ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Objective To explore the construction of α-1,3-galactosyltransferase (GGTA1) gene-knockout (GTKO) Diannan miniature pigs and the kidney xenotransplantation from pigs to rhesus macaques, and to assess the effectiveness of GTKO pigs. Methods The GTKO Diannan miniature pigs were constructed using the CRISPR/Cas9 gene-editing system and somatic cell cloning technology. The phenotype of GTKO pigs was verified through polymerase chain reaction, Sanger sequencing and immunofluorescence staining. Flow cytometry was used to detect antigen-antibody (IgM) binding and complement-dependent cytotoxicity. Kidney xenotransplantation was performed from GTKO pigs to rhesus macaques. The humoral immunity, cellular immunity, coagulation and physiological indicators of the recipient monkeys were monitored. The function and pathological changes of the transplanted kidneys were analyzed using ultrasonography, hematoxylin-eosin staining, immunohistochemical staining and immunofluorescence staining. Results Single-guide RNA (sgRNA) targeting exon 4 of the GGTA1 gene in Diannan miniature pigs was designed. The pGL3-GGTA1-sgRNA1-GFP vector was transfected into fetal fibroblasts of Diannan miniature pigs. After puromycin selection, two cell clones, C59# and C89#, were identified as GGTA1 gene-knockout clones. These clones were expanded to form cell lines, which were used as donor cells for somatic cell nuclear transfer. The reconstructed embryos were transferred into the oviducts of trihybrid surrogate sows, resulting in 13 fetal pigs. Among them, fetuses F04 and F11 exhibited biallelic mutations in the GGTA1 gene, and F04 had a normal karyotype. Using this GTKO fetal pig for recloning and transferring the reconstructed embryos into the oviducts of trihybrid surrogate sows, seven surviving piglets were obtained, all of which did not express α-Gal epitope. The binding of IgM from the serum of rhesus monkey 20# to GTKO pig PBMC was reduced, and the survival rate of GTKO pig PBMC in the complement-dependent cytotoxicity assay was higher than that of wild-type pig. GTKO pig kidneys were harvested and perfused until completely white. After the left kidney of the recipient monkey was removed, the pig kidney was heterotopically transplanted. Following vascular anastomosis and blood flow restoration, the pig kidney rapidly turned pink without hyperacute rejection (HAR). Urine appeared in the ureter 6 minutes later, indicating successful kidney transplantation. The right kidney of the recipient was then removed. Seven days after transplantation, the transplanted kidney had good blood flow, the recipient monkey's serum creatinine level was stable, and serum potassium and cystatin C levels were effectively controlled, although they increased 10 days after transplantation. Seven days after transplantation, the levels of white blood cells, lymphocytes, monocytes and eosinophils in the recipient monkey increased, while platelet count and fibrinogen levels decreased. The activated partial thromboplastin time, thrombin time and prothrombin time remained relatively stable but later showed an upward trend. The recipient monkey survived for 10 days. At autopsy, the transplanted kidney was found to be congested, swollen and necrotic, with a small amount of IgG deposition in the renal tissue, and a large amount of IgM, complement C3c and C4d deposition, as well as CD68⁺ macrophage infiltration. Conclusions The kidneys of GTKO Diannan miniature pigs may maintain normal renal function for a certain period in rhesus macaques and effectively overcome HAR, confirming the effectiveness of GTKO pigs for xenotransplantation.

