The lectin Siglec-G inhibits dendritic cell cross-presentation by impairing MHC class I-peptide complex formation.

CD8α(+) dendritic cells (DCs) are specialized at cross-presenting extracellular antigens on major histocompatibility complex (MHC) class I molecules to initiate cytotoxic T lymphocyte (CTL) responses; however, details of the mechanisms that regulate cross-presentation remain unknown. We found lower expression of the lectin family member Siglec-G in CD8α(+) DCs, and Siglec-G deficient (Siglecg(-/-)) mice generated more antigen-specific CTLs to inhibit intracellular bacterial infection and tumor growth. MHC class I-peptide complexes were more abundant on Siglecg(-/-) CD8α(+) DCs than on Siglecg(+/+) CD8α(+) DCs. Mechanistically, phagosome-expressed Siglec-G recruited the phosphatase SHP-1, which dephosphorylated the NADPH oxidase component p47(phox) and inhibited the activation of NOX2 on phagosomes. This resulted in excessive hydrolysis of exogenous antigens, which led to diminished formation of MHC class I-peptide complexes for cross-presentation. Therefore, Siglec-G inhibited DC cross-presentation by impairing such complex formation, and our results add insight into the regulation of cross-presentation in adaptive immunity.

The microRNA miR-29 controls innate and adaptive immune responses to intracellular bacterial infection by targeting interferon-γ.

Interferon-γ (IFN-γ) has a critical role in immune responses to intracellular bacterial infection. MicroRNAs (miRNAs) are important in the regulation of innate and adaptive immunity. However, whether miRNAs can directly target IFN-γ and regulate IFN-γ production post-transcriptionally remains unknown. Here we show that infection of mice with Listeria monocytogenes or Mycobacterium bovis bacillus Calmette-Guérin (BCG) downregulated miR-29 expression in IFN-γ-producing natural killer cells, CD4(+) T cells and CD8(+) T cells. Moreover, miR-29 suppressed IFN-γ production by directly targeting IFN-γ mRNA. We developed mice with transgenic expression of a 'sponge' target to compete with endogenous miR-29 targets (GS29 mice). We found higher serum concentrations of IFN-γ and lower L. monocytogenes burdens in L. monocytogenes-infected GS29 mice than in their littermates. GS29 mice had enhanced T helper type 1 (T(H)1) responses and greater resistance to infection with BCG or Mycobacterium tuberculosis. Therefore, miR-29 suppresses immune responses to intracellular pathogens by targeting IFN-γ.

Large-cohort humanized NPI mice reconstituted with CD34+ hematopoietic stem cells are feasible for evaluating preclinical cancer immunotherapy.

Cancer immunotherapy has achieved impressive therapeutic effects in many cancers, while only a small subset of patients benefit from it and some patients even have experienced severe toxicity. It is urgent to develop a feasible large-cohort humanized mouse model to evaluate the pre-clinical efficacy and safety of cancer immunotherapy. Furthermore, developing potentially effective combination therapy between cancer immunotherapy and other therapies also needs humanized mouse model to adequately mimic clinical actual setting. Herein, we established a humanized mouse model engrafted with less human CD34+ HSCs than ever before and then evaluated reconstitution efficiency and the profiles of human immune cells in this humanized mouse model. Also, this humanized mouse model was used to evaluate the preclinical efficacy and safety of cancer immunotherapy. For each batch of CD34+ HSCs humanized mouse model, a relatively-large cohort with over 25% human CD45+ cells in peripheral blood was established. This humanized mouse model could efficiently reconstitute human innate and adaptive immune cells. This humanized mouse model supported patient-derived xenograft tumor growth and tumor infiltration of PD-1+ human T cells. Furthermore, therapeutic efficacy, re-activation of tumor-infiltrated T cells, and side effects of checkpoint blockade therapy could be monitored in this humanized mouse model. Human T cells from this humanized mouse model were successfully engineered with CD19-CAR. CD19 CAR-T cells could effectively deplete B cells and suppress tumor growth of acute lymphoblastic leukemia in vivo in this humanized mouse model. This humanized mouse model also could be used to demonstrate the efficacy of bispecific antibodies, such as anti-CD19/CD3. Overall, our work provides a feasible large-cohort humanized mouse model for evaluating a variety of cancer immunotherapy approaches including checkpoint inhibitors, adoptive cell therapy, and bispecific antibody therapy, and demonstrates that human T cells from this humanized mouse model possess anti-tumor activities in vitro and in vivo.

