OBJECTIVE: To investigate the effect of human adipose-derived mesenchymal stem cells (hASCs) exosomes on osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) extracted from osteoporotic mice, and to evaluate the effect of hASCs exosomes on preventing bone loss induced by estrogen deficiency. METHODS: hASCs exosomes were extracted by ultracentrifugation. The osteoporotic mice were established by bilateral ovariectomy (OVX). BMSCs were isolated from osteo-porotic mice and cultured for further analysis. In the experimental group, these BMSCs were exposed to an osteogenic induction medium supplemented with hASCs exosomes to evaluate their potential effects on osteogenesis. In contrast, the control group was treated with the same osteogenic induction medium, but without the addition of hASCs exosomes, to serve as a baseline comparison for the study. To comprehensively assess the osteogenic differentiation of BMSCs influenced by hASCs exosomes, alkaline phosphatase (ALP) staining, ALP activity quantitative analysis and quantitative reverse transcription polymerase chain reaction (qPCR) were performed. These evaluations provided critical insights into the role of hASCs exosomes in promoting osteoblast differentiation and bone formation in osteoporotic conditions. The fluorescence labeled hASCs exosomes were injected via the tail vein to observe the biodistribution of exosomes. Two weeks after OVX, the mice were divided into three groups: The experimental group consisted of estrogen-deficient mice receiving hASCs exosome injections; the negative control group consisted of estrogen-deficient mice receiving phosphate-buffered saline (PBS) injections; and the positive control group consisted of mice that underwent Sham surgery and received PBS injections.The injections were administered once every 3 days, for a total of 8 injections. Afterward, the femurs were collected from the mice, and micro-computed tomography (micro-CT) was performed to measure bone mineral density and conduct bone morphometric analysis. RESULTS: hASCs exosomes were successfully extracted using ultracentrifugation. After the induction by hASCs exosomes, ALP staining and ALP activity in the BMSCs extracted from osteoporotic mice were significantly enhanced, the expression of osteogenesis related genes in BMSCs were significantly up-regulated. More trabecular bone and higher bone mineral density were observed in estrogen-deficient mice injected with hASCs exosomes compared with estrogen-deficient mice injected with PBS, and there was no significant decrease in bone mineral density compared with the Sham operation group. CONCLUSION hASCs exosomes promoted the osteogenic differentiation of BMSCs extracted from osteoporotic mice. hASCs exosomes prevented bone loss induced by estrogen deficiency.
Animals ; Mesenchymal Stem Cells/cytology* ; Exosomes ; Estrogens/deficiency* ; Humans ; Osteogenesis ; Cell Differentiation ; Female ; Mice ; Osteoporosis/prevention & control* ; Ovariectomy ; Adipose Tissue/cytology* ; Cells, Cultured

OBJECTIVE: To identify the role of gene silencing or overexpression of Nemo-like kinase (NLK) during the process of neural differentiation of human mesenchymal stem cells (hBMSCs), and to explore the effect of NLK downregulation by transfection of small interfering RNA (siRNA) on promoting neuralized tissue engineered bone regeneration. METHODS: NLK-knockdown hBMSCs were established by transfection of siRNA (the experimental group was transfected with siRNA silencing the NLK gene, the control group was transfected with control siRNA and labeled as negative control group), and NLK-overexpression hBMSCs were established using lentivirus vector transfection technique (the experimental group was infected with lentivirus overexpressing the NLK gene, the control group was infected with an empty vector lentivirus and labeled as the empty vector group). After neurogenic induction, quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression of neural-related gene, and Western blot as well as immunofluorescence staining about several specific neural markers were used to evaluate the neural differentiation ability of hBMSCs.6-week-old male nude mice were divided into 4 groups: ① β-tricalcium phosphate (β-TCP) group, ② β-TCP+ osteogenic induced hBMSCs group, ③ β-TCP+ siRNA-negative control (siRNA-NC) transfection hBMSCs group, ④ β-TCP+ siRNA-NLK transfection hBMSCs group. Four weeks after the subcutaneous ectopic osteogenesis models were established, the