Ferroptosis, a new form of programmed cell death marked by iron-dependent phospholipid peroxidation, is regulated by complex cellular metabolic pathways, including iron metabolism, lipid metabolism, and oxidation-reduction system, is associated with many organ injuries and degeneration, and has great potential in the treatment of ischemic diseases and lipid peroxide-related degenerative diseases. Myocardial ischemia reperfusion injury (MIRI) is the most common cause of death in patients with acute myocardial infarction after revascularization therapy. Recent studies have shown that ferroptosis is intimately related to the pathological process of MIRI. Ferroptosis is associated with MIRI through oxidative stress, iron metabolism, lipid metabolism, endoplasmic reticulum stress and inflammatory response. Intervention of ferroptosis during reperfusion can effectively improve cardiac function and reduce myocardial infarct size. In this paper, the research progress was explored between ferroptosis and MIRI, and the specific role of ferroptosis in MIRI was discussed.

Objective:To explore the clinical efficacy and risk factors of umbilical cord mesenchymal stem cells (UCMSCs) infusion at an early stage (i.e.gross hematuria) for hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods:The relevant clinical data were retrospectively reviewed for 300 patients undergoing allo-HSCT from January 2016 to July 2021.According to the presence or absence of HC, they were assigned into two groups of HC (n=89) and non-HC (control, n=211). According to whether or not receiving an infusion of UCMSCs, 51 patients of HC degree Ⅱ-Ⅳ were divided into two groups of UCMSC infusion and non-infusion.The risk factors of HC after allo-HSCT were analyzed by χ2 test.Logistic regression was employed for multivariate analysis of P<0.05.Mann-Whitney U test was utilized for statistically analyzing the duration of gross hematuria and urinary tract irritation symptoms and evaluating the clinical efficacy of UCMSCs infusion for HC. Results:Among them, 89 (29.67%) developed HC post-allo-HSCT.Clinical grades were Ⅰ (n=38, 42.70%), Ⅱ (n=36, 40.45%), Ⅲ (n=13, 14.61%) and Ⅳ (n=2, 2.25%). The median occurrence time was 29 (21.5-35.0) days post-allo-HSCT.In univariate analysis, age ≤30 years, haploid transplantation, antithymocyte globulin (ATG), acute graft-versus-host disease (aGVHD), CMV-DNA positive pretreatment significantly boosted the risk of HC ( P<0.05). In multivariate analysis, aGVHD was an independent risk factor for HC ( OR=10.281, 95% CI: 1.606-65.813, P=0.014). Among 89 HC patients, 38 grade Ⅰ patients were complete remission(CR). Among 51 patients of grade Ⅱ-Ⅳ HC, the outcomes were CR (n=48) and non-remission(NR)(n=3). And 24/51 of them received UCMSCs plus conventional treatment.The duration of gross hematuria was shorter in UCMSCs infusion group than that in UCMSCs non-infusion group [12(9-17) vs 17(12.0-26.5) day] and the difference was statistically significant ( P=0.045). And the duration of urinary tract irritation symptoms was shorter in UCMSCs infusion group than that in UCMSCs non-infusion group [18(11-30) vs 27(18.0-35.5) days] and the difference was statistically significant ( P=0.048). Conclusions:Indicated for post-ALLO-HSCT HC, infusion of UCMSCs may significantly shorten the course of disease.Age ≤30 years, haploid transplantation and preconditioning with positive ATG, aGVHD and CMV-DNA may boost the risks of HC post-allo-HSCT.And aGVHD is an independent risk factor for HC after allo-HSCT.