Mutant p53R211* ameliorates inflammatory arthritis in AIA rats via inhibition of TBK1-IRF3 innate immune response.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune inflammation disease characterized by imbalance of immune homeostasis. p53 mutants are commonly described as the guardian of cancer cells by conferring them drug-resistance and immune evasion. Importantly, p53 mutations have also been identified in RA patients, and this prompts the investigation of its role in RA pathogenesis. METHODS: The cytotoxicity of disease-modifying anti-rheumatic drugs (DMARDs) against p53 wild-type (WT)/mutant-transfected RA fibroblast-like synoviocytes (RAFLSs) was evaluated by MTT assay. Adeno-associated virus (AAV) was employed to establish p53 WT/R211* adjuvant-induced arthritis (AIA) rat model. The arthritic condition of rats was assessed by various parameters such as micro-CT analysis. Knee joint samples were isolated for total RNA sequencing analysis. The expressions of cytokines and immune-related genes were examined by qPCR, ELISA assay and immunofluorescence. The mechanistic pathway was determined by immunoprecipitation and Western blotting in vitro and in vivo. RESULTS: Among p53 mutants, p53R213* exhibited remarkable DMARD-resistance in RAFLSs. However, AAV-induced p53R211* overexpression ameliorated inflammatory arthritis in AIA rats without Methotrexate (MTX)-resistance, and our results discovered the immunomodulatory effect of p53R211* via suppression of T-cell activation and T helper 17 cell (Th17) infiltration in rat joint, and finally downregulated expressions of pro-inflammatory cytokines. Total RNA sequencing analysis identified the correlation of p53R211* with immune-related pathways. Further mechanistic studies revealed that p53R213*/R211* instead of wild-type p53 interacted with TANK-binding kinase 1 (TBK1) and suppressed the innate immune TBK1-Interferon regulatory factor 3 (IRF3)-Stimulator of interferon genes (STING) cascade. CONCLUSIONS: This study unravels the role of p53R213* mutant in RA pathogenesis, and identifies TBK1 as a potential anti-inflammatory target.

The E3 ubiquitin ligase Nrdp1 'preferentially' promotes TLR-mediated production of type I interferon.

E3 ubiquitin ligases are important in both innate and adaptive immunity. Here we report that Nrdp1, an E3 ubiquitin ligase, inhibited the production of proinflammatory cytokines but increased interferon-beta production in Toll-like receptor-triggered macrophages by suppressing adaptor MyD88-dependent activation of transcription factors NF-kappaB and AP-1 while promoting activation of the kinase TBK1 and transcription factor IRF3. Nrdp1 directly bound and polyubiquitinated MyD88 and TBK1, which led to degradation of MyD88 and activation of TBK1. Knockdown of Nrdp1 inhibited the degradation of MyD88 and the activation of TBK1 and IRF3. Nrdp1-transgenic mice showed resistance to lipopolysaccharide-induced endotoxin shock and to infection with vesicular stomatitis virus. Our data suggest that Nrdp1 functions as both an adaptor protein and an E3 unbiquitin ligase to regulate TLR responses in different ways.

Comparison of 4- and 4 plus-courses S-1 administration as adjuvant chemotherapy for pancreatic ductal adenocarcinoma.

PURPOSE: The study aimed to investigate the potential benefit of more than 4 courses of S1 adjuvant chemotherapy for patients with pancreatic ductal adenocarcinoma (PDAC) after surgery. METHOD: Data were retrospectively collected from consecutive patients who underwent S-1 adjuvant chemotherapy following curative pancreatectomy between January 2016 and December 2018. Four-courses and > 4 courses cohorts were compared for overall survival (OS) as a primary outcome, and relapse-free survival (RFS) and adverse event incidence as secondary outcomes. RESULTS: Four-courses and > 4 courses cohorts comprised 99 patients and 64 ones, respectively. TNM stage (stage II vs. I: HR, 2.125; 95% CI, 1.164-4.213; P = 0.015), duration of S-1 administration (4 vs. > 4 courses: HR, 3.113; 95% CI, 1.531-6.327; P = 0.002) and tumor grade (G3 vs. G1/2: HR, 3.887; 95% CI, 1.922-7.861; P < 0.001) were independent prognostic factors. Under the condition of patients' survival time beyond 8 months, the OS of patients in > 4 courses cohort was significantly prolonged compared with that of 4 courses cohort (4 vs. > 4 courses: HR, 2.284; 95% CI, 1.197-4.358; P = 0.012), especially for patients in TNM stageII (4 vs. > 4 courses: HR, 2.906; 95% CI, 1.275-6.623; P = 0.011).RFS and adverse events incidence did not signifcantly difer between both cohorts. CONCLUSION: Prolonged duration of S-1 intake is beneficial to prognosis of patients with PDAC resection.

