22 or micrON hsa-miR-4297 mimic, resulting in mimic NC + control group, miR-4297 mimic + control group, mimic NC + irradiation group, and miR-4297 mimic + irradiation group. Cells were collected for senescence-associated-β-galactosidase (SA-β-Gal) staining, and the relative expression of matrix metalloproteinase-9 (MMP-9) and chemokine (C-X-C motif) ligand-1 (CXCL-1) proteins was detected via Western blotting. Results i) The rs7896488 G>A was the miRSNP located in the conserved binding region targeted by miR-4297 in the MGMT gene 3′UTR. A549 cells were the rs7896488 GG wild-type homozygous genotype, while HBE cells were the rs7896488 GA heterozygous mutant genotype. In the miR-4297 mimic group, A549 and HBE cells carrying the rs7896488 G allele showed significantly lower dual-luciferase activity compared with that in the mimic NC group (both P<0.01). However, there was no significant difference in dual-luciferase activity between the two groups in both A549 and HBE cells carrying the rs7896488 A allele (both P>0.05). The relative expression levels of MGMT mRNA and MGMT protein of A549 cells in the miR-4297 mimic group were lower than those in the mimic NC group (both P<0.05). However, there was no significant difference in MGMT mRNA and MGMT protein of HBE cells between these two groups (both P>0.05). ii) The relative activity of SA-β-Gal and the relative expression of MMP-9 and CXCL-1 proteins of A549 cells in the miR-4297 mimic+irradiation group were higher than those in the mimic NC + control group, the miR-4297 mimic + control group, and the mimic NC + irradiation group (all P<0.05). The relative activity of SA-β-Gal and the relative expression of MMP-9 and CXCL-1 proteins of HBE cells in the miR-4297 mimic + irradiation group were higher than those in the mimic NC + control group and the miR-4297 mimic + control group (all P<0.05), while there was no significant difference compared with those in the mimic NC + irradiation group (all P>0.05). Conclusion MGMT-3′UTR-miRSNP rs7896488 G>A plays a role in LDIR-induced senescence of lung cells with different polymorphic genotypes by affecting miR-4297-targeted regulation of MGMT.

Objective To investigate the induction of senescence in L02 hepatocytes by low-dose fractionated X-ray radiation and its effects on oxidative stress, oxidative damage, and nuclear factor-κB (NF-κB) pathway protein levels. Methods L02 cells were subjected to fractionated X-ray irradiation at doses of 0.1, 0.2, and 0.5 Gy per fraction for a total of six fractions. Assays were performed 24 hours after the final irradiation. Measurements included SA-β-gal staining, the mRNAs of senescence-related genes p53 and p21 and their encoded proteins, mRNAs of genes encoding senescence-associated secretory phenotype factors (IL-6, IL-8, GM-CSF, MMP-15), reactive oxygen species, oxidative and anti-oxidative markers (malondialdehyde, glutathione, superoxide dismutase), DNA oxidative damage markers (8-OHdG and γ-H2AX), and NF-κB pathway protein levels. Results Compared with the control group, at 24 hours after the end of six irradiations, the number of cells positive in SA-β-gal staining was significantly increased in all dose groups. The mRNA and protein levels of p21 and p53 were significantly elevated in the 0.2 Gy × 6 and 0.5 Gy × 6 groups (P < 0.05). The mRNA levels of genes encoding IL-6, GM-CSF, and MMP-15 were significantly increased in all dose groups (P < 0.05). The mRNA levels of the gene encoding IL-8 were significantly increased in the 0.2 Gy × 6 and 0.5 Gy × 6 groups (P < 0.05). The levels of reactive oxygen species, malondialdehyde, and glutathione were significantly increased in all dose groups (P < 0.01). The level of superoxide dismutase was significantly increased in the 0.5 Gy × 6 group (P < 0.01). The levels of 8-OHdG were significantly increased in all dose groups (P < 0.05). In both the 0.2 Gy × 6 and 0.5 Gy × 6 groups, the expression levels of γ-H2AX and p-NF-κB p65 were significantly increased (P < 0.05), and the levels of IκBα were significantly decreased (P < 0.05). Conclusion Low-dose fractionated X-ray radiation can induce senescence and cause alterations in oxidative stress, oxidative damage, and the levels of NF-κB pathway proteins in L02 hepatocytes.

