Background and purpose:Intracellular deubiquitylating enzymes,such as ubiquitin-specific peptidase 2(USP2),play a pivotal role in regulating protein degradation and cellular homeostasis by modulating protein ubiquitin deconjugation,which have been implicated in the proliferation and survival of multiple myeloma(MM)cells.Targeting the inhibition of USP2 activity in MM cells might modulate their biological behavior.This study aimed to investigate regulatory effects of the leukotriene receptor antagonist montelukast sodium on USP2 in MM cells and its subsequent biological effects.Methods:An in vitro deubiquitination reaction system was established using purified USP2 protein and its substrate,the glutathione S-transferase(GST)tagged ubiquitin A-52 residue ribosomal protein fusion product(UbA52),known as GST-UbA52 protein.This system was used to characterize inhibitory effects of montelukast sodium on USP2 deubiquitinase activity.The MM cell lines MM1.S and H929 were used as in vitro models.Cellular thermal shift assay(CETSA)was subsequently employed to test interaction mode between montelukast sodium and USP2 in MM cells.Western blot assay was applied to detect expression levels of USP2 and its targeting regulators,including cell cycle supervisors cyclin D1(CCND1)and cyclin A1(CCNA1),classical signaling transducer KRAS and glucose regulated protein 78kD(GRP78),as well as apoptotic molecule C/EBP-homologous protein(CHOP)in MM1.S and H929 cells before and after the treatment with different concentrations of montelukast sodium.MM cells with either overexpression(H929-OE,MM1.S-OE)or knockdown(H929-LE,MM1.S-LE)of USP2 were generated using a lentiviral vector.Cell counting kit-8(CCK-8)and flow cytometry were utilized to detect the proliferation and apoptotic rates of H929-OE,MM1.S-OE,H929-LE and MM1.S-LE cells treated with montelukast sodium.Results:Montelukast sodium was found to inhibit USP2 mediated degradation of GST-UbA52 protein in a concentration-dependent manner,with a half inhibitory concentration(IC50)of 3.814 μmol/L.Additionally,montelukast sodium significantly enhanced the thermal stability of USP2 at temperatures of 49.1,53.2 and 56.4℃.It was also shown that montelukast sodium could down-regulate expressions of CCND1,CCNA1 and KRAS,while increase levels of GRP78 and CHOP in MM1.S and H929 cells.Furthermore,after treating with 40 μmol/L montelukast sodium for 24 h,the proliferation inhibition and apoptotic rate of H929-OE cells reached to(37.68±1.10)%and(18.99±0.26)%,while the proliferation inhibition and apoptotic rate of MM1.S-OE cells reached to(24.48±0.49)%and(33.29±0.75)%,which were significantly lower than those in H929 and MM1.S cells[H929:(57.19±1.93)%and(45.65±0.24)%;MM1.S:(50.04±0.53)%and(40.25±0.91)%;P＜0.05,n=3].Conversely,the proliferation inhibition and apoptotic rates of H929-LE and MM1.S-LE cells were significantly higher[H929-LE-1#:(80.70±1.60)%and(89.08±0.49)%;H929-LE-2#:(75.30±3.80)%and(82.41±1.07)%;MM1.S-LE-1#:(70.64±0.84)%and(67.63±0.21)%;MM1.S-LE-2#:(68.47±1.32)%and(85.90±0.18)%;P＜0.05,n=3].Conclusion:Montelukast sodium can target ubiquitin proteasome regulator USP2 and inhibit its deubiquitylating activity,which may modulate USP2 directing protein and trigger endoplasmic reticulum stress to induce cell cycle arrest and apoptosis in MM cells.