Preoperative detection of KRAS G12D mutation in ctDNA is a powerful predictor for early recurrence of resectable PDAC patients.

BACKGROUND: About 25-37% of resectable pancreatic ductal adenocarcinoma (PDAC) had a great chance of early recurrence after radical resection, which is mainly due to preoperative micrometastasis. We herein demonstrated the profiles of ctDNA in resectable PDAC and use of ctDNA to identify patients with potential micrometastasis. METHODS: A total of 113 and 44 resectable PDACs were enrolled in discovery and validation cohorts, separately. A panel containing 50 genes was used to screen ctDNA by an NGS-based assessment with high specificity. RESULTS: In the discovery cohort, the overall detection rate was 38.05% (43/113). Among positive ctDNA, KRAS mutation had the highest detection rate (23.01%, 26/113), while the others were <5%. Survival analysis showed that plasma KRAS mutations, especially KRAS G12D mutation, had significant association with OS and RFS of resectable PDAC. Plasma KRAS G12D mutation showed a strong correlation with early distant metastasis. In the validation cohort, survival analysis showed similar association between plasma KRAS G12D mutation and poor outcomes. CONCLUSIONS: This study demonstrated that plasma KRAS mutations, especially KRAS G12D mutation, served as a useful predictive biomarker for prognosis of resectable PDAC. More importantly, due to high correlation with micrometastasis, preoperative detection of plasma KRAS G12D mutation helps in optimising surgical selection of resectable PDAC.

Blockade of CD47 ameliorates autoimmune inflammation in CNS by suppressing IL-1-triggered infiltration of pathogenic Th17 cells.

The migration of Th17 cells into central nervous system (CNS) tissue is the key pathogenic step in experimental autoimmune encephalomyelitis (EAE) model. However, the mechanism underlying the pathogenic Th17 cell migration remains elusive. Here we report that blockade of CD47 with CD47-Fc fusion protein is effective in preventing and curing EAE by impairing infiltration of Th17 cells into CNS. However, CD47 deficiency does not directly impair the migration of Th17 cells. Mechanistic studies showed that CD47 deficiency inhibited degradation of inducible nitric oxide synthase (iNOS) in proteasome of macrophages by Src activation and led to the increased nitric oxide (NO) production. Then NO suppressed inflammasome activation-induced IL-1ß production. This lower IL-1ß reduces the expression of IL-1R1 and migration-related chemokine receptors on CD47(-/-) Th17 cells, inhibiting the ability of Th17 cells to infiltrate into the CNS of CD47(-/-) mice and therefore suppressing EAE development. In vivo administration of exogenous IL-1ß indeed promoted the infiltration CD47(-/-) Th17 cells into CNS and antagonized the protective role of CD47 deficiency in EAE pathogenesis. Our results demonstrate a potential preventive and therapeutic application of CD47 blockade in controlling EAE development.

Splenic stroma-educated regulatory dendritic cells induce apoptosis of activated CD4 T cells via Fas ligand-enhanced IFN-γ and nitric oxide.

Stromal microenvironments of bone marrow, lymph nodes, and spleen have been shown to be able to regulate immune cell differentiation and function. Our previous studies demonstrate that splenic stroma could drive mature dendritic cells (DC) to further proliferate and differentiate into regulatory DC subset that could inhibit T cell response via NO. However, how splenic stroma-educated regulatory DC release NO and whether other molecules are involved in the suppression of T cell response remain unclear. In this study, we show that splenic stroma educates regulatory DC to express high level of Fas ligand (FasL) by TGF-ß via ERK activation. The findings, that inhibition of CD4 T cell proliferation by regulatory DC required cell-to-cell contact and FasL deficiency impaired inhibitory effect of regulatory DC, indicate that regulatory DC inhibit CD4 T cell proliferation via FasL. Then, regulatory DC have been found to be able to induce apoptosis of activated CD4 T cells via FasL in caspase 8- and caspase 3-dependent manner. Interestingly, FasL on regulatory DC enhanced IFN-γ production from activated CD4 T cells, and in turn T cell-derived IFN-γ induced NO production from regulatory DC, working jointly to induce apoptosis of activated CD4 T cells. Blockade of IFN-γ and NO could reduce the apoptosis induction. Therefore, our results demonstrated that splenic stroma-educated regulatory DC induced T cell apoptosis via FasL-enhanced T cell IFN-γ and DC NO production, thus outlining a new way for negative regulation of T cell responses and maintenance of immune homeostasis by regulatory DC and splenic stromal microenvironment.