From the perspective of competitive endogenous RNA(ceRNA) constructed by metastasy-associated lung adenocarcinoma transcript 1(Malat1) and microRNA 16-5p(miR-16-5p), the improvement mechanism of Tonggu Xiaotong Capsules(TGXTC) on the imbalance and disorder of "cholesterol-iron" metabolism in chondrocytes of osteoarthritis(OA) was explored. In vivo experiments, 60 8-week-old C57BL/6 mice were acclimatized and fed for 1 week and then randomly divided into two groups: blank group(12 mice) and modeling group(48 mice). The animals in modeling group were anesthetized by 5% isoflurane inhalation, which was followed by the construction of OA model. They were then randomly divided into model group, TGXTC group, Malat1 overexpression group, and TGXTC+Malat1 overexpression(TGXTC+Malat1-OE) group, with 12 mice in each group. The structural changes of mouse cartilage tissues were observed by Masson staining after the intervention in each group. RT-PCR was employed to detect the mRNA levels of Malat1 and miR-16-5p in cartilage tissues. Western blot was used to analyze the protein expression of ATP-binding cassette transporter A1(ABCA1), sterol regulatory element-binding protein(SREBP), cytochrome P450 family 7 subfamily B member 1(CYP7B1), CCAAT/enhancer-binding protein homologous protein(CHOP), acyl-CoA synthetase long-chain family member 4(ACSL4), and glutathione peroxidase 4(GPX4) in cartilage tissues. In vitro experiments, mouse chondrocytes were induced by thapsigargin(TG), and the combination of Malat1 and miR-16-5p was detected by double luciferase assay. The fluorescence intensity of Malat1 in chondrocytes was determined by fluorescence in situ hybridization. The miR-16-5p inhibitory chondrocyte model was constructed. RT-PCR was used to analyze the levels of Malat1 and miR-16-5p in chondrocytes under the inhibition of miR-16-5p. Western blot was adopted to analyze the regulation of TG-induced chondrocyte proteins ABCA1, SREBP, CYP7B1, CHOP, ACSL4, and GPX4 by TGXTC under the inhibition of miR-16-5p. The results of in vivo experiments showed that,(1) compared with model group, TGXTC group exhibited a relatively complete cartilage layer structure. Compared with Malat1-OE group, TGXTC+Malat1-OE group showed alleviated cartilage surface damage.(2) Compared with model group, TGXTC group had a significantly decreased Malat1 mRNA level and an increased miR-16-5p mRNA level in mouse cartilage tissues(P<0.01).(3) Compared with the model group, the protein levels of ABCA1 and GPX4 in the cartilage tissue of mice in the TGXTC group increased, while the protein levels of SREBP, CYP7B1, CHOP and ACSL4 decreased(P<0.01). The results of in vitro experiments show that,(1) dual-luciferase was used to evaluate that miR-16-5p has a targeting effect on the Malat1 gene.(2)Compared with TG+miR-16-5p inhibition group, TG+miR-16-5p inhibition+TGXTC group had an increased mRNA level of miR-16-5p and an decreased mRNA level of Malat1(P<0.01).(3) Compared with TG+miR-16-5p inhibition group, TG+miR-16-5p inhibition+TGXTC group exhibited increased expression of ABCA1 and GPX4 proteins and decreased expression of SREBP, CYP7B1, CHOP, and ACSL4 proteins(P<0.01). The reasults showed that TGXTC can regulate the ceRNA of Malat1 and miR-16-5p to alleviate the "cholesterol-iron" metabolism disorder of osteoarthritis chondrocytes.
Animals ; MicroRNAs/metabolism* ; RNA, Long Noncoding/metabolism* ; Chondrocytes/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Mice, Inbred C57BL ; Mice ; Osteoarthritis/drug therapy* ; Iron/metabolism* ; Male ; Cholesterol/metabolism* ; Humans ; Capsules ; RNA, Competitive Endogenous

OBJECTIVE: To assess the efficacy of Qingda Granule (QDG) in ameliorating hypertension-induced cardiac damage and investigate the underlying mechanisms involved. METHODS: Twenty spontaneously hypertensive rats (SHRs) were used to develope a hypertension-induced cardiac damage model. Another 10 Wistar Kyoto (WKY) rats were used as normotension group. Rats were administrated intragastrically QDG [0.9 g/(kg•d)] or an equivalent volume of pure water for 8 weeks. Blood pressure, histopathological changes, cardiac function, levels of oxidative stress and inflammatory response markers were measured. Furthermore, to gain insights into the potential mechanisms underlying the protective effects of QDG against hypertension-induced cardiac injury, a network pharmacology study was conducted. Predicted results were validated by Western blot, radioimmunoassay immunohistochemistry and quantitative polymerase chain reaction, respectively. RESULTS: The administration of QDG resulted in a significant decrease in blood pressure levels in SHRs (P<0.01). Histological examinations, including hematoxylin-eosin staining and Masson trichrome staining revealed that QDG effectively attenuated hypertension-induced cardiac damage. Furthermore, echocardiography demonstrated that QDG improved hypertension-associated cardiac dysfunction. Enzyme-linked immunosorbent assay and colorimetric method indicated that QDG significantly reduced oxidative stress and inflammatory response levels in both myocardial tissue and serum (P<0.01). CONCLUSIONS Both network pharmacology and experimental investigations confirmed that QDG exerted its beneficial effects in decreasing hypertension-induced cardiac damage by regulating the angiotensin converting enzyme (ACE)/angiotensin II (Ang II)/Ang II receptor type 1 axis and ACE/Ang II/Ang II receptor type 2 axis.