Background and purpose:Intracellular deubiquitylating enzymes,such as ubiquitin-specific peptidase 2(USP2),play a pivotal role in regulating protein degradation and cellular homeostasis by modulating protein ubiquitin deconjugation,which have been implicated in the proliferation and survival of multiple myeloma(MM)cells.Targeting the inhibition of USP2 activity in MM cells might modulate their biological behavior.This study aimed to investigate regulatory effects of the leukotriene receptor antagonist montelukast sodium on USP2 in MM cells and its subsequent biological effects.Methods:An in vitro deubiquitination reaction system was established using purified USP2 protein and its substrate,the glutathione S-transferase(GST)tagged ubiquitin A-52 residue ribosomal protein fusion product(UbA52),known as GST-UbA52 protein.This system was used to characterize inhibitory effects of montelukast sodium on USP2 deubiquitinase activity.The MM cell lines MM1.S and H929 were used as in vitro models.Cellular thermal shift assay(CETSA)was subsequently employed to test interaction mode between montelukast sodium and USP2 in MM cells.Western blot assay was applied to detect expression levels of USP2 and its targeting regulators,including cell cycle supervisors cyclin D1(CCND1)and cyclin A1(CCNA1),classical signaling transducer KRAS and glucose regulated protein 78kD(GRP78),as well as apoptotic molecule C/EBP-homologous protein(CHOP)in MM1.S and H929 cells before and after the treatment with different concentrations of montelukast sodium.MM cells with either overexpression(H929-OE,MM1.S-OE)or knockdown(H929-LE,MM1.S-LE)of USP2 were generated using a lentiviral vector.Cell counting kit-8(CCK-8)and flow cytometry were utilized to detect the proliferation and apoptotic rates of H929-OE,MM1.S-OE,H929-LE and MM1.S-LE cells treated with montelukast sodium.Results:Montelukast sodium was found to inhibit USP2 mediated degradation of GST-UbA52 protein in a concentration-dependent manner,with a half inhibitory concentration(IC50)of 3.814 μmol/L.Additionally,montelukast sodium significantly enhanced the thermal stability of USP2 at temperatures of 49.1,53.2 and 56.4℃.It was also shown that montelukast sodium could down-regulate expressions of CCND1,CCNA1 and KRAS,while increase levels of GRP78 and CHOP in MM1.S and H929 cells.Furthermore,after treating with 40 μmol/L montelukast sodium for 24 h,the proliferation inhibition and apoptotic rate of H929-OE cells reached to(37.68±1.10)%and(18.99±0.26)%,while the proliferation inhibition and apoptotic rate of MM1.S-OE cells reached to(24.48±0.49)%and(33.29±0.75)%,which were significantly lower than those in H929 and MM1.S cells[H929:(57.19±1.93)%and(45.65±0.24)%;MM1.S:(50.04±0.53)%and(40.25±0.91)%;P＜0.05,n=3].Conversely,the proliferation inhibition and apoptotic rates of H929-LE and MM1.S-LE cells were significantly higher[H929-LE-1#:(80.70±1.60)%and(89.08±0.49)%;H929-LE-2#:(75.30±3.80)%and(82.41±1.07)%;MM1.S-LE-1#:(70.64±0.84)%and(67.63±0.21)%;MM1.S-LE-2#:(68.47±1.32)%and(85.90±0.18)%;P＜0.05,n=3].Conclusion:Montelukast sodium can target ubiquitin proteasome regulator USP2 and inhibit its deubiquitylating activity,which may modulate USP2 directing protein and trigger endoplasmic reticulum stress to induce cell cycle arrest and apoptosis in MM cells.