Regulatory dendritic cells program generation of interleukin-4-producing alternative memory CD4 T cells with suppressive activity.

The heterogeneity and mechanisms for the generation of CD4 memory T (CD4 Tm) cells remain elusive. Distinct subsets of dendritic cells (DCs) have been found to regulate a distinct T-helper (Th)-cell subset differentiation by influencing cytokine cues around CD4 T cells; however, whether and how the regulatory DC subset can regulate Tm-cell differentiation remains unknown. Further, there is no ideal in vitro experimental system with which to mimic the 3 phases of the CD4 T-cell immune response (expansion, contraction, memory generation) and/or to culture CD4 Tm cells for more than a month. By analyzing CD4 T cells programmed by long-term coculture with regulatory DCs, we identified a population of long-lived CD4 T cells with a CD44(hi)CD62L(-)CCR7(-) effector memory phenotype and rapid, preferential secretion of the Th2 cytokines interleukin-4 (IL-4), IL-5, IL-10, and IL-13 after antigenic stimulation. These regulatory DC-programmed Tm cells suppress CD4 T-cell activation and proliferation in vitro via IL-10 and inhibit the delayed-type hypersensitivity response once infused in vivo. We also identify their natural counterpart, which is up-regulated by regulatory DC transfusion and negatively regulates the recall response in vivo. Different from interferon-γ-producing conventional Tm cells, these IL-4-producing CD4 Tm cells act as alternative Tm cells with a regulatory function, suggesting a new way of negative immune regulation by memory T cells.

Modified artery-first approach for distal pancreatectomy with celiac axis resection.

BACKGROUND: The superior mesenteric artery-first approach has been proved superior in pancreatoduodenectomy compared with the standard procedure. It is unclear whether similar benefits could be obtained in distal pancreatectomy with celiac axis resection. METHODS: Perioperative and survival outcomes of patients who underwent distal pancreatectomy with celiac axis resection with the modified artery-first approach or traditional approach between January 2012 and September 2021 were compared. RESULTS: The entire cohort comprised 106 patients (modified artery-first approach, n = 35; traditional approach, n = 71). The most common complication was postoperative pancreatic fistula (n = 18, 17.0 per cent), followed by ischaemic complications (n = 17, 16.0 per cent) and surgical site infection (n = 15, 14.0 per cent). Intraoperative blood loss (400 versus 600 ml, P = 0.017) and intraoperative transfusion rate (8.6 versus 29.6 per cent, P = 0.015) were lower in the modified artery-first approach group compared with the traditional approach group. A higher number of harvested lymph nodes (18 versus 13, P = 0.030) and R0 resection rate (88.6 versus 70.4 per cent, P = 0.038) and a lower incidence of ischaemic complications (5.7 versus 21.1 per cent, P = 0.042) was observed in the modified artery-first approach group compared with the traditional approach group. In multivariable analysis, the modified artery-first approach (OR 0.006, 95 per cent c.i., 0 to 0.447; P = 0.020) was protective against ischaemic complications. CONCLUSIONS: Compared with the traditional approach, the modified artery-first approach was associated with lower blood loss and fewer ischaemic complications, and a higher number of harvested lymph nodes and R0 resection rate. Thus, it might improve the safety, staging and prognosis of distal pancreatectomy with celiac axis resection for pancreatic cancer.

N-Acetylcysteine overcomes epalrestat-mediated increase of toxic 4-hydroxy-2-nonenal and potentiates the anti-arthritic effect of epalrestat in AIA model.