osteogenesis and neurogenesis were detected by hematoxylin-eosin (HE) staining, Masson staining and tissue immunofluorescence assay. Statistical analysis was conducted by independent sample t test. RESULTS: After gene silencing of NLK by siRNA in hBMSCs, neural-related genes, including the class Ⅲ β-tubulin (TUBB3), microtubule association protein-2 (MAP2), soluble protein-100 (S100), nestin (NES), NG2 proteoglycan (NG2) and calcitonin gene-related peptide (CGRP), were increased significantly in NLK-knockdown hBMSCs compared with the negative control group(P < 0.05), and the expression levels of TUBB3 and MAP2 of the NLK silencing group were also increased. Oppositely, after NLK was overexpressed using lentivirus vector transfection technique, TUBB3, MAP2, S100 and NG2 were significantly decreased in NLK-overexpression hBMSCs compared with the empty vector group (P < 0.05), and the expression level of TUBB3 was also decreased. 4 weeks after the subcutaneous ectopic osteogenesis model was established, more mineralized tissues were formed in the β-TCP+ siRNA-NLK transfection hBMSCs group compared with the other three groups, and the expression of BMP2 and S100 was higher in the β-TCP+ siRNA-NLK transfection hBMSCs group than in the other groups. CONCLUSION Gene silencing of NLK by siRNA promoted the ability of neural differentiation of hBMSCs in vitro and promoted neuralized tissue engineered bone formation in subcutaneous ectopic osteogenic models in vivo in nude mice.
Bone Regeneration/genetics* ; Animals ; Mesenchymal Stem Cells/cytology* ; Humans ; RNA, Small Interfering/genetics* ; Tissue Engineering/methods* ; Cell Differentiation ; Mice, Nude ; Gene Silencing ; Mice ; Male ; Protein Serine-Threonine Kinases/genetics* ; Intracellular Signaling Peptides and Proteins/genetics* ; Transfection ; Cells, Cultured ; Lentivirus/genetics*

OBJECTIVE: To investigate the expression and possible regulatory mechanism of miR-34a in the lung tissue of neonatal rat model of bronchopulmonary dysplasia (BPD) induced by hyperoxia. METHODS: In the study, 80 newborn SD rats were randomly divided into hyperoxia group (FiO₂=60%) and air group (FiO₂=21%) within 2 hours after birth, 40 rats per group. Lung tissue samples of the SD rats in each group were extracted on the 1st, 7th, 14th and 21st days after birth, and the pathological changes of lung tissue were observed under light microscope after HE staining. The number of radial alveolar counts (RAC) and the mean alveolar diameter (MAD) and the thickness of alveolar septal thickness (AST) were measured to evaluate the development of alveoli. Real-time fluorescence quantitative PCR was used to detect the expression of miR-34a, angiopoietin-1 (Ang-1) and tyrosine kinase receptor-2 (Tie-2) in lung tissue of rats in hyperoxia group and air group at different time points. Enzyme-linked immunosorbent assay (ELISA) was used to detect the proteins expression of Ang-1 and Tie-2 in the lung tissues of the two groups at different time points. RESULTS: The weight of rats in the hyperoxia group on the 7th, 14th and 21st days after birth was significantly lower than that in the air group (P all < 0.05). With the prolongation of oxygen exposure, the number of alveoli decreased, the volume increased, the structure simplified, the alveolar cavity enlarged obviously and the alveolar septum thickened in the hyperoxia group. On the 7th, 14th and 21st days after birth, the RAC in the hyperoxia group was significantly lower than that in the air group (P all < 0.05). Compared with the air group, MAD and AST increased significantly on the 7th, 14th and 21st days after birth in the hyperoxia group, and the difference was statistically significant (P all < 0.05). The expression level of miR-34a in lung tissue of hyperoxia group was significantly higher than that of air group on the 7th, 14th and 21st days after birth, and the difference was statistically significant (P all < 0.05). Compared with the air group at the same time point, the expression levels of Ang-1 and Tie-2 mRNA and protein in the hyperoxia group were lower than those in the air group on the 14th and 21st days after birth (P all < 0.05). CONCLUSION The new BPD model of newborn SD rats can be successfully established by continuous exposure to 60% hyperoxia. The expression of miR-34a was up-regulated in the lung tissue of the new BPD model of neonatal rats. MiR-34a may play an important role in the occurrence and development of BPD by regulating Ang-1/Tie-2 signal pathway.