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[Abstract] Objective: To develop a new type of CD7 chimeric antigen receptor modified T cell (CD7-CAR-T) for the treatment of CD7 positive acute myeloid leukemia (AML), and to observe its killing effect on CD7 positive AML cells. Methods: The CD7-CAR lentiviral vector was constructed based on the CD7 Nanobody sequence and costimulatory domain sequence of CD28 and 4-1BB. The lentiviral particles were packaged and used to co-transfect human T cells with protein expression blocker (PEBL), so as to prepare CD7- CAR-T cells. Real time cellular analysis (RTCA) was used to monitor the cytotoxicity of CD7-CAR-T cells on CD7 overexpressed 293T cells. Flow cytometry assay was used to detect the effect of CD7-CAR-T cells on proliferation and cytokine secretion of AML cells with high, medium and low CD7 expressions (KG-1, HEL and Kasumi-1 cells, respectively). Results: CD7-CAR-T cell was successfully constructed and its surface expression of CD7 was successfully blocked. Compared with T cells, CD7-CAR-T cells could significantly inhibit the proliferation of CD7-293T cells and promote the release of TNF, Granzyme B and INF-γ; in addition, CD7-CAR-T cells also significantly promoted the apoptosis (t=147.1, P<0.01; t=23.57, P<0.01) and cytokine release (P<0.05 or P<0.01) in CD7 positive KG-1 and HEL cells, but had little effect on Kasumi-1 cells that only expressed minimal CD7 antigen (t=0.7058, P>0.05). Conclusion: CD7-CAR-T cells can specifically kill CD7-positive AML cells in vitro.

Objective:To prepare nanobody-based immunotoxin BI7D12-PE38KDEL targeting EGFR and to examine its cytotoxicity against EGFR positive tumor cells.Methods:By using molecular cloning strategy,prokaryotic expression construct of pET28a-BI7D12-PE38KDEL was generated which consisted of nanobody 7D12 targeting EGFR in the form of a divalent fused with PE38KDEL,a truncated form of pseudomonas exotoxin A via a flexible peptide(G4S)4,and then transformed into E.coli BL21(DE3).Protein expression was induced by adding IPTG,purified by Ni-affinity column chromatography,and verified by Western blot.The binding capacity of the resulted immunotoxin to EGFR-positive cells A549,HT29,MCF-7 and EGFR-negative cells CEM,Jurkat were determined by flow cytometry assay,and its cytotoxicity against the target cells was examined.Briefly,tumor cells were treated with different dosage of the immunotoxin,and the killing efficacy of BI7D12-PE38KDEL on these cells were assessed by WST-1 assay after 72 hours.Results:The SDS-PAGE and Western blot results showed the recombinant immunotoxin BI7D12-PE38KDEL was successfully prepared,and majority of them was expressed in soluble form.BI7D12-PE38KDEL could selectively bind to EGFR-positive cells of A549,HT29,and MCF-7.More importantly,the immunotoxin exhibited much more significant killing effect on these EGFR positive cells compared to the negative control group of CEM and Jurkat cells(P<0.01).Conclusion:In the current study,the nanobody-based immunotoxin BI7D12-PE38KDEL targeting EGFR was successfully prepared and exhibited a superior inhibition effect for the growth of EGFR-positive cells.

Objective To investigate the effect of N-acetylcysteine ( NAC) on lung and heart injury of rats with a fast floating escape induced decompression sickness .Methods Eighty male Sprague-Dawley rats were randomly and evenly divided into four groups:control group and three NAC prevention groups .The NAC groups were treated with different doses of NAC(250, 500 or 1000 mg/kg)by intraperitoneal injection 1 h before entrance.In the control group, rats were given an equal volume of saline1h before entrance.The air was pressurized at the 2t/7 exponential rate to 1.5 MPa which was maintained for 4 min and then uniformly decompressed to atmospheric pressure .The extravehicular survival and pathological changes in the lung and heart tissue were detected 0.5 h after rat egress.Results The survival rate of rats treated with NAC 500 mg/kg(90%) was significantly higher than that of those treated with saline (65%)alone (P<0.05).There was large break and fusion in the structure of pulmonary alveolus of control group besides obvious erythrocyte exudation , cardiac muscle fibers edema ,and obvious denaturation and break .Conclusion NAC can play a protective role in rats with a fast floating escape induced decompression sickness by mitigating the injury to and inflammation of lung and heart tissue .