Epalrestat, an aldose reductase inhibitor (ARI), has been clinically adopted in treating diabetic neuropathy in China and Japan. Apart from the involvement in diabetic complications, AR has been implicated in inflammation. Here, we seek to investigate the feasibility of clinically approved ARI, epalrestat, for the treatment of rheumatoid arthritis (RA). The mRNA level of AR was markedly upregulated in the peripheral blood mononuclear cells (PBMCs) of RA patients when compared to those of healthy donors. Besides, the disease activity of RA patients is positively correlated with AR expression. Epalrestat significantly suppressed lipopolysaccharide (LPS) induced TNF-α, IL-1ß, and IL-6 in the human RA fibroblast-like synoviocytes (RAFLSs). Unexpectedly, epalrestat treatment alone markedly exaggerated the disease severity in adjuvant induced arthritic (AIA) rats with elevated Th17 cell proportion and increased inflammatory markers, probably resulting from the increased levels of 4-hydroxy-2-nonenal (4-HNE) and malondialdehyde (MDA). Interestingly, the combined treatment of epalrestat with N-Acetylcysteine (NAC), an anti-oxidant, to AIA rats dramatically suppressed the production of 4-HNE, MDA and inflammatory cytokines, and significantly improved the arthritic condition. Taken together, the anti-arthritic effect of epalrestat was diminished or even overridden by the excessive accumulation of toxic 4-HNE or other reactive aldehydes in AIA rats due to AR inhibition. Co-treatment with NAC significantly reversed epalrestat-induced upregulation of 4-HNE level and potentiated the anti-arthritic effect of epalrestat, suggesting that the combined therapy of epalrestat with NAC may sever as a potential approach in treating RA. Importantly, it could be regarded as a safe intervention for RA patients who need epalrestat for the treatment of diabetic complications.

Age-related self-DNA accumulation may accelerate arthritis in rats and in human rheumatoid arthritis.

The incidence of rheumatoid arthritis (RA) is increasing with age. DNA fragments is known to accumulate in certain autoimmune diseases, but the mechanistic relationship among ageing, DNA fragments and RA pathogenesis remain unexplored. Here we show that the accumulation of DNA fragments, increasing with age and regulated by the exonuclease TREX1, promotes abnormal activation of the immune system in an adjuvant-induced arthritis (AIA) rat model. Local overexpression of TREX1 suppresses synovial inflammation in rats, while conditional genomic deletion of TREX1 in AIA rats result in higher levels of circulating free (cf) DNA and hence abnormal immune activation, leading to more severe symptoms. The dysregulation of the heterodimeric transcription factor AP-1, formed by c-Jun and c-Fos, appear to regulate both TREX1 expression and SASP induction. Thus, our results confirm that DNA fragments are inflammatory mediators, and TREX1, downstream of AP-1, may serve as regulator of cellular immunity in health and in RA.

IL-17A-producing gammadeltaT cells promote CTL responses against Listeria monocytogenes infection by enhancing dendritic cell cross-presentation.

Interleukin-17A-producing T cells, especially Th17, have been shown to be involved in inflammatory autoimmune diseases and host defense against extracellular infections. However, whether and how IL-17A or IL-17A-producing cells can help protection against intracellular bacteria remains controversial, especially how it regulates the adaptive immunity besides recruitment of neutrophils in the innate immune system. By infecting IL-17A-deficient mice with Listeria monocytogenes, we show in this study that IL-17A is required for the generation of Ag-specific CD8(+) CTL response against primary infection, but not for the generation of memory CD8(+) T cells against secondary challenge. Interestingly, we identify γδT cells, but not conventional CD4(+) Th17 cells, as the main cells for innate IL-17A production during L. monocytogenes infection. Furthermore, γδT cells are found to promote Ag-specific CD8(+) T cell proliferation by enhancing cross-presentation of dendritic cells through IL-17A. Adoptive transfer of Il17a(+/+) γδT cells, but not Il17a(-/-) γδT cells or Il17a(+/+) CD4(+) T cells, were sufficient to recover dendritic cells cross-presentation and defective CD8(+) T cell response in Il17a(-/-) mice. Our findings indicate an important role of infection-inducible IL-17A-producing γδT cells and their derived IL-17A against intracellular bacterial infection, providing a mechanism of IL-17A for regulation of innate and adaptive immunity.

The Role and Mechanisms of Action of Natural Compounds in the Prevention and Treatment of Cancer and Cancer Metastasis.