Animals ; MicroRNAs/metabolism* ; Bronchopulmonary Dysplasia/genetics* ; Hyperoxia/metabolism* ; Rats, Sprague-Dawley ; Animals, Newborn ; Rats ; Angiopoietin-1/genetics* ; Disease Models, Animal ; Receptor, TIE-2/genetics* ; Lung/pathology* ; Male

OBJECTIVE: To explore the changes of CKLF-like MARVEL transmembrane domain-containing 6 (CMTM6) and programmed death-ligand 1 (PD-L1) expression in gastric mucosal epithelial cells after Helicobacter pylori infection and the regulation of CMTM6 on PD-L1, and to analyze the mRNA expression differences before and after CMTM6 gene knock-out in helicobacter pylori infected gastric epithelial cells by microarray analysis. METHODS: The standard Helicobacter pylori strain ATCC 26695 was co-cultured with human gastric epithelial cell GES-1 for 6, 24 and 48 hours, and the mRNA and protein levels of CMTM6 and PD-L1 were detected by real-time quantitative PCR and Western blot. Using CRISPR/Cas9 to construct CMTM6 gene knockout plasmid and knockout CMTM6 gene of GES-1 cells. Helicobacter pylori was co-cultured with CMTM6 gene knockout and wild type GES-1 cells for 48 hours to detect PD-L1 transcription and protein level changes, and CMTM6 gene knockout GES-1 cells were treated with the proteasome inhibitor MG-132 to detect the changes in PD-L1 protein levels. Agilent Human ceRNA Microarray 2019 was used to detect the differentially expressed genes in CMTM6 gene knockout and wild-type GES-1 cells co-cultured with Hp for 48 hours, and the signal pathway of differentially expressed genes enrichment was analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) database. RESULTS: The mRNA and protein levels of CMTM6 and PD-L1 in GES-1 cells were significantly up-regulated after Helicobacter pylori infection, and CMTM6 mRNA was most significantly up-regulated 48 hours after infection. After CMTM6 gene knockout, the CD274 gene transcription level of Helicobacter pylori infected GES-1 cells did not change significantly, but PD-L1 protein level was significantly down-regulated, and the PD-L1 level increased after the application of proteasome inhibitor MG-132. After CMTM6 gene knockout, 67 genes had more than two times of differential expression. The transcription levels of TMEM68, FERMT3, GPR142, ATP6V1FNB, NOV, UBE2S and other genes were significantly down-regulated. The transcription levels of PCDHGA6, CAMKMT, PDIA2, NTRK3, SPOCK1 and other genes were significantly up-regulated. After CMTM6 gene knockout, ubiquitin-conjugating enzyme E2S (UBE2S) gene expression was significantly down-regulated, which might affect protein ubiquitination degradation. After CMTM6 gene knockout, adrenoceptor alpha 1B (ADRA1B), cholinergic receptor muscarinic 1 (M1), CHRM1, platelet activating factor receptor (PTAFR) gene expression was significantly up-regulated. CONCLUSION Helicobacter pylori infection up-regulates the expression level of CMTM6 in gastric mucosa cells, and CMTM6 can stabilize PD-L1 and maintain the protein level of PD-L1. CMTM6 gene knockout may affect biological behaviors such as protein ubiquitination and cell surface receptor expression.