[摘 要] 目的：探讨程序性死亡受体-1（PD-1）单抗联合顺铂或吉西他滨在KRAS基因突变非小细胞肺癌（NSCLC）A549细胞移植瘤小鼠模型治疗中的作用。方法：构建免疫系统-肿瘤双人源化A549细胞小鼠移植瘤模型，将60只小鼠按随机数字表法分成6组（10只/组），分别为对照组（200 μL/kg PBS）、PD-1单抗组（20 mg/kg PD-1单抗）、顺铂组（3 mg/kg顺铂）、PD-1单抗+顺铂组（20 mg/kg PD-1单抗+3 mg/kg顺铂）、吉西他滨组（30 mg/kg吉西他滨）和PD-1单抗+吉西他滨组（20 mg/kg PD-1单抗+30 mg/kg吉西他滨）。TUNEL和DAPI双染色法检测移植瘤组织中细胞凋亡水平，测量移植瘤体积和质量并计算肿瘤生长抑制率，免疫组化法检测移植瘤微血管密度（MVD）。结果：成功构建免疫系统-肿瘤双人源化NSCLC A549细胞小鼠移植瘤模型，PD-1单抗+顺铂组移植瘤的细胞凋亡率、肿瘤生长抑制率均最高，移植瘤体积、质量和MVD均最小，与其他5组小鼠比较差异均有统计学意义（均P<0.05）。结论：顺铂与PD-1单抗具有协同活性，而吉西他滨拮抗PD-1单抗的治疗作用。提示PD-1单抗联合顺铂对KRAS突变NSCLC A549细胞移植瘤小鼠的疗效更好。

Objective To explore the effect of neutrophil to lymphocyte ratio(NLR)and other related in-dicators on the prognosis of advanced non-small cell lung cancer patients treated with programmed death 1(PD-1)inhibitor and construct a nomogram prediction model.Methods A total of 198 patients with advanced non-small cell lung cancer who received PD-1 inhibitor treatment in the hospital from February 2020 to April 2022 were selected and followed up to August 2022.According to the clinical outcome,they were divided into the death group(46 cases)and the survival group(152 cases).The clinical data of the death group and the survival group were recorded,and the prognostic factors of advanced non-small cell lung cancer patients trea-ted with PD-1 inhibitor were analyzed.Receiver operating characteristic(ROC)curve was used to analyze the predictive value of NLR,platelet to lymphocyte ratio(PLR)and lymphocyte to monocyte ratio(LMR)for the prognosis of patients.Multivariate Logistic regression model was used to analyze the independent risk factors affecting the prognosis of patients.A prediction nomogram model for the prognosis of patients was construc-ted using R software 4.0"rms"package,and the calibration curve was used to internally validate the nomo-gram prediction model.Results Compared with the survival group,the proportion of smoking,TNM stageⅣ,ECOG score 2,and NLR,PLR,LMR were higher(P<0.05).The area under the curve of NLR,PLR and LMR were 0.707,0.793 and 0.819,respectively,and the optimal cut-off value were 4.72%,179.21%and 3.44%,respectively.Smoking,TNM stage,ECOG score,NLR,PLR,and LMR were independent risk factors for the prognosis of advanced non-small cell lung cancer patients treated with PD-1 inhibitor(P<0.05).The internal validation results show that the nomogram inhibitor treatment of PD-1 model prediction the prognosis of patients with advanced non-small cell lung cancer C-index was 0.847(95%CI 0.769-0.902),the calibra-tion curve tends to be the ideal curve.The threshold value of the nomogram model for predicting the prognosis of patients with advanced non-small cell lung cancer treated with PD-1 inhibitor was>0.22.The nomogram prediction model provided a net clinical benefit,and the net clinical benefit was higher than that of smoking,TNM stage,ECOG score,NLR,PLR and LMR.Conclusion Based on smoking,TNM stage,ECOG score,NLR,PLR,and LMR,a nomogram prediction model for the prognosis of advanced non-small cell lung cancer patients treated with PD-1 inhibitor is constructed,which has important clinical application value.

ObjectiveTo explore the activating effects of ten important effective components in seven medicinal and edible substances on human pregnane X receptor （PXR）， including Glycyrrhizae Radix et Rhizoma （liquiritin and glycyrrhizic acid）， Houttuyniae Herba （quercetin and houttuyfonate）， Prunellae Spica （rosmarinic acid）， Cassiae Semen （aurantio-obtusin）， Poria （pachymic acid）， Lilii Bulbus （Lilium brownii saponin and colchicine）， and Lycii Fructus （Lycium barbarum polysaccharide） and screen potentially toxic components. MethodCell counting kit-8 （CCK-8） assay was used to investigate the cytotoxic effect of liquiritin， glycyrrhizic acid， quercetin， houttuyfonate， rosmarinic acid， pachymic acid， aurantio-obtusin， and colchicine （10， 20， and 50 μmol·L^-1）， and L. brownii saponin and L. barbarum polysaccharide （10， 20， and 50 mg·L^-1） on normal human hepatocyte cell line （L02）. The release of lactate dehydrogenase （LDH） in L02 cells after drug treatments was detected by the biochemical analyzer. The apoptosis induced by ten effective components was explored by Hoechst 33342 staining. The secreted luciferase reporter system was used to