Cancer has emerged as one of the world's most concerning health problems. The progression and metastasis mechanisms of cancer are complex, including metabolic disorders, oxidative stress, inflammation, apoptosis, and intestinal microflora disorders. These pose significant challenges to our efforts to prevent and treat cancer and its metastasis. Natural drugs have a long history of use in the prevention and treatment of cancer. Many effective anti-tumor drugs, such as Paclitaxel, Vincristine, and Camptothecin, have been widely prescribed for the prevention and treatment of cancer. In recent years, a trend in the field of antitumor drug development has been to screen the active antitumor ingredients from natural drugs and conduct in-depth studies on the mechanisms of their antitumor activity. In this review, high-frequency keywords included in the literature of several common Chinese and English databases were analyzed. The results showed that five Chinese herbal medicines (Radix Salviae, Panax Ginseng C. A. Mey, Hedysarum Multijugum Maxim, Ganoderma, and Curcumaelongae Rhizoma) and three natural compounds (quercetin, luteolin, and kaempferol) were most commonly used for the prevention and treatment of cancer and cancer metastasis. The main mechanisms of action of these active compounds in tumor-related research were summarized. Finally, we found that four natural compounds (dihydrotanshinone, sclareol, isoimperatorin, and girinimbin) have recently attracted the most attention in the field of anti-cancer research. Our findings provide some inspiration for future research on natural compounds against tumors and new insights into the role and mechanisms of natural compounds in the prevention and treatment of cancer and cancer metastasis.

Involvement of endothelial progenitor cells in blood flow recovery through activation of the Wnt/ß-catenin signaling pathway and inhibition of high oxidative stress in diabetic hindlimb ischemic rats.

BACKGROUND: Diabetes mellitus (DM) often causes stenosis and occlusion of hindlimb blood vessels, which are also the main cause for hindlimb ischemia in elderly people. OBJECTIVES: To investigate the therapeutic effect of endothelial progenitor cell (EPC) transplantation on diabetic hindlimb ischemia. MATERIAL AND METHODS: Endothelial progenitor cells were separated, labeled with PKH-26 and transplanted into rat models (107 cells/100 g). Dichlorodihydrofluorescein diacetate (DCFH-DA) was used to detect any oxidative stress. Streptozotocin (STZ) was injected to establish a diabetic rat model and hindlimb ischemia model was established via operation. Western blotting was used to detect total ß-catenin (T-ß-catenin) and non-phospho-ß-catenin (NP-ß-catenin) levels. The malondialdehyde (MDA), superoxide dismutase (SOD), Wnt3a, Wnt5a and Wnt7a levels were detected using enzyme-linked immunosorbent assay (ELISA). Oxidative stress was measured using DCFH-DA and dihydroethidium (DHE). The endothelial biomarker CD31 was observed to highlight vessels, and PKH-26 to trace migration/adhesion of EPCs. RESULTS: Endothelial progenitor cells were successfully isolated and identified, and diabetic hindlimb ischemic rat models were created. Tempol remarkably improved blood flow in diabetic hindlimb ischemic rats compared to DM+EPCs rats at 14 days (p < 0.001) and 28 days post-operation (p < 0.001). High oxidative stress was observed in diabetic hindlimb ischemic rats. Tempol significantly inhibited oxidative stress levels in diabetic hindlimb ischemic rats. Furthermore, Tempol significantly promoted angiogenesis in diabetic hindlimb ischemic rats compared to DM+EPCs rats. The ß-catenin inhibitor, XAV (DM+EPCs+Tempol+XAV group), significantly suppressed blood flow recovery and angiogenesis in diabetic hindlimb ischemic rats when compared to the DM+EPCs+Tempol group at 14 days (p = 0.026) and 28 days (p < 0.001). The XAV remarkably reduced T-ß-catenin (p < 0.001) and N-ß-catenin (p = 0.030) levels in Tempol-treated diabetic hindlimb ischemic rats, as compared to the DM+EPCs+Tempol group. The Wnt5a participated in the pathology of diabetic hindlimb ischemia. CONCLUSIONS: There are high oxidative stress levels in both EPCs in high-glucose environments and diabetic hindlimb ischemia, which can lead to limited blood flow recovery. The high oxidative stress caused the inhibition of Wnt/ß-catenin signaling pathway, leading to limited blood flow recovery in diabetic hindlimb ischemia. At the same time, Wnt5a participated in the EPC-mediated blood flow recovery.

Integrated profiling of human pancreatic cancer organoids reveals chromatin accessibility features associated with drug sensitivity.