Humans ; MARVEL Domain-Containing Proteins/metabolism* ; Helicobacter pylori/physiology* ; B7-H1 Antigen/genetics* ; Helicobacter Infections/metabolism* ; Epithelial Cells/metabolism* ; Gastric Mucosa/metabolism* ; Chemokines/metabolism* ; Cell Line ; Gene Knockout Techniques ; Myelin Proteins

OBJECTIVE: To investigate the biological activity and antitumor effect of pegylated recombinant human interleukin 2 (PEG-rhIL-2) obtained by site-specific conjugation of polyethylene glycol (PEG) with non-natural amino acids, and to explore its antitumor mechanism. METHODS: The binding activities of PEG-rhIL-2 at three different sites (T41, Y45, and V91) to human interleukin 2 receptors α (IL-2R_α) and β (IL-2R_β) and were detected by surface plasmon resonance (SPR) technology. Western blot was used to detect the levels of the Janus kinase-signal transducer and activator of transcription 5 (JAK-STAT5) signaling pathway activated by different doses of rhIL-2 and PEG-rhIL-2 in CTTL-2 and YT cells. Blood was collected after a single administration in mice to detect the drug concentration at different time points and evaluate the pharmacokinetic parameters of Y45-PEG-rhIL-2. Mouse hepatoma cell line Hepa1-6, pancreatic cancer cell line Pan-02, and colon cancer cell line MC-38 were selected. Tumor models were constructed in C57BL/6 mice. Different doses of Y45-PEG-rhIL-2 and excipient control were administrated respectively to evaluate the tumor suppression effect of the drug. In the MC-38 colon cancer model, the tumor suppression effect of Y45-PEG-rhIL-2 combined with anti-programmed death-1 (PD-1) monoclonal antibody was evaluated. Hepa1-6 mouse tumor models were constructed and rhIL-2, Y45-rhIL-2 and Y45-PEG-rhIL-2 were administrated respectively. The proportion of tumor-infiltrating lymphocytes was analyzed by flow cytometry. RESULTS: The SPR detection results showed that the binding activities of PEG-rhIL-2 to IL-2R_α/IL-2R_β were both reduced. The affinity of Y45-PEG-rhIL-2 to IL-2R_α was reduced to approximately 1/250, and its affinity to IL-2R_β was reduced to 1/3. Western blot results showed that the activity of Y45-PEG-rhIL-2 in stimulating JAK-STAT5 signaling in CTLL-2 cells expressing heterotrimeric IL-2 receptor complex IL-2R_αβγwas reduced to approximately 1/300, while its activity in YT cells expressing heterodimeric IL-2 receptor complex IL-2R_βγwas reduced to approximately 1/3. The pharmacokinetic evaluation after a single dose in the mice showed that the elimination half-life of Y45-PEG-rhIL-2 was 17.7 h. Y45-PEG-rhIL-2 has pharmacokinetic characteristics superior to those of rhIL-2. Y45-PEG-rhIL-2 showed dose-dependent tumor suppression activity, and the combination of Y45-PEG-rhIL-2 and anti-PD-1 antibody had a better tumor-inhibiting effect than the single use of Y45-PEG-rhIL-2 or anti-PD-1 antibody. Flow cytometry analysis demonstrated that 72 h after the administration of Y45-PEG-rhIL-2, the proportion of tumor-infiltrating cytotoxic T lymphocytes (CD8⁺T cells) increased by 86.84%. At 120 h after administration, the ratio of CD8⁺T cells to regulatory T cells (Treg) increased by 75.10%. CONCLUSION Y45-PEG-rhIL-2 obtained by site-specific conjugation via non-natural amino acids changed its receptor binding activity and inhibited tumor growth in dose-dependent manner in multiple tumor models by regulating CD8⁺T cells.