Objective To understand the impact of bed-making manipulation on the air surrounding bed units in hemodialysis room,evaluate the effectiveness of routine terminal disinfection,and provide scientific basis for optimi-zing infection control measures.Methods Air specimens(pre-bed-making group)and environmental object surface specimens(pre-terminal disinfection group)around bed units were collected when hemodialysis was about to be fi-nished.Air specimens after bed-making(bed-making group)and environmental object surface specimens after ter-minal disinfection(terminal disinfection group)were also collected.Bacterial colonies were counted and identified.Results A total of 714 air specimens were collected from 238 bed units of 45 hemodialysis units before and during bed-making.The average bacterial colony count during bed-making was higher than that before bed-making([2.72±3.43]CFU/plate vs[0.69±1.50]CFU/plate,P＜0.05).The qualified rate of microbial colony count before bed-making was higher than that during bed-making(96.64％vs 64.71％,P＜0.05).A total of 450 environmental ob-ject surface specimens from 90 bed units of 45 hemodialysis units were collected before and after terminal disinfec-tion.The average bacterial colony count before terminal disinfection was higher than that after terminal disinfection([8.18±20.6]CFU/cm2 vs[1.49±3.44]CFU/cm2.P＜0.05).The qualified rate of microbial colony count after terminal disinfection was higher than that before terminal disinfection(98.22％vs 92.44％,P＜0.05).The micro-organisms in the air and environment were mainly coagulase negative Staphylococcus.Conclusion Bed-making has a certain impact on the air microorganisms around the bed units,and terminal disinfection can reduce the bacterial co-lony count of the environment.It is necessary to pay attention to the cleaning and disinfection of the environment for medical treatment,and carry out bed-making manipulation under clear condition to minimize the risk of infection.

Objective To explore the relationship between the ferroptosis-related molecules heme oxygenase-1(HMOX1)and mitogen-activated protein kinase 14(MAPK14)with the onset and prognosis of acute lung injury(ALI)in children with sepsis.Methods A total of 102 children with sepsis were selected,including 54 in the ALI group and 48 in the non-ALI group.Clinical data,laboratory tests,organ function scores and serum levels of HMOX1 and MAPK14 were compared between the two groups.The mortality rates of children with different levels of HMOX1 and MAPK14 at 28-day and 90-day were analyzed.Results Compared with the non-ALI group,procalcitonin(PCT),lactate(Lac),pediatric organ dysfunction Logistic-2 score(PELOD-2),pediatric risk of mortality score version 3(PRISM III)and sequential organ failure assessment(SOFA)scores were increased in the ALI group(P＜0.05).Serum levels of HMOX1 and MAPK14 were significantly higher in the ALI group than those in the non-ALI group(P＜0.05).HMOX1 and MAPK14 showed good predictive value for the occurrence of ALI in sepsis patients,with AUC values of 0.872(95%CI:0.791-0.930)and 0.825(95%CI:0.737-0.893),and the optimal cutoff values were 3.1 μg/L and 3.8 μg/L,respectively.After grouping by the cutoff values of HMOX1 and MAPK14,there were no significant differences in the 28-day and 90-day mortality rates in children with different levels of HMOX1 and MAPK14(P＞0.05).Conclusion The expression levels of serum HMOX1 and MAPK14 increase in the early stage of sepsis-related ALI,which may serve as biomarkers for the onset of ALI,and they have no significant impact on the prognosis of children.

Objective:Bidirectional causal associations of 41 cytokines with atopic dermatitis(AD)were explored based on a Mendelian randomization(MR)approach.Methods:Pooled data from genome wide association study(GWAS)of 41 cytokines and AD were utilized for instrumental variable(IV)screening,and single nucleotide polymorphism(SNP)affecting the results of MR analyses was excluded by the MR-PRESSO outlier test as well as by the MR Steiger filtering method.Two-sample bidirectional MR analyses were performed using inverse variance weighting(IVW),MR-Egger regression,and weighted median methods(WM).MR-Egger intercept term test and Cochran's Q test were performed to test the pleiotropy and heterogeneity of IV,and MR results were visu-alized by scatterplots,funnel plots,and leave-one-out plots.Results:Forward MR analysis showed that MIG(IVW:OR=0.89;95%CI:0.81～0.97;P=0.006)reduced the risk of AD development.In contrast,IL-5(IVW:OR=1.17;95%CI:1.01～1.36;P=0.042)and IL-18(MR Egger:OR=1.17;95%CI:1.03～1.33;P=0.030)increased the risk of AD development.Inverse MR analysis showed a potential causal association between AD and increased MIG(IVW:Beta=0.10;95%CI:0.02～0.17;P=0.014).None of the sensitivity analyses indicated pleiotropy and heterogeneity of the included IV.Conclusion:MIG may be an important marker in the progression of AD with a potential bidirectional causal association with risk of morbidity.IL-5 and IL-18 have a potential positive causal association for AD.