co-transfect the PXR expression vector and reporter gene vector containing cytochrome P450 3A4 （CYP3A4） transcriptional regulatory region into L02 cells， with 10 μmol·L^-1 rifampicin （RIF） as a positive control. After treated with liquiritin， glycyrrhizic acid， quercetin， houttuyfonate， rosmarinic acid， aurantio-obtusin， pachymic acid， and colchicine （5， 10， and 20 μmol·L^-1） and L. brownii saponin and L. barbarum polysaccharide （5， 10， and 20 mg·L^-1） for 24 h， the cells were tested for secreted luciferase activity. ResultCompared with the control group， colchicine， L. brownii saponin， and quercetin decreased the cell viability （P<0.05， P<0.01）. Compared with the control group， quercetin， rosmarinic acid， glycyrrhizic acid， colchicine， aurantio-obtusin， and pachymic acid increased the release rate of LDH in L02 cells （P<0.05， P<0.01）. The proportion of hyperchromatic nuclei increased gradually after rosmarinic acid， liquiritin， and L. barbarum polysaccharide treatments as compared with the control group （P<0.05， P<0.01）. In terms of co-transfection of pcDNA3.1-PXR and pGLuc-CYP3A4 into L02 cells， compared with the control group， aurantio-obtusin and pachymic acid showed activating effects on PXR （P<0.05）， whereas liquiritin and glycyrrhizic acid showed inhibitory effects （P<0.05）. ConclusionThe findings suggest that when medicinal and edible substances are taken for a long time， attention should be paid to their influence on drug-metabolizing enzymes and possible interactions， so as to improve their safety.

Objective:To explore the effect of Notch1 signaling on regulatory T cells and its roles in vascular damage in patients with Kawasaki disease (KD).Methods:A total of 42 children with KD were enrolled in the present study from March 2019 to June 2020, as 32 age-matched healthy children were recruited as control. The proportions of CD4 +CD25 hiFoxp 3+ regulatory T cells (Treg) and expressions of transcription factor forkhead box protein 3 (Foxp3), cytotoxic T lymphocyte associated antigen-4 (CTLA4), glucocorticoid-induced tumor necrosis factor receptor (GITR), and Notch1 protein were evaluated by flow cytometry. Chromatin immunoprecipitation was conducted to detect acetylation level of histone H4 (H4Ac) associated with the promoter of Foxp3 gene and its binding abilities of Notch1 intracellular domain 1 (NICD1), recombination signal binding protein for immunoglobulin kappa J region (RBP-J) and p300 in CD4 + T cells. Transcription levels of Foxp3, presenilin 1 (PSEN1), mastermind like transcriptional coactivator 1 (MAML1), and RBP-J in CD4 + T cells were determined by real-time polymerase chain reaction (PCR). Concentrations of interleukin (IL)-10 and transforming growth factor-β (TGF-β) in plasma and culture supernatant stimulated with Jagged1 were measured by enzyme linked immunosorbent assay. Independent-sample t-test, Pearson correlation analysis was used as the statistical method in this study. Results:① The frequencies of Treg in acute KD patients decreased significantly [(4.3±1.5)% vs (7.9±2.9)%; t=6.41, P<0.001], as protein levels of Foxp3, CTLA4 and GITR and concentrations of IL-10 and TGF-β in plasma reduced remarkably in acute KD patients ( t=6.87, P<0.001; t=4.26, P<0.001; t=7.88, P<0.001; t=8.42, P<0.001; t=13.01, P<0.001). All parameters afore-mentioned in patients combined with coronary artery lesions (CAL) were lower than those of patients without coronary artery lesions (NCAL) ( t=5.83, P<0.001; t=3.83, P<0.001; t=3.28, P=0.002; t=5.05, P<0.001; t=5.96, P<0.001; t=5.17, P<0.001), and increased after therapy ( t=7.13, P<0.001; t=6.10, P<0.001; t=4.31, P<0.001; t=6.55, P<0.001; t=7.40, P<0.001; t=7.84, P<0.001). ② H4Ac associated with promoter of Foxp3 gene and the binding abilities of NICD1 and p300 in acute KD patients were lower than those of the controls ( t=10.25, P<0.001; t=6.93, P<0.001; t=6.75, P<0.001), and increased remarkably after therapy ( t=7.72, P<0.001; t=4.16, P<0.001; t=5.76, P<0.001). Meanwhile, the three items in CAL group were found to be less than those of NCAL group ( t=6.08, P<0.001; t=2.66, P=0.011; t=6.02, P<0.001). Pearson correlation analysis showed a positive correlation between H4Ac associated with Foxp3 promoter and its mRNA level in acute KD patients ( r=0.47, P<0.001). No statistical significant difference about the binding ability of RBP-J with Foxp3 promoter were found among the groups ( t=0.57, P>0.05; t=0.61, P>0.05; t=1.20, P>0.05). ③ Protein level of Notch1 and the expressions of PSEN1, MAML1 and RBP-J mRNA in CD4 + T cells from acute KD patients were down-regulated remarkably ( t=5.28, P<0.001; t=6.31, P<0.001; t=11.78, P<0.001; t=8.06, P<0.001), and restored after therapy ( t=4.77, P<0.001; t=6.43, P<0.001; t=11.95, P<0.001; t=7.79, P<0.001). In parallel, the four indexes aforementioned of CAL group were lower than those of NCAL group ( t=3.16, P=0.003; t=4.13, P<0.001; t=5.42, P<0.001; t=4.05, P<0.001). Upon rhJagged1 stimulation for 48 hours, H4Ac level of Foxp3 promoter and its binding abilities with NICD1 and p300 in CD4 + T cells in KD patients and control group was significantly higher than those of untreated group [(KD: t=15.36, P<0.001; t=7.25, P<0.001; t=14.29, P<0.001), (Ctrl: t=7.87, P<0.001; t=5.71, P<0.001; t=8.74, P<0.001)], as the binding ability of RBP-J with Foxp3 promoter increased slightly without statistically significant difference (KD: t=1.11, P>0.05; Ctrl: t=1.37, P>0.05). Simultaneously, H4Ac level of Foxp3 promoter and its binding abilities with NICD1 and p300 in KD group were still lower than those of the control group after stimulation ( t=3.86, P<0.001; t=3.42, P=0.001; t=2.85, P=0.006). ④ After incubation of PBMC from heathy children with KD serum, the proportion of Treg cells, protein level of Foxp3 and expressions of Notch1 and RBP-J in CD4 + T cells in the group treated with IVIG increased significantly compared with the untreated group ( t=7.10, P<0.001; t=10.16, P<0.001; t=8.06, P<0.001; t=9.77, P<0.001), as well as H4Ac level of Foxp3 promoter and its binding abilities with NICD1 in the group treat with IVIG were also higher than the latter ( t=7.24, P<0.001; t=8.24, P<0.001). Conclusion:Insufficiency and impaired function of Treg caused by aberrant Notch1 signaling may be the important factor contributing to immune dysfunction and vascular damage in KD.

Objective:To investigate the changes and significance of granulocyte-like myeloid-derived suppressor cells (G-MDSC) in the acute phage of Kawasaki disease (KD).Methods:Forty-two children with acute KD were enrolled in the present study and 32 age-matched healthy children were selected as control group. The proportion of HLA-DR -CD11b + CD33 + CD14 -CD15 + G-MDSC, the concentration of reactive oxygen species (ROS) and the expression of arginase-1 (Arg-1), programmed death-ligand 1 (PD-L1), cytotoxic T lymphocyte associated protein 4 (CTLA4), glycoprotein 130 (gp130) and phosphorylated signal transducer and activator of transcription 3 (pSTAT3) at protein level were detected by flow cytometry. Quantitative real-time PCR was used to measure the expression of inducible nitric oxide synthase (iNOS), interferon regulatory factor 8 (IRF-8), IL-6 receptor α subunit (IL-6Rα), granulocyte colony-stimulating factor receptor (G-CSFR), CCAAT/enhancer binding protein β (C/EBPβ), suppressor of cytokine signaling 1 (SOCS1) and SOCS3 at mRNA level in G-MDSC. Chromatin immunoprecipitation was performed to detect the acetylation of histone H3 at the promoters of SOCS1 and SOCS3 genes. Plasma concentrations of IL-6 and granulocyte colony-stimulating factor (G-CSF) and protein levels of IL-10, transforming growth factor-β (TGF-β) and nitric oxide (NO) in the culture supernatant of G-MDSC stimulated with LPS were measured by ELISA. Results:(1) Compared with the control group, the proportion of HLA-DR -CD11b + CD33 + CD14 -CD15 + G-MDSC as well as the concentration of ROS and the expression of inhibitory molecules (Arg-1, PD-L1 and CTLA4) in G-MDSC increased significantly in patients with acute KD ( P<0.05). Moreover, the concentrations of IL-10 and TGF-β in culture supernatant of G-MDSC were also higher than those of the control group after stimulation with lipopolysaccharide for 48 h ( P<0.05). All of the seven afore-mentioned indexes in KD patients with coronary artery lesion (CAL group ) were lower than those in patients without coronary artery lesion (NCAL group) ( P<0.05), and restored to some extent after IVIG therapy ( P<0.05). There were no statistical differences in