Interleukin-2/pharmacokinetics* ; Animals ; Mice ; Humans ; Recombinant Proteins/pharmacology* ; Polyethylene Glycols/chemistry* ; Cell Line, Tumor ; Antineoplastic Agents/pharmacokinetics* ; Signal Transduction/drug effects* ; STAT5 Transcription Factor/metabolism* ; Interleukin-2 Receptor alpha Subunit/metabolism* ; Interleukin-2 Receptor beta Subunit/metabolism*

OBJECTIVE: To observe the dynamic changes of microvascular injury and repair in the penumbra of traumatic brain injury (TBI) rats with effective cerebral perfusion microvascular imaging using optical coherence tomography angiography (OCTA). METHODS: Transparent closed cranial windows were placed in craniotomy rats after TBI caused by weight drop. All the rats in TBI group and control group underwent head MRI examination on the first postoperative day, and the changes of cerebral cortical microvessel density were measured by OCTA through cranial windows on d0, d2, d4, d6, and d8. On the second day after the operation, the same number of rats in the two groups were selected to complete the immunohistochemical staining of brain tissue with pimonidazole, an indicator of hypoxia. RESULTS: MRI T2W1 and immunohistochemical staining demonstrated that edema and hypoxia in the traumatic brain tissue extended deeply throughout the entire cortex. OCTA showed that the cortical surface veins of the rats in both groups were significantly dilated and tortuous after operation, and recovered to the postoperative day level on d8. The effective perfusion microvessel density of the rats in both groups gradually recovered after a temporary decrease, and the TBI group decreased from 39.38%±4.48% on d0 to 27.84%±6.01% on d2, which was significantly lower than that on d0, d6, and d8 (P < 0.05). The highest value was 61.71%±7.69% on d8, which was significantly higher than that on d0, d2, and d4 (P < 0.05). The control group decreased from 44.59%±7.78% on d0 to 36.69%±5.49% on d2, which was significantly lower than that on d0, d6, and d8 (P < 0.05). The highest value was 51.92%±5.96% on d8, which was significantly higher than that on d2, and d4 (P < 0.05). Comparing the two groups, the effective perfusion microvessel density in the TBI group was significantly lower than that in the control group on d2 (P=0.021), and significantly higher than that in the control group on d8 (P=0.030). CONCLUSION OCTA can be used as a method of imaging and measurement of effective perfusion microvessels in the injured cerebral cortex of TBI rats. After TBI, the effective perfusion microvessel density in the wound penumbra gradually recovered after decreasing, and increased significantly on d8.
Animals ; Brain Injuries, Traumatic/physiopathology* ; Rats ; Tomography, Optical Coherence/methods* ; Male ; Rats, Sprague-Dawley ; Microvessels/pathology* ; Microvascular Density ; Cerebral Cortex/blood supply* ; Cerebrovascular Circulation

OBJECTIVE: To study incident and clinical characteristics of the coronary microcirculation dysfunction (CMD) in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI) by myocardial contrast echocardiography (MCE) and to explore the predictive value of CMD for in-hospital acute heart failure event. METHODS: One hundred and forty five patients with AMI who had received PCI and completed MCE during hospitalization in Peking University People' s Hospital from November 2015 to July 2021 were enrolled in our study. The patients were divided into CMD group and normal group according to the coronary microcirculation status detected by MCE. Clinical data and MCE data of the two groups were collected and analyzed. The acute heart failure event during hospitalization was described. A multivariate Logistic regression model was built to analyze the risk of acute heart failure in patients with CMD. A receiver operating characteristic (ROC) curve was drawn to evaluate the value of CMD in predicting acute heart failure event. RESULTS: CMD detected by MCE occurred in 87 patients (60%). Compared with normal group, patients with CMD had higher troponin I (TnI) peak level [52.8 (8.1, 84.0) μg/L vs. 18.9 (5.7, 56.1) μg/L, P=0.005], poorer Killip grade on admission (P=0.030), different culprit vessel (P < 0.001) and more patients had thrombolysis in myocardial infarction (TIMI) flow pre-PCI less than grade 3 in culprit vessel (65.1% vs. 43.1%, P=0.025). Meanwhile, patients with CMD had poorer left ventricular ejection fraction (LVEF) [52% (43%, 58%) vs. 61% (54%, 66%)], poorer global longitudinal strain (GLS) [-11.2% (-8.7%, -14.0%) vs.-13.9% (-10.8%, -17.0%)] and worse wall motion score index (WMSI) (1.58±0.36 vs. 1.25± 0.24) (P all < 0.001). Acute left heart failure happened in 13.8% of the CMD patients, which were significant higher than that in the patients with normal coronary microcirculation perfusion (1.7%, P=0.013). After correcting for the culprit vessel, the TIMI flow pre-PCI in the culprit vessel and the peak TnI value, the risk of acute left heart failure in the patients with CMD was still high (OR=9.120, 95%CI: 1.152-72.192, P=0.036). The area under ROC curve (AUC) was 0.677 (95%CI: 0.551-0.804, P=0.035). CONCLUSION The incidence of CMD detected by MCE in patients with AMI post-PCI was 60%. Patients with CMD have a higher risk of acute left heart failure during hospitalization.
