BACKGROUND:The plateau environment affects the immune function and metabolic status of patients with osteomyelitis,leading to acceleration or complication of the disease process.The construction of effective and stable animal models of chronic osteomyelitis is essential for experimental studies of chronic osteomyelitis.OBJECTIVE:To establish a sheep model of chronic osteomyelitis in plateau regions for toxicity assessment and therapeutic research.METHODS:Fifteen healthy sheep were selected in this study.Sodium morrhuate and Staphylococcus aureus suspension were injected into the medullary cavity of the middle segment of the tibia to establish the chronic osteomyelitis model.General observation,body mass and temperature monitoring,blood infection index detection,radiological scoring,and microbial culture were performed for evaluation and analysis.RESULTS AND CONCLUSION:(1)Local tissue swelling and lameness of the affected leg were observed in all sheep in the early stage after modeling,accompanied by varying degrees of anorexia.A slight decrease in body mass was observed in sheep 1 week after modeling,while no significant changes in body temperature were observed.(2)The erythrocyte sedimentation rate significantly accelerated 4 days after modeling(P<0.05)and gradually returned to normal levels after 1 month.The white blood cell count showed a significant increase within 4 days after modeling and returned to normal after 1 week.The level of C-reactive protein increased significantly after modeling(P<0.05)and remained significantly higher than normal until the end of the experiment(P<0.05).(3)Fifteen sheep exhibited typical radiological manifestations of osteomyelitis,including unclear boundaries,irregular osteolytic lesions,and low-density bright absorption areas with interspersed necrotic bone fragments of increased and uneven density.Different degrees of periosteal reaction were observed in the cortex near the lesion.(4)Thirteen sheep were cultured for a single strain of Staphylococcus aureus,while two sheep were cultured for Staphylococcus aureus and Escherichia coli.These findings indicate that a reliable chronic osteomyelitis animal model of sheep tibia can be successfully established in plateau regions by injecting an appropriate amount of Staphylococcus aureus suspension into the medullary cavity of sheep,combined with local implantation of foreign cotton thread and sodium morrhuate.

BACKGROUND: The primary limitation to kidney transplantation is organ shortage. Recent progress in gene editing and immunosuppressive regimens has made xenotransplantation with porcine organs a possibility. However, evidence in pig-to-human xenotransplantation remains scarce, and antibody-mediated rejection (AMR) is a major obstacle to clinical applications of xenotransplantation. METHODS: We conducted a kidney xenotransplantation in a brain-dead human recipient using a porcine kidney with five gene edits (5GE) on March 25, 2024 at Xijing Hospital, China. Clinical-grade immunosuppressive regimens were employed, and the observation period lasted 22 days. We collected and analyzed the xenograft function, ultrasound findings, sequential protocol biopsies, and immune surveillance of the recipient during the observation. RESULTS: The combination of 5GE in the porcine kidney and clinical-grade immunosuppressive regimens prevented hyperacute rejection. The xenograft kidney underwent delayed graft function in the first week, but urine output increased later and the single xenograft kidney maintained electrolyte and pH homeostasis from postoperative day (POD) 12 to 19. We observed AMR at 24 h post-transplantation, due to the presence of pre-existing anti-porcine antibodies and cytotoxicity before transplantation; this AMR persisted throughout the observation period. Plasma exchange and intravenous immunoglobulin treatment mitigated the AMR. We observed activation of latent porcine cytomegalovirus toward the end of the study, which might have contributed to coagulation disorder in the recipient. CONCLUSIONS 5GE and clinical-grade immunosuppressive regimens were sufficient to prevent hyperacute rejection during pig-to-human kidney xenotransplantation. Pre-existing anti-porcine antibodies predisposed the xenograft to AMR. Plasma exchange and intravenous immunoglobulin were safe and effective in the treatment of AMR after kidney xenotransplantation.
Transplantation, Heterologous/methods* ; Kidney Transplantation/methods* ; Heterografts/pathology* ; Immunoglobulins, Intravenous/administration & dosage* ; Graft Survival/immunology* ; Humans ; Animals ; Sus scrofa ; Graft Rejection/prevention & control* ; Kidney/pathology* ; Gene Editing ; Species Specificity ; Immunosuppression Therapy/methods* ; Plasma Exchange ; Brain Death ; Biopsy ; Male ; Aged

