选择性环氧合酶2抑制剂塞来昔布对人子宫内膜癌细胞的凋亡诱导

Objective To investigate the apoptosis- inductive effects of celecoxib, a selective inhibitor of cyclooxygenase-2 (COX-2), on human endometrial carcinoma cells. Methods After treating human endometrial carcinoma cell HEC-1-B with celecoxib in vitro, apoptosis of HEC-1-B cells was observed by Giemsa staining, flow cytometry and DNA ladder. Semi-quantitative RT-PCR was used to test the expression of COX-2, apoptosis-related Fas and survivin in HEC-1-B. Results Apoptotic morphological changes such as karyopyknosis, nuclear fragmentation and appearance of apoptotic bodies were noted by Giemsa staining after treating HEC-1-B cells with 20 μmol/L celecoxib. Flow cytometry analysis indicated apoptotic rate of HEC-1-B cells was as high as 46.9% after treated with 50 μmol/L celecoxib. Apoptotic peak was found in PI fluorescence histogram. Genome DNA electrophoresis further confirmed the formation of typical apoptotic DNA ladder. After HEC-1-B cells treated with celecoxib, the expression of COX-2 mRNA and apoptosis- related suppressor gene survivin declined, and expression of apoptosis- related gene Fas increased. 50 μmol/L celecoxib impeded detection of survivin expression. Conclusions Celecoxib induces apoptosis of HEC- 1B cells. By inhibiting COX-2 activity, the expression of Fas increases and survivin expression decreases, which may be one of the mechanisms of apoptosis induction.     

Effect of PKC signalling pathway and aldose reductase on expression of fibronectin induced by transforming growth factor-β1 in human mesangial cells

Objective To study the effect of PKC signalling pathway and aldose reductase (AR) on the expression of fibronectin (FN) induced by transforming growth factor-β1 (TGF-β1). Methods Human mesangial cells (HMCs) were cultured and transfected with pcDNA3-AR, and subject to AR gene silencing with small interfering RNA (siRNA) and then the cell was treated with recombinant human TGF-β1. The AR mRNA expression in the HMCs was examined using real time RT-PCR and protein expression of AR and FN was detected by Western blotting. Results The cultured HMC treated with TGF-$l showed increased expression of AR and FN,the normal HMC showed not reduced expression of FN after incubation with single inhibitors of AR. Pre-incubation of cells with inhibitors of AR and PKC, then the different groups of cells were treated with TGF-$l ,and the induction effect on FN expression was suppressed (34%) in HMC. HMCs transfected with AR showed a strong protein expression of FN, which was increased by 3. 6-fold after treatment with TGF-pl (P <0. 05) , and the induction effect on FN expression was suppressed by G(O)6983 (42%) in HMCs (P < 0. 05) . The HMC with AR gene knock-down by siRNA showed a decreased expression of AR and 90% decrease of FN protein in HMCs(P <0. 01) , and TGF-β1-induced up-regulation of FN was significantly suppressed by siRNA (12%) in HMCs (P <0. 01). Conclusions AR is capable of regulating FN expression only in the presence of TGF-β1, and this reaction is possibly accomplished through the activation of PKC signalling pathway.     

Effect of PKC signalling pathway and aldose reductase on expression of fibronectin induced by transforming growth factor-β1 in human mesangial cells

Objective To study the effect of PKC signalling pathway and aldose reductase (AR) on the expression of fibronectin (FN) induced by transforming growth factor-β1 (TGF-β1). Methods Human mesangial cells (HMCs) were cultured and transfected with pcDNA3-AR, and subject to AR gene silencing with small interfering RNA (siRNA) and then the cell was treated with recombinant human TGF-β1. The AR mRNA expression in the HMCs was examined using real time RT-PCR and protein expression of AR and FN was detected by Western blotting. Results The cultured HMC treated with TGF-$l showed increased expression of AR and FN,the normal HMC showed not reduced expression of FN after incubation with single inhibitors of AR. Pre-incubation of cells with inhibitors of AR and PKC, then the different groups of cells were treated with TGF-$l ,and the induction effect on FN expression was suppressed (34%) in HMC. HMCs transfected with AR showed a strong protein expression of FN, which was increased by 3. 6-fold after treatment with TGF-pl (P <0. 05) , and the induction effect on FN expression was suppressed by G(O)6983 (42%) in HMCs (P < 0. 05) . The HMC with AR gene knock-down by siRNA showed a decreased expression of AR and 90% decrease of FN protein in HMCs(P <0. 01) , and TGF-β1-induced up-regulation of FN was significantly suppressed by siRNA (12%) in HMCs (P <0. 01). Conclusions AR is capable of regulating FN expression only in the presence of TGF-β1, and this reaction is possibly accomplished through the activation of PKC signalling pathway.     