Humans ; Heart Failure/physiopathology* ; Microcirculation ; Percutaneous Coronary Intervention/adverse effects* ; Myocardial Infarction/complications* ; Male ; Female ; Hospitalization ; Middle Aged ; Aged ; Echocardiography ; Coronary Circulation ; Predictive Value of Tests ; Troponin I/blood*

OBJECTIVE: To investigate the effect of intraoperative blood salvage autotransfusion on local recurrence and long-term metastasis of patients after carotid body tumor resection. METHODS: We retrospectively reviewed a consecutive series of 61 patients undergoing elective carotid body tumor resection from August 2009 to December 2020. Among them, 14 received intraoperative blood salvage autotransfusion (autotrasfusion group) and 47 did not (non-autotransfusion). Data of general information, surgical status and postoperative follow-up results were collected. RESULTS: The proportion of Shamblin Ⅲ in the autotransfusion group was 85.7%, which was significantly higher than 31.9% in the non-autotransfusion group (P=0.003). The average operation time of the 14 patients in the autotransfusion group was (264±84) min, intraoperative blood loss was 1 200 (700, 2 700) mL, and autologous blood transfusion was 500 (250, 700) mL. Of these, 8 patients (57%) required concomitant allogeneic blood with 400 (260, 400) mL of allogeneic blood. The average operation time of the 47 patients in the non-autotransfusion group was (153±75) min, and the intraoperative blood loss was 300 (100, 400) mL. Of these, 6 (13%) required allogeneic blood transfusion, and 520 (400, 520) mL of allogeneic blood was used. Compared with the non-autotransfusion group, the average operation time in the autologous blood transfusion group was significantly longer (P < 0.001), and the intraoperative blood transfusion volume was larger (P=0.007). Of the 14 patients undergoing autotransfusion, 8 (57%) needed allogeneic blood at the same time; while in the 47 non-autologous transfusion patients, 6 (13%) needed allogeneic blood transfusion. The proportion of autotransfusion group using allogeneic blood at the same time was even higher (P=0.002). The incidence of nerve injury within 30 days after surgery was 29.5%, and there was no significant difference between the two groups. No early deaths occurred. The average follow-up was (76±37) months. One case of local recurrence occurred in the non-autotransfusion group. There was no distant metastasis. There were no tumor-related deaths. The estimated 5-year and 10-year overall survival rates were 96.4% and 83.8%, respectively. There was no significant difference in overall survival between the two groups (P=0.506). CONCLUSION The use of intraoperative blood salvage autotransfusion increased no risk of local recurrence and distant metastasis in patients with carotid body tumor, which is safe and effective in carotid body tumor resection.