Ulcerative colitis (UC) is a chronic inflammatory disorder with a complex etiology, characterized by intestinal inflammation and barrier dysfunction. Platycodon grandiflorus polysaccharides (PGP), the primary component of Platycodon grandiflorus, and hesperidin (Hesp), a prominent active component in Citrus aurantium L. (CAL), have both demonstrated anti-inflammatory properties. This study aims to elucidate the underlying mechanism of the synergistic effect of PGP combined with Hesp on UC, focusing on the coordinated interaction between the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathways. A mouse model of UC induced by dextran sulfate sodium (DSS) and a cell model using lipopolysaccharide (LPS)-induced RAW264.7/IEC6 cells were employed to investigate the in vitro and in vivo anti-inflammatory effects of PGP combined with Hesp on UC and its potential mechanism of action. The results indicated that compared to the effects of either drug alone, the combination of PGP and Hesp significantly modulated inflammatory factor levels, inhibited oxidative stress, regulated colonic mucosal immunity, suppressed apoptosis, and restored intestinal barrier function in vitro and in vivo. Further in vitro studies revealed that PGP significantly inhibited the PI3K/AKT signaling pathway, while Hesp significantly inhibited the JAK2/STAT3 signaling pathway. The use of inhibitors and activators targeting both pathways validated the synergistic effects of PGP combined with Hesp on the PI3K/AKT and JAK2/STAT3 signaling pathways. These findings suggest that PGP combined with Hesp exhibits a synergistic effect on DSS-induced colitis, potentially mediated through the phosphatase and tensin homolog (PTEN)/PI3K/AKT and interleukin-6 (IL-6)/JAK2/STAT3 signaling pathways.
Animals ; STAT3 Transcription Factor/genetics* ; Janus Kinase 2/genetics* ; Polysaccharides/administration & dosage* ; Colitis, Ulcerative/chemically induced* ; Mice ; Signal Transduction/drug effects* ; Proto-Oncogene Proteins c-akt/genetics* ; Drug Synergism ; Male ; Hesperidin/administration & dosage* ; Platycodon/chemistry* ; Phosphatidylinositol 3-Kinases/genetics* ; Disease Models, Animal ; RAW 264.7 Cells ; Mice, Inbred C57BL

Objective To evaluate the efficacy of a combined immunosuppression regimen in modulating rejection in genetically modified pig-to-macaque xenogeneic heart transplantation.Methods Two xenogeneic heart transplantation models were constructed using genetically modified pigs and macaques.Dynamic monitoring of recipient peripheral blood immune parameters and observation of graft pathological changes were performed.Results Regimen 1,featuring B-cell depletion,T-cell inhibition,and C3 complement suppression,reduced lymphocyte levels but failed to control acute humoral rejection and macrophage infiltration.Regimen 2,adding C5 complement inhibition and interleukin-6 inhibition to Regimen 1,more effectively lowered lymphocyte levels,inhibited acute humoral rejection and complement activation,and decreased antibody deposition.However,a late-phase cytokine storm and residual T cells emerged.Conclusions Regimen 2 reduces the hyperacute and acute rejection risks through multi-target intervention.Yet,it requires balancing medication complexity and safety.This indicates the need to optimize cellular immune regulation and adjust the plan through dynamic multidimensional monitoring.

Objective To evaluate the efficacy of a combined immunosuppression regimen in modulating rejection in genetically modified pig-to-macaque xenogeneic heart transplantation.Methods Two xenogeneic heart transplantation models were constructed using genetically modified pigs and macaques.Dynamic monitoring of recipient peripheral blood immune parameters and observation of graft pathological changes were performed.Results Regimen 1,featuring B-cell depletion,T-cell inhibition,and C3 complement suppression,reduced lymphocyte levels but failed to control acute humoral rejection and macrophage infiltration.Regimen 2,adding C5 complement inhibition and interleukin-6 inhibition to Regimen 1,more effectively lowered lymphocyte levels,inhibited acute humoral rejection and complement activation,and decreased antibody deposition.However,a late-phase cytokine storm and residual T cells emerged.Conclusions Regimen 2 reduces the hyperacute and acute rejection risks through multi-target intervention.Yet,it requires balancing medication complexity and safety.This indicates the need to optimize cellular immune regulation and adjust the plan through dynamic multidimensional monitoring.

BACKGROUND:The plateau environment affects the immune function and metabolic status of patients with osteomyelitis,leading to acceleration or complication of the disease process.The construction of effective and stable animal models of chronic osteomyelitis is essential for experimental studies of chronic osteomyelitis.OBJECTIVE:To establish a sheep model of chronic osteomyelitis in plateau regions for toxicity assessment and therapeutic research.METHODS:Fifteen healthy sheep were selected in this study.Sodium morrhuate and Staphylococcus aureus suspension were injected into the medullary cavity of the middle segment of the tibia to establish the chronic osteomyelitis model.General observation,body mass and temperature monitoring,blood infection index detection,radiological scoring,and microbial culture were performed for evaluation and analysis.RESULTS AND CONCLUSION:(1)Local tissue swelling and lameness of the affected leg were observed in all sheep in the early stage after modeling,accompanied by varying degrees of anorexia.A slight decrease in body mass was observed in sheep 1 week after modeling,while no significant changes in body temperature were observed.(2)The erythrocyte sedimentation rate significantly accelerated 4 days after modeling(P<0.05)and gradually returned to normal levels after 1 month.The white blood cell count showed a significant increase within 4 days after modeling and returned to normal after 1 week.The level of C-reactive protein increased significantly after modeling(P<0.05)and remained significantly higher than normal until the end of the experiment(P<0.05).(3)Fifteen sheep exhibited typical radiological manifestations of osteomyelitis,including unclear boundaries,irregular osteolytic lesions,and low-density bright absorption areas with interspersed necrotic bone fragments of increased and uneven density.Different degrees of periosteal reaction were observed in the cortex near the lesion.(4)Thirteen sheep were cultured for a single strain of Staphylococcus aureus,while two sheep were cultured for Staphylococcus aureus and Escherichia coli.These findings indicate that a reliable chronic osteomyelitis animal model of sheep tibia can be successfully established in plateau regions by injecting an appropriate amount of Staphylococcus aureus suspension into the medullary cavity of sheep,combined with local implantation of foreign cotton thread and sodium morrhuate.