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Hypertension/pathology* ; Renin-Angiotensin System/drug effects* ; Rats, Inbred SHR ; Oxidative Stress/drug effects* ; Male ; Rats, Inbred WKY ; Blood Pressure/drug effects* ; Myocardium/pathology* ; Rats ; Inflammation/pathology*

OBJECTIVE: To evaluate the efficacy and safety of Shexiang Tongxin Dropping Pill (STDP) in treating stable angina patients with phlegm-heat and blood-stasis syndrome by exercise duration and metabolic equivalents. METHODS: This multicenter, randomized, double-blind, placebo-controlled clinical trial enrolled stable angina patients with phlegm-heat and blood-stasis syndrome from 22 hospitals. They were randomized 1:1 to STDP (35 mg/pill, 6 pills per day) or placebo for 56 days. The primary outcome was the exercise duration and metabolic equivalents (METs) assessed by the standard Bruce exercise treadmill test after 56 days of treatment. The secondary outcomes included the total angina symptom score, Chinese medicine (CM) symptom scores, Seattle Angina Questionnaire (SAQ) scores, changes in ST-T on electrocardiogram and adverse events (AEs). RESULTS: This trial enrolled 309 patients, including 155 and 154 in the STDP and placebo groups, respectively. STDP significantly prolonged exercise duration with an increase of 51.0 s, compared to a decrease of 12.0 s with placebo (change rate: -11.1% vs. 3.2%, P<0.01). The increase in METs was significantly greater in the STDP group than in the placebo group (change: -0.4 vs. 0.0, change rate: -5.0% vs. 0.0%, P<0.01). The improvement of total angina symptom scores (25.0% vs. 0.0%), CM symptom scores (38.7% vs. 11.8%), reduction of nitroglycerin consumption (100.0% vs. 11.3%), and all domains of SAQ, were significantly greater with STDP than placebo (all P<0.01). The changes in Q-T intervals at 28 and 56 days from baseline were similar between the two groups (both P>0.05). Twenty-five participants (16.3%) with STDP and 16 (10.5%) with placebo experienced AEs (P=0.131), with no serious AEs observed. CONCLUSION STDP could improve exercise tolerance in patients with stable angina and phlegm-heat and blood stasis syndrome, with a favorable safety profile. (Registration No. ChiCTR-IPR-15006020).
Humans ; Double-Blind Method ; Drugs, Chinese Herbal/adverse effects* ; Male ; Female ; Middle Aged ; Angina, Stable/physiopathology* ; Aged ; Syndrome ; Treatment Outcome ; Placebos ; Tablets

OBJECTIVES: To investigate the effects of periodontitis induced by Prevotella nigrescens (Pn) combined with ligation on cognitive functions in mice. METHODS: Twenty-four C57BL/6J mice were randomly divided into control group, ligation group, and ligation + Pn treatment (P+Pn) group. Experimental periodontitis was induced by silk ligation of the first molars followed by topical application of Pn for 6 weeks. After modeling, alveolar bone resorption was assessed using micro-CT and histological analysis. Learning and memory abilities of the mice were evaluated using open field test (OFT), novel object recognition test (NORT), and Morris water maze test (MWM). Seven weeks after the start of modeling, the mice were sacrificed for examining histopathological changes in the hippocampus using HE and Nissl staining. RESULTS: After 6 weeks of molar ligation, micro-CT revealed horizontal alveolar bone resorption and furcation exposure in the mice, and histological analysis showed apical migration of the junctional epithelium, epithelial ridge hyperplasia, and lymphocyte infiltration, and these changes were obviously worsened in P+Pn group. Alveolar bone height decreased significantly in both ligation groups compared to the control group. Cognitive tests showed that the mice in both of the ligation groups traveled shorter distances in OFT, showed reduced novel object preference in NORT, and exhibited longer escape latencies in MWM, and the mice in P+Pn group had significantly poorer performances in the tests. Histologically, obvious neuronal cytoplasmic degeneration, necrosis, nuclear pyknosis, vacuolation, and reduced Nissl bodies and viable neurons were observed in the hippocampal regions of the mice in the two ligation groups. CONCLUSIONS Pn infection aggravates alveolar bone destruction, accelerates necrosis and causes morphological abnormalities of neuronal cells in the hippocampus to reduce cognitive functions of mice with periodontitis.