Objective To investigate the intervention of chemokine receptor 4(CXCR4) antagonist AMD3100 in lung tissues of rats during pulmonary oxygen intoxication.Methods Forty SD rats were randomly divided into 4 groups:normal pressure air PBS group, normal pressure air antagonist group , oxygen exposure PBS group and oxygen exposure antagonist group, each consisting of 10 animals.The last two groups were compressed to 0.23 MPa at an exponential rate of 0.1 MPa/min by pure oxygen.Pathological changes of lung tissues were observed by hematoxylin eosin stain.Changes in TNF-αand IL-1βexpression levels in the lung tissues of rats were detected by ELISA.Changes in CXCR4 expression levels were ob-served by Western blotting.Results Pathological examination indicated that edema and hemorrhage in the alveolar and pulmonary interstitial tissue of oxygen exposure antagonist group were lighter than in oxygen exposure PBS group.The levels of TNF-α, IL-1βand cleaved-caspase-3 in the lung tissues of the oxygen exposure antagonist group were lower than in oxy-gen exposure PBS group.Conclusion Blocking CXCR4 with AMD3100 can effectively alleviate lung injury during pulmo-nary oxygen intoxication.

Objective To study the effect of nicardipine on fast floating escape induced lung injury in animal models with decompression sickness .Methods Sixty male SD rats were randomly and evenly divided into three groups:blank control, control and nicardipine groups .The nicardipine group was given nicardipine 50 mg/kg orally 0.5 h before entrance.In the control group, rats were given an equal volume of saline 0.5 h before entrance.The blank control group only stayed in the vehicle without any pressurized procedure .The air was pressurized at the 2t/7 exponential rate to 1.5 Mpa which was maintained for 4 min, and then uniformly decompressed to atmospheric pressure .The extravehicular survival and lung pathology were observed in rats after 0.5 h, IL1-βand TNF-αexpression levels were detected by ELISA , and the Caspase 3 expression in lung tissue was detected by Western blot .Results The incidence and mortality rate were 80%and 50%respectively in control group ,and 100%and 80%in the experimental group .The surviving animals in the two groups suffered from alveolar and interstitial lung hemorrhage , with widened interstitial lung .IL1-βin the experimental group was significantly higher than in the normal control group , while TNF-αhad no significant change .After nicardipine treatment pro-caspase 3 did not change significantly , but cleaved-caspase 3 increased significantly .Conclusion Nicardipine can aggravate lung injury caused by fast floating escape-induced decompression sickness if used before decompression.

Objective To investigate the effect of PPAR-δ on the lung injury of rats induced by hyperbaric oxygen (HBO2) exposure.Methods Sixty male Sprague-Dawley rats were randomly divided into six groups:air+vehicle, air+GW0742, and air+GSK0660, HBO2 +vehicle, HBO2 +GW0742, HBO2 +GSK0660.Lung injury was induced in rats by HBO2exposure (2.3 ATA, 100%O2, 8 h).Rats were injected with vehicle[10%DMSO in 0.3 ml NaCl 0.9%(v/v)] or GW0742 (0.3 mg/kg, ip) or GSK0660 (1 mg/kg, ip) at 1, 6 and 12 hours before either air or oxygen exposure .Protein levels in the bronchoalveolar lavage fluid ( BALF) , wet/dry ratio of the lung and the pathological changes in the lung tissue were detected 30 min after rats′egress.Results and Conclusion For the HBO2 +GW0742 group, the protein levels in BALF, the wet/dry ratio of the lung and the pathological changes in lung tissues all significantly decreased compared with those of the air group .These changes in HBO 2 +GSK0660 group tended to increase the level of lung injury .PPAR-δhas a protective effect on pulmonary oxygen toxicity induced by HBO 2 .