iNOS expression or NO concentration in culture supernatant of G-MDSC among different groups ( P<0.05). (2) Plasma concentrations of IL-6 and G-CSF, and the expression of IL-6Rα, gp130, G-CSFR, pSTAT3 and C/EBPβ increased remarkably during acute phase of KD ( P<0.05). The expression of IRF-8 at transcription level in patients with acute KD was found to be lower than that of healthy controls ( P<0.05), and restored significantly after IVIG therapy ( P<0.05). Moreover, the plasma concentrations of IL-6 and G-CSF and the expression of IL-6Rα, gp130, G-CSFR and IRF-8 in the CAL group were higher than those in the NCAL group ( P<0.05), while the expression of pSTAT3 and C/EBPβ was lower in the CAL group ( P<0.05), which were restored by IVIG therapy ( P<0.05). (3) In patients with acute KD, the expression of SOCS1 and SOCS3 at mRNA level and histone acetylation at the promoters of SOCS1 and SOCS3 genes were reduced significantly in comparison with those in healthy controls ( P<0.05) , but were increased remarkably after IVIG treatment( P<0.05). The four indexes were higher in the CAL group than in the NCAL group ( P<0.05). Pearson correlation analysis showed the expression of SOCS1 and SOCS3 was negatively correlated with the protein level of pSTAT3 in G-MDSC of patients with acute KD ( r=-0.46 and -0.32, P<0.05). Conclusions:Changes in the number and function of G-MDSC caused by aberrant histone acetylation at SOCS1 and SOCS3 genes might contribute to the immune dysfunction and vascular damage in patients with KD.

Objective:To investigate the changes of CD8 + CD28 - regulatory T cells (Treg) and its role in the pathogenesis of Kawasaki disease (KD). Methods:A total of 48 children with KD were enrolled in the present study from June 2019 to December 2021. Blood samples were collected from them during acute phage of KD and after intravenous immunoglobulin (IVIG) treatment. Another 32 age-matched healthy children were recruited as control group. The proportions of CD8 + CD28 -Treg cells and the expression of programmed cell death protein 1 (PD-1), factor associated suicide ligand (FasL), inducible T-cell co-stimulator ligand (ICOSL), CD80 and CD86 protein were evaluated by flow cytometry. The expression of Helios, perforin, granzyme B, immunoglobulin-like transcript 3 (ILT3) and ILT4 at the transcription level was measured by real-time PCR. Concentrations of IL-10 and TGF-β in the culture supernatants of CD8 + CD28 -Treg cells stimulated with activated CD4 + T cells were measured by ELISA. Results:⑴ The proportions of CD8 + CD28 -Treg cells and the expression of Helios in patients with acute KD were higher than those in the control group ( P<0.05), and reduced remarkably after IVIG therapy ( P<0.05). The two afore-mentioned indexes were lower in patients combined with coronary artery lesion (CAL) than in those without coronary artery lesion (NCAL) ( P<0.05). ⑵ Compared with the control group, the patients with acute KD showed increased expression of FasL, PD-1, ICOSL and perforin in CD8 + CD28 -Treg cells ( P<0.05). The concentrations of IL-10 and TGF-β1 in the culture supernatants of CD8 + CD28 -Treg cells from patients with acute KD were lower than those in the control group after stimulation with activated CD4 + T cells ( P<0.05), which restored to some extent after IVIG treatment ( P<0.05). All of the six above-mentioned indexes in the CAL group were found to be lower than those in the NCAL group ( P<0.05). There were slight differences in granzyme B expression between different groups ( P>0.05). (3) In comparison with the healthy controls, the patients with acute KD showed overexpressed co-stimulatory molecules such as CD80 and CD86 on CD14 + cells ( P<0.05) and up-regulated expression of inhibitory molecules ILT3 and ILT4 ( P<0.05), which were restored remarkably after IVIG treatment ( P<0.05). Furthermore, the expression of CD80 and CD86 at protein level increased in the CAL group than in the NCAL group ( P<0.05), while the expression of ILT3 and ILT4 at transcriptional level decreased in the CAL group ( P<0.05). Conclusions:Relative insufficiency and impaired function of CD8 + CD28 -Treg cells might be one of the important factors resulting in immune dysfunction and vascular damage in KD patients.