Animals ; Periodontitis/microbiology* ; Mice ; Mice, Inbred C57BL ; Cognition ; Alveolar Bone Loss ; Hippocampus/pathology* ; Male ; Inflammation ; Maze Learning

OBJECTIVE: This study aimed to investigate the prevalence of HIV pretreatment drug resistance (PDR) and the transmission clusters associated with PDR-related mutations in newly diagnosed, treatment-naive patients between 2020 and 2023 in Dehong prefecture, Yunnan province, China. METHODS: Demographic information and plasma samples were collected from study participants. PDR was assessed using the Stanford HIV Drug Resistance Database. The Tamura-Nei 93 model within HIV-TRACE was employed to compute pairwise matches with a genetic distance of 0.015 substitutions per site. RESULTS: Among 948 treatment-naive individuals with eligible sequences, 36 HIV subtypes were identified, with unique recombinant forms (URFs) being the most prevalent (18.8%, 178/948). The overall prevalence of PDR was 12.4% (118/948), and resistance to non-nucleotide reverse transcriptase inhibitors (NNRTIs), nucleotide reverse transcriptase inhibitors (NRTIs), and protease inhibitors (PIs) was 10.7%, 1.3%, and 1.6%, respectively. A total of 91 clusters were identified, among which eight showed evidence of PDR strain transmission. The largest PDR-associated cluster consisted of six CRF01_AE drug-resistant strains carrying K103N and V179T mutations; five of these individuals had initial CD4+ cell counts < 200 cells/μL. CONCLUSION The distribution of HIV subtypes in Dehong is diverse and complex. PDR was moderately prevalent (12.4%) between 2020 and 2023. Evidence of transmission of CRF01_AE strains carrying K103N and V179T mutations was found. Routine surveillance of PDR and the strengthening of control measures are essential to limit the spread of drug-resistance HIV strains.
Humans ; HIV Infections/virology* ; China/epidemiology* ; Drug Resistance, Viral ; Male ; Adult ; Female ; Middle Aged ; HIV-1/genetics* ; Anti-HIV Agents/therapeutic use* ; Myanmar/epidemiology* ; Young Adult ; Prevalence ; Adolescent ; Mutation

Objective To investigate the formation and mechanism of dipeptidylpeptidase-4 inhibitor anagliptin inhibiting lung metastasis of colorectal cancer.Methods Twenty-four male BALB/c mice were randomly divided into normal group,model group,anagliptin group.The control group did not undergo any treatment.The model group was injected with 0.1 ml CT-26 cells of 109 cells/L.once through the tail vein of the mouse to construct a lung metastasis model,while the anagliptin group was injected intraperitoneally 20 mg/(kg d)0 day after constructing a lung metastasis model.The mice were sacrificed after 14 days.HE staining was used to detect the morphological alteration.Determination of CT-26 cell viability through MTT assay and CT-26 cell apoptosis was detected by flow cytometry and live/dead cell staining.Reactive oxygen species(ROS)production was measured by ROS kit.Western blotting was conducted to measure the expression level of Bcl-2,Bax,cleaved-caspase-3,superoxide dismutase(SOD-1)and SOD-2.Results HE staining showed that the administration of anagliptin could significantly inhibit the abnormal changes in the model group.Anagliptin inhibited the viability of CT-26 cells above 2 mmol/L.Anagliptin promoted the apoptosis of CT-26 cells.Incubation of anagliptin in CT-26 cells significant promoted the production of ROS.Incubation of anagliptin stimulated the expressions of Bax and cleaved-Caspase-3,while down-regulated the expression of Bcl-2 in CT-26 cells.Administration of anagliptin decreased the expression of SOD-1,but not SOD-2.Conclusion Anagliptin promotes apoptosis of colorectal cancer cells and inhibits the formation of lung metastatic tumors through the SOD-1/ROS pathway.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.