Chromatin accessibility plays an essential role in controlling cellular identity and the therapeutic response of human cancers. However, the chromatin accessibility landscape and gene regulatory network of pancreatic cancer are largely uncharacterized. Here, we integrate the chromatin accessibility profiles of 84 pancreatic cancer organoid lines with whole-genome sequencing data, transcriptomic sequencing data and the results of drug sensitivity analysis of 283 epigenetic-related chemicals and 5 chemotherapeutic drugs. We identify distinct transcription factors that distinguish molecular subtypes of pancreatic cancer, predict numerous chromatin accessibility peaks associated with gene regulatory networks, discover regulatory noncoding mutations with potential as cancer drivers, and reveal the chromatin accessibility signatures associated with drug sensitivity. These results not only provide the chromatin accessibility atlas of pancreatic cancer but also suggest a systematic approach to comprehensively understand the gene regulatory network of pancreatic cancer in order to advance diagnosis and potential personalized medicine applications.

[Effect of recombinant adenovirus Ad-DT-A in targeted therapy for malignant cancer cell lines with loss of IGF2 imprinting].

OBJECTIVE: To explore the feasibility of IGF2 imprinting system in target gene therapy for tumors. METHODS: The mouse H19 enhancer, DMD and promoter H19 were amplified by PCR from mouse genomic DNA and then cloned into the plasmid pDC312. The EGFP and DT-A fragments were amplified by PCR and cloned into the recombinant plasmid, and then the shuttle plasmid were transfected into HEK293 cells together with the adenoviral vector Ad5, namely, Ad-EGFP and Ad-DT-A. Adenovirus hexon gene expression was applied to confirm the presence of adenovirus infections. The effect of the IGF2 imprinting system was tested by fluorescence microscopy. RT-PCR and Western blotting after transfection of the recombinant adenoviral vectors into cancer cells were used to show loss of IGF2 imprinting (LOI) and maintenance of IGF2 imprinting (MOI), respectively. The anti-tumor effect was assessed by MTT and flow cytometry after the HCT-8 (LOI). Human breast cancer cell line MCF-7 (MOI) and human normal gastric epithelial GES-1 (MOI) cell line were transfected with Ad-DT-A in vitro. The anti-tumor effect was detected by injecting the Ad-DT-A in nude mice carrying HCT-8 tumors. RESULTS: The expression of EGFP protein, DT-A mRNA and DT-A protein were seen to be positive only in the HCT-8 tumor cell line. Infection with Ad-DT-A resulted in obviously growth inhibition in HCT-8 cells (75.4 ± 6.4)% compared with that in the control group, and increased the percentage of apoptosis in the HCT-8 cells (20.8 ± 5.9)%. The anti-tumor effect was further confirmed by injecting the recombinant adenoviruses in HCT-8 tumor-bearing nude mice, and the results showed that the Ad-DT-A inhibited the tumor growth, with on inhibition rate of 36.4%. CONCLUSIONS: The recombinant adenoviruses carrying IGF2 imprinting system and DT-A gene have been successfully constructed, while Ad-DT-A can effectively kill the tumor cells showing loss of IGF2 imprinting. It might play an important role in future target gene therapy against malignant tumors based on loss of IGF2 imprinting.

AGEs promote calcification of HASMCs by mediating Pi3k/AKT-GSK3ß signaling.

This study aimed to investigate the effects of advanced glycation end products (AGEs) on the calcification of human arterial smooth muscle cells (HASMCs) and to explore whether AGEs can promote the calcification of HASMCs by activating the phosphoinositide 3-kinase (PI3K)/AKT-glycogen synthase kinase 3 beta (GSK3-ß) axis. Cultured HASMCs were divided into five groups: blank control group, dimethyl sulfoxide (vehicle) group, AGEs group, LY294002 (AKT inhibitor) group, and TWS119 (GSK3-ß inhibitor) group. Cells were pretreated with either vehicle, LY294002, or TWS119 for 2 hours followed by incubation with AGEs (25 µg/mL) for 5 days, and the expression levels of proteins in each group were analyzed by western blotting. AGE treatment promoted HASMC calcification, which coincided with increased expression of p-AKT and p-GSK3-ß (serine 9). Also, AGEs upregulated the expression of osteoprotegerin and bone morphogenetic protein, and these effects were suppressed by LY294002 but enhanced by TWS119. In conclusion, AGEs promote calcification of HASMCs, and this effect is ameliorated by inhibition of AKT activity but potentiated by inhibition of GSK3-ß activity. Hence, AGEs trigger HASMC calcification by regulating PI3K/AKT-GSK3-ß signaling.