Objective:To analyze the incidence, biochemical and molecular characteristics, and gene mutation spectrum of neonatal methylmalonic acidemia (MMA) in Shaanxi province.Methods:This study involved 146 152 newborns undergoing neonatal screening for methylmalonic acidemia by tandem mass spectrometry in Northwest Women's and Children's Hospital from January 2014 and December 2019. Clinical manifestations and follow-up data of newborns diagnosed with MMA and their acylcarnitine profiles and gene mutations were analyzed. According to whether they had elevated homocysteine or not, these patients were divided into two groups, the complicated group and the isolated MMA group. The control neonates were those excluded from having methylmalonic acid by re-examination. Kruskal-Wallis and Mann-Whitney U test was conducted for statistical analysis. Results:(1) Twenty-one cases of MMA were confirmed with an incidence of 1/6 960, including 11 cases (52.4%) of isolated MMA (isolated MMA group) and 10 (47.6%) complicated by elevated homocysteine (complicated group). Eight patients in the isolated group had symptoms within one month after birth, mainly feeding difficulties, vomiting, drowsiness, poor response and infection, and five died. Patients in the complicated group were all diagnosed before developing typical clinical symptoms, and no developmental abnormalities were reported during follow-up. (2) Blood propionyl carnitine and its ratios to acetylcarnitine and free carnitine in the isolated MMA and complicated groups were higher than those in the control group [ M (min-max), 9.26 (3.70-37.78) μmol/L and 7.27 μmol/L (3.58-13.62 μmol/L) vs 4.51 μmol/L (1.48-8.69 μmol/L), H=23.239; 1.12 (0.32-2.43) and 0.74 (0.36-1.90) vs 0.25 (0.09-0.45), H=47.061; 0.94 (0.12-1.92) and 0.56 (0.18-1.03) vs 0.17 (0.06-0.38), H=36.868; all P<0.001]. The blood methionine level in the complicated group was significantly lower than that in the isolated MMA group [7.64 μmol/L (3.40-19.25 μmol/L) vs 24.22 μmol/L (10.73-56.55 μmol/L), U=3.000, P<0.001]. (3) All 21 patients carried complex heterozygous mutations or homozygous mutations in pathogenic genes, including 15 distinct MMUT mutations and 13 distinct MMACHC mutations. In the isolated MMA group, the most common mutation was c.323G>A (p.Arg108His) in the MMUT gene with a positive rate of 13.6%, and an unreported mutation, c.1676+11A>G, with unidentified clinical significance, was also found. The most common mutations in the complicated group were c.609G>A (p.Trp203Ter) and c.567dupT (p.Ile190fs) in the MMACHC gene, and the positive rates were both 20.0%. Moreover, two unreported variants, c.430-2A>C and c.648_650delAGA (p.216_217delSEinsS), were detected and suspected to be pathogenic. Conclusions:MMA is not uncommon in Shaanxi province. Children with isolated MMA tend to be more severe clinically. The identification of hotspot mutations, including c.609G>A (p.Trp203Ter) and c.567dupT (p.Ile190fs) in MMACHC gene and c.323G>A (p.Arg108His) in MMUT gene, provides a foundation for further genetic screening, counseling, and prenatal diagnosis, and is conducive to reduce the mortality and disability rate of neonatal MMA.