Phenotypic Knockout of CXCR4 on Molt-4 with SDF-1α/54 Attached with KDEL

Objective ： To investigate the mechanism of phenotypic knockout of CXCR4 on T-cell leukemia cell line Molt-4 via SDF-1α/54/KDEL intrakine technology, which the mutant SDF-1α/54, human stromal cell-derived Faceor-1 （SDF-1α） was deleted its C- terminal α-helix and attached with a endoplasimc reticulum retention signal 4-peptide- KDEL encoding gene, so that retain the newly synthesized receptor CXCR4 within the Molt-4 cells endoplasmic reticulum. Methods： The recombinant vector pEGFP-C3/SDF- 1α/54/KDEL were transfected into Cos-7 cells by liposome, SDF-1α/54/KDEL fusion protein was confirmed with western blot. The recombinant plasmids were transfected transiently into Molt-4 by electroporation. Results：Western blot confirmed SDF-1α/54/KDEL expression in Cos-7. A dramatic downregulation of CXCR4 expression on Molt-4 was demonstrated by flow cytometric （FCM） analysis. Conelusion：SDF-1α/54/KDEL and SDF- 1αKDEL have no significant deviation for phenotypic knockout of CXCR4. These suggest that the phenotypic knockout effects of SDF-1α/54 against CXCR4 are not influenced by deleting of SDF-1α helix in the C-terminal.     

PD-1 and PD-1 ligands: from discovery to clinical application

Programmed cell death-1 (PD-1, Pdcd1), an immunoreceptor belonging to the CD28/CTLA-4 family negatively regulates antigen receptor signaling by recruiting protein tyrosine phosphatase, SHP-2 upon interacting with either of two ligands, PD-L1 or PD-L2. Because of the wide range of ligand distribution in the body, its biological significance pervades almost every aspect of immune responses including autoimmunity, tumor immunity, infectious immunity, transplantation immunity, allergy and immunological privilege. In this review, we would like to summarize the history of PD-1 research since its discovery and recent findings that suggest promising future for the clinical application of PD-1 agonists and antagonists to various human diseases.     

PD-1 and autoimmunity

An initiating T cell response requires both costimulatory signaling and T cell receptor/MHC binding. The immune system balances positive and negative costimulatory signal pathways to activate and deactivate T cells. This review focuses primarily on PD-1 and its ligands, which form a crucial inhibitory costimulatory pathway for maintaining peripheral tolerance, and their contribution to autoimmunity. Since 1992, when PD-1 was isolated, many studies have described the physiological roles of PD-1 signaling, reported relationships between Pdcd-1 gene polymorphism and autoimmune diseases, and applied PD-1/PD-1 ligand modulation to clinical trials. This review summarizes recent advances and future therapeutic applications of PD-1 and its ligands to autoimmune diseases.     

Emerging PD-1 and PD-1L inhibitors-associated myopathy with a characteristic histopathological pattern

Background and objectiveDrug-induced myopathy is among the most common causes of muscle disease. An association has recently been described between programmed death-1 (PD-1)/PD-1 ligand (PD-L1) inhibitors and immune-related adverse events (irAE) affecting the muscle. Here, we report the clinical and pathological findings of nine unrelated patients with PD-1 and PD-L1 inhibitors-associated myopathy.MethodsWe retrospectively analyzed 317 muscle biopsies performed for diagnostic purposes from January 2017 to June 2019. Patients were attended in two tertiary centers and muscle biopsies were performed and analyzed by two myology experts. Muscle biopsies were frozen in cooled isopenthane, cryostat sectioned and stained. Immunohistochemistry studies were also performed as a routine procedure in our lab.ResultsWe identified 9 patients receiving anti-PD-1 or PD-L1 inhibitors consulting for either muscle weakness, asthenia, myasthenic-like syndrome or other muscle related-symptoms, along with biopsy-proven inflammatory myopathy. One had concomitant myocarditis. In most of the cases muscle biopsy showed a marked phenomenon of necrosis, macrophagy and muscle regeneration with perivascular inflammatory infiltrates with a large component of macrophagic cells. A tendency to perifascicular atrophy was also noticed. The expression of MHC class I antigens predominated in the perifascicular zones. Raised muscle enzymes were detected in 7 patients.ConclusionA characteristic clinic-pathological pattern, including a myasthenia gravis-like syndrome plus myositis was found in patients receiving PD-1 and PD-1 L inhibitors. A large component of macrophages resembling granulomas seems to be the pathological hallmark of the syndrome. Further information is required to understand the wide spectrum of immune-related adverse events involving the muscle during or after treatment with anti-PD-1 inhibitors, but the pathological picture seems to be characteristic.     