Humans ; Blood Transfusion, Autologous/methods* ; Operative Blood Salvage/methods* ; Retrospective Studies ; Male ; Female ; Carotid Body Tumor/pathology* ; Middle Aged ; Prognosis ; Neoplasm Recurrence, Local ; Blood Loss, Surgical ; Aged ; Adult ; Operative Time

OBJECTIVE: To compare the differences of plasma valine level between autistic and healthy children, and to explore the relationship between plasma valine level and developmental quotient in children with autism. METHODS: In this study, a total of 29 autistic children and 30 typically developing children of the same age range were recruited as the autistic group and the control group. The childhood autism rating scale (CARS) was used to assess autistic core symptoms and severity in the autistic children. Children's developmental quotient was evaluated by Gesell developmental schedules (GDS), and plasma valine level was measured by high performance liquid chromatography-tandem mass spectrometry. The correlation between plasma valine level and developmental quotient scores in the autistic group was analyzed. RESULTS: The plasma level of valine in the autism group was significantly lower than in the control group (P < 0.05). Children in the autism group got significantly lower scores in the adaption, gross motor, fine motor, language function and personal/social function subscales in GDS than in the control group (P < 0.000 1). Plasma valine level in the autism group showed significant positive correlations with scores of the fine motor (r=0.441, P < 0.05) and personal/social function (r=0.437, P < 0.05) subscales in GDS, but showed no significant correlations with scores of the adaption, gross motor and language function subscales in GDS (P>0.05). According to the criteria of CARS, children in the autism group were subdivided into the mild to moderate subgroup and the severe subgroup based on the severity of the autistic symptoms. Compared with children in the mild to moderate subgroup, children in the severe subgroup got significantly lower scores in the adaption, fine motor, language function and personal/social function subscales in GDS (P < 0.05), while there was no significant difference between the two subgroups in gross motor scores and plasma valine level (P>0.05). CONCLUSION The level of valine in plasma of autistic children is relatively lower, and there is a certain relationship between plasma valine level and the fine movement and personal/social function among children with autism.
Humans ; Autistic Disorder/physiopathology* ; Child ; Male ; Female ; Valine/blood* ; Child Development ; Child, Preschool ; Case-Control Studies

OBJECTIVE: To explore whether streptococcal infection may aggravate renal damage in children with Henoch-Schönlein purpura nephritis and its possible mechanism. METHODS: In the study, 485 children diagnosed with Henoch-Schönlein purpura nephritis from July 2015 to December 2019 were selected to analyze their clinical data retrospectively. According to the diagnosis of discharge, whether it was combined with streptococcal infection, the children were divided into two groups. The experimental group contained 91 children with Henoch-Schönlein purpura nephritis combined with streptococcal infection, and there were 394 children who were not infected with Streptococcus in the control group. Suitable test items were preliminarily selected through artificial neural network, and then data analysis was performed through SPSS 23.0. RESULTS: The children with Henoch-Schönlein purpura nephritis infected with streptococcus had statistically significant differences compared with the uninfected children in the test items of urine protein, liver and kidney function, immunoglobulin and complement. Anti-streptolysin O had mild correlation with IgG (Spearman r=-0.328), fibrin degradation products (Spearman r=-0.207), total protein (Spearman r=-0.202) and globulin (Spearman r=-0.223). Compared with the children who were not infected with streptococcus, the differences of the average levels of age (P=0.001), IgG (P < 0.001), fibrin degradation products (P=0.019), total protein (P < 0.001), globulin (P < 0.001), IgA (P < 0.001), IgM (P=0.003), complement 3 (P=0.016), complement 4 (P=0.002), albumin/globulin ratio (P=0.007), alkaline phosphatase (P=0.036), and estimated glomerular filtration rate (P=0.039) in the infected children were statistically significant. In order to explore the risk factors of kidney damage in the children with Henoch-Schönlein purpura nephritis, Logistic regression was performed using anti-streptolysin O, age, immunoglobulin and complement as independent variables, urine protein detection parameters, liver and kidney functions as dependent variables. Age ≤10 years old and hypocomplementemia might be risk factors for aggravating renal damage in the children with Henoch-Schönlein purpura nephritis. CONCLUSION Streptococcal infections may aggravate renal damage in children with Henoch-Schönlein purpura nephritis, in which hypocomplementemia, inflammation, fibrinolysis and disorders of coagulation perhaps play an important role. Children with streptococcal infection should be treated with anti-infective treatment in time and necessarily, and followed up after discharge regularly.
Humans ; IgA Vasculitis/complications* ; Streptococcal Infections/complications* ; Child ; Male ; Female ; Nephritis/microbiology* ; Retrospective Studies ; Child, Preschool ; Kidney/pathology* ; Adolescent