Objective:To investigate the changing trends in cardiac function following xenogeneic heterotopic heart transplantation of multi-gene edited pig hearts and assess the impact of recipient immune responses on donor heart, laying experimental groundwork for the clinical application of gene editing technology.Methods:On December 16, 2023, xenogeneic heterotopic heart transplantation was performed between pigs and rhesus monkeys. Functional status of the graft under post-transplantation load conditions and recipient immune indicators were observed.Results:The recipient monkeys survived for 40 days with satisfactory functionality of both donor and recipient hearts, and no hyperacute or acute immune rejection reactions were observed.Conclusion:Multi-gene editing technology provides potential for xenotransplantation, yet further exploration is needed for its clinical application.

Objective:To study the effects of cathepsin K(CTSK)on the healing process of tooth extraction socket and type H blood vessel angiogenesis in mice.Methods:Ctsk knockout(Ctsk-/-)mice were generated by CRISPR/Cas9 technology,and genotype sequen-cing,general observation,Micro-CT and immunohistochemistry were performed to confirm successful knockout of Ctsk.Then 8 week-old WT and Ctsk-/-mice were used to establish the tooth extraction modle by extracting the left maxillary first molars,and the mice were sac-rificed at the day 7,10,14,21,28 and 35 respectively(n=3)after tooth extraction.Then samples were subjected to stereo microscope and Micro-CT examination.Immunofluorescence staining was used to study the effect of Ctsk knockout on type H blood vessel angiogene-sis.Results:Ctsk knockout did not affect the soft tissue healing of tooth extraction socket,but significantly promoted the bone healing process,and Ctsk deficency significantly enhanced type H blood vessel angiogenesis in the tooth extraction socket.Conclusion:Ctsk knockout can enhance type H vessel angiogenesis,and promote bone healing process of tooth extraction socket in mice.

Objective To investigate the clinical and cytogenetic characteristics of acute myeloid leukemia(AML)patients with NRAS mutations.Methods Newly diagnosed AML patients in our hospital from January 2020 to August 2022 were selected,and their clinical data were retrospectively analyzed.According to NRAS mutations,the patients were divided into NRAS mutation group and NRAS wild group.The clinical characteristics and cytogenetic differences were compared between the two groups.Results A total of 162 newly diagnosed AML patients were included in this study.There were 28 in NRAS mutation group and 134 in NRAS wild group.The peripheral white blood cell count of NRAS mutation group was significantly higher than that of NRAS wild type group(53.10×109/L vs 24.78×109/L,P<0.05).There were no significant differences in the hemoglobin level,platelet count or bone marrow blast cell count between the two groups(P>0.05).The coexisting gene mutation occurred in 25 patients(89.3%,25/28)in NRAS mutation group.The most common coexisting gene mutation was KRAS,with a mutation rate of 28.6%.Compared with NRAS wild group,NRAS mutation group was more likely to obtain KRAS mutations(P<0.05).There was no significant difference in other coexisting mutated genes between the two groups(P>0.05).The proportion of poor prognosis karyotype in the NRAS mutation group was 23.1%,which was significantly higher than that in NRAS wild group(P<0.05).The proportions of favorable and intermediate prognosis karyotypes in NRAS mutation group were 7.7%and 69.2%,respectively,which were not significantly different from those in NRAS wild group(P>0.05).Conclusion The incidence of NRAS mutation is 17.3%in AML patients in this study.Patients with NRAS mutation are more likely to have KRAS mutation and have a higher proportion of poor prognosis karyotype.

Objective To validate whether the expression of human cluster of differentiation 55 (hCD55) protein in porcine islet cells could inhibit the activation of complement components in human serum. Methods Four adult pigs with WT (wild type), GTKO [α-1, 3-galactosyltransferase (GGTA1) knockout], GTKO/hCD55 and hCD55 genotypes were selected. Islet cells were isolated from WT, GTKO and GTKO/hCD55 pigs, and the purity and insulin secretion function were detected. The expression of hCD55 at the DNA, RNA and protein levels was analyzed by agarose gel electrophoresis, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry, respectively. Complement-dependent cytotoxicity assay and complement deposition assay were performed under the incubation conditions with fresh human serum. Results The purity of isolated porcine islet cells from three genotype pigs was > 75%, and the glycemic index was > 1. The expression of hCD55 messenger RNA(mRNA) and protein in GTKO/hCD55 porcine islet cells decreased the deposition of human complement component C3c and membrane-attacking complex C5b-9, and reduced the cytotoxicity. Conclusions The expression of hCD55 protein in porcine islet cells could inhibit the activation of human complement and reduce complement-mediated killing effect, indicating that hCD55 protein could exert complement protection effect on porcine islet cells. These findings provide theoretical basis for the application of hCD55 in islet xenotransplantation.