PD-1/PD-L1信号通路与肿瘤

程序性死亡因子-1(Programmed death-1,PD-1)及配体(Programmed death ligand-1,PD-L1)作为一组免疫检验点共抑制分子通过激活下游信号通路抑制T细胞的活化、增殖及细胞因子的分泌,诱导效应T细胞凋亡。肿瘤发生时,PD-1/PD-L1表达异常增加,参与肿瘤的免疫逃逸,与肿瘤浸润、转移及病人预后密切相关。抑制PD-1/PD-L1信号通路可逆转T细胞抗肿瘤效应。     

Emerging concepts in PD-1 checkpoint biology

The PD-1 pathway is a cornerstone in immune regulation. While the PD-1 pathway has received considerable attention for its role in contributing to the maintenance of T cell exhaustion in chronic infection and cancer, the PD-1 pathway plays diverse roles in regulating host immunity beyond T cell exhaustion. Here, we discuss emerging concepts in the PD-1 pathway, including (1) the impact of PD-1 inhibitors on diverse T cell differentiation states including effector and memory T cell development during acute infection, as well as T cell exhaustion during chronic infection and cancer, (2) the role of PD-1 in regulating Treg cells, NK cells, and ILCs, and (3) the functions of PD-L1/B7-1 and PD-L2/RGMb/neogenin interactions. We then discuss the emerging use of neoadjuvant PD-1 blockade in the treatment of early-stage cancers and how the timing of PD-1 blockade may improve clinical outcomes. The diverse binding partners of PD-1 and its associated ligands, broad expression patterns of the receptors and ligands, differential impact of PD-1 modulation on cells depending on location and state of differentiation, and timing of PD-1 blockade add additional layers of complexity to the PD-1 pathway, and are important considerations for improving the efficacy and safety of PD-1 pathway therapeutics.     

PD-1/PD-L pathway and autoimmunity

Programmed cell death 1 (PD-1) was isolated in 1992 by subtractive-hybridization technique, as a molecule whose expression is enhanced by apoptotic stimuli. Since then we have been analyzing the function of PD-1 in the regulation of immune responses. Generation of PD-1 deficient mice, pathophysiological analyses of autoimmune diseases in PD-1 deficient mice, identification of two ligands, and analyses of downstream events of PD-1 revealed that PD-1 prevents autoimmunity by inhibiting activation of self-reactive lymphocytes. These findings were further applied on human autoimmune diseases and single nucleotide polymorphisms (SNPs) on human PD-1 gene have been reported to link with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and type I diabetes.     

PD-1 signaling in primary T cells

Summary:  Programmed death-1 (PD-1) is a cell surface molecule that regulates the adaptive immune response. Engagement of PD-1 by its ligands PD-L1 or PD-L2 transduces a signal that inhibits T-cell proliferation, cytokine production, and cytolytic function. While a great deal is known concerning the biologic roles PD-1 plays in regulating the primary immune response and in T-cell exhaustion, comparatively little is known regarding how PD-1 ligation alters signaling pathways. PD-1 ligation is known to inhibit membrane-proximal T-cell signaling events, while ligation of the related inhibitory molecule cytotoxic T-lymphocyte antigen-4 appears to target more downstream signaling pathways. A major obstacle to an in-depth understanding of PD-1 signaling is the lack of physiologic models in which to study signal transduction. This review focuses on: (i) signaling pathways altered by PD-1 ligation, (ii) factors recruited upon PD-1 phosphorylation, and (iii) exploring the hypothesis that PD-1 ligation induces distinct signals during various stages of immune-cell differentiation. Lastly, we describe models to dissect the function of the PD-1 cytoplasmic tail using primary cells in the absence of agonist antibodies.     

PD-1/PD-L pathway and autoimmunity

Programmed cell death 1 (PD-1) was isolated in 1992 by subtractive-hybridization technique, as a molecule whose expression is enhanced by apoptotic stimuli. Since then we have been analyzing the function of PD-1 in the regulation of immune responses. Generation of PD-1 deficient mice, pathophysiological analyses of autoimmune diseases in PD-1 deficient mice, identification of two ligands, and analyses of downstream events of PD-1 revealed that PD-1 prevents autoimmunity by inhibiting activation of self-reactive lymphocytes. These findings were further applied on human autoimmune diseases and single nucleotide polymorphisms (SNPs) on human PD-1 gene have been reported to link with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and type I diabetes.