Objective To understand the impact of bed-making manipulation on the air surrounding bed units in hemodialysis room,evaluate the effectiveness of routine terminal disinfection,and provide scientific basis for optimi-zing infection control measures.Methods Air specimens(pre-bed-making group)and environmental object surface specimens(pre-terminal disinfection group)around bed units were collected when hemodialysis was about to be fi-nished.Air specimens after bed-making(bed-making group)and environmental object surface specimens after ter-minal disinfection(terminal disinfection group)were also collected.Bacterial colonies were counted and identified.Results A total of 714 air specimens were collected from 238 bed units of 45 hemodialysis units before and during bed-making.The average bacterial colony count during bed-making was higher than that before bed-making([2.72±3.43]CFU/plate vs[0.69±1.50]CFU/plate,P＜0.05).The qualified rate of microbial colony count before bed-making was higher than that during bed-making(96.64％vs 64.71％,P＜0.05).A total of 450 environmental ob-ject surface specimens from 90 bed units of 45 hemodialysis units were collected before and after terminal disinfec-tion.The average bacterial colony count before terminal disinfection was higher than that after terminal disinfection([8.18±20.6]CFU/cm2 vs[1.49±3.44]CFU/cm2.P＜0.05).The qualified rate of microbial colony count after terminal disinfection was higher than that before terminal disinfection(98.22％vs 92.44％,P＜0.05).The micro-organisms in the air and environment were mainly coagulase negative Staphylococcus.Conclusion Bed-making has a certain impact on the air microorganisms around the bed units,and terminal disinfection can reduce the bacterial co-lony count of the environment.It is necessary to pay attention to the cleaning and disinfection of the environment for medical treatment,and carry out bed-making manipulation under clear condition to minimize the risk of infection.

Objective:Bidirectional causal associations of 41 cytokines with atopic dermatitis(AD)were explored based on a Mendelian randomization(MR)approach.Methods:Pooled data from genome wide association study(GWAS)of 41 cytokines and AD were utilized for instrumental variable(IV)screening,and single nucleotide polymorphism(SNP)affecting the results of MR analyses was excluded by the MR-PRESSO outlier test as well as by the MR Steiger filtering method.Two-sample bidirectional MR analyses were performed using inverse variance weighting(IVW),MR-Egger regression,and weighted median methods(WM).MR-Egger intercept term test and Cochran's Q test were performed to test the pleiotropy and heterogeneity of IV,and MR results were visu-alized by scatterplots,funnel plots,and leave-one-out plots.Results:Forward MR analysis showed that MIG(IVW:OR=0.89;95%CI:0.81～0.97;P=0.006)reduced the risk of AD development.In contrast,IL-5(IVW:OR=1.17;95%CI:1.01～1.36;P=0.042)and IL-18(MR Egger:OR=1.17;95%CI:1.03～1.33;P=0.030)increased the risk of AD development.Inverse MR analysis showed a potential causal association between AD and increased MIG(IVW:Beta=0.10;95%CI:0.02～0.17;P=0.014).None of the sensitivity analyses indicated pleiotropy and heterogeneity of the included IV.Conclusion:MIG may be an important marker in the progression of AD with a potential bidirectional causal association with risk of morbidity.IL-5 and IL-18 have a potential positive causal association for AD.

Objective To explore the relationship between the ferroptosis-related molecules heme oxygenase-1(HMOX1)and mitogen-activated protein kinase 14(MAPK14)with the onset and prognosis of acute lung injury(ALI)in children with sepsis.Methods A total of 102 children with sepsis were selected,including 54 in the ALI group and 48 in the non-ALI group.Clinical data,laboratory tests,organ function scores and serum levels of HMOX1 and MAPK14 were compared between the two groups.The mortality rates of children with different levels of HMOX1 and MAPK14 at 28-day and 90-day were analyzed.Results Compared with the non-ALI group,procalcitonin(PCT),lactate(Lac),pediatric organ dysfunction Logistic-2 score(PELOD-2),pediatric risk of mortality score version 3(PRISM III)and sequential organ failure assessment(SOFA)scores were increased in the ALI group(P＜0.05).Serum levels of HMOX1 and MAPK14 were significantly higher in the ALI group than those in the non-ALI group(P＜0.05).HMOX1 and MAPK14 showed good predictive value for the occurrence of ALI in sepsis patients,with AUC values of 0.872(95%CI:0.791-0.930)and 0.825(95%CI:0.737-0.893),and the optimal cutoff values were 3.1 μg/L and 3.8 μg/L,respectively.After grouping by the cutoff values of HMOX1 and MAPK14,there were no significant differences in the 28-day and 90-day mortality rates in children with different levels of HMOX1 and MAPK14(P＞0.05).Conclusion The expression levels of serum HMOX1 and MAPK14 increase in the early stage of sepsis-related ALI,which may serve as biomarkers for the onset of ALI,and they have no significant impact on the prognosis of children.