Krüppel-Like Factor 2 Is a Gastric Cancer Suppressor and Prognostic Biomarker.

Gastric cancer (GC) is a common digestive tract tumor. Due to its complex pathogenesis, current diagnostic and therapeutic effects remain unsatisfactory. Studies have shown that KLF2, as a tumor suppressor, is downregulated in many human cancers, but its relationship and role with GC remain unclear. In the present study, KLF2 mRNA levels were significantly lower in GC compared to adjacent normal tissues, as analyzed by bioinformatics and RT-qPCR, and correlated with gene mutations. Tissue microarrays combined with immunohistochemical techniques showed downregulation of KLF2 protein expression in GC tissue, which was negatively correlated with patient age, T stage, and overall survival. Further functional experiments showed that knockdown of KLF2 significantly promoted the growth, proliferation, migration, and invasion of HGC-27 and AGS GC cells. In conclusion, low KLF2 expression in GC is associated with poor patient prognosis and contributes to the malignant biological behavior of GC cells. Therefore, KLF2 may serve as a prognostic biomarker and therapeutic target in GC.

Biphenylene network as sodium ion battery anode material.

Sodium ion batteries possess several advantages for large-scale energy storage, such as low cost and enhanced safety. However, graphite or other anode materials are not satisfactory because the large radius of Na+ hinders their embedding and removal in the charge and discharge processes. Recently, a biphenylene network (BPN), a two-dimensional (2D) carbon allotrope, has been synthesized. In this paper, we reveal the potential possibility of BPN as a Na storage material. The theoretical results indicate the advantages of BPN as a sodium battery anode. The maximum specific capacity (413 mA h g-1) is larger than that of the graphite-Li system (372 mA h g-1). With low Na+ diffusion barrier (<0.6 eV) and small volume expansion in the charging process (∼26%), BPN presents superiority to the graphite-Na system. Our findings show new insights into Na storage in BPN and provide guidance for the use of a BPN anode in sodium ion batteries.

Selective CO2 reduction on topological Chern magnet TbMn6Sn6.

As a new type of topological magnet, TbMn6Sn6 has a planar Mn kagome lattice with out-of-plane magnetic moments. Previous studies have found spin-polarized Chern gapped Dirac fermions in TbMn6Sn6, which are advantageous to topological catalysis. In this study, we theoretically demonstrate that the TbMn6Sn6 (001) surface is favorable for CO2 reduction. The stability of different surface types is investigated, and then the reaction paths of CO2 reduction on the surfaces are revealed to prove that the product is selective. This work reveals the effect of magnetic topological materials on CO2 reduction.

CO2 reduction on single-atom Ir catalysts with chemical functionalization.

As promising catalytic systems, single-atom catalysts (SACs) demonstrate improved catalytic performance for electrochemical reactions. However, the pinning of metal atoms on surfaces usually depends on the adsorption on defects. In this study, defect-free functionalization by attaching IrX3 (X = F or Cl) complexes on the MoS2 monolayer is theoretically demonstrated. The ligand-based method offers a damage-free route for stabilizing SACs on 2D materials. We demonstrate the CO2 reduction process on MoS2-IrX3 with a small change in free energy and a low onset potential. The d6 shell of Ir acts as a molecular joint with universal orbital orientations, which benefits the adsorption of different reaction intermediates. This study shows the superiority of defect-free functionalization of 2D materials using SAC-ligand complexes.

[Absorption and Three Dimensional Fluorescence Spectra of CDOM in the Water of the Taibaishan Nature Reserve].

It is very important to understand water ecology and the carbon cycle process by studying the composition, source, spectral characteristics, and influence factors of chromophoric dissolved organic matter (CDOM). The optical characteristics, composition, and source of CDOM in 71 water samples were collected from the lakes and four rivers of the Taibaishan Nature Reserve in the summer of 2019. The rivers included the Bawang, Heihe, Shitou, and Xushui Rivers. They were analyzed by UV-Vis spectral and three-dimensional fluorescence spectroscopy, combined with a parallel factor analysis model and redundant analysis. The results showed that CDOM in the water of the Taibaishan Nature Reserve contained two types of four fluorescent components, in which the humus-like components C1 and C2 were the main components of CDOM. The relative contribution of C1 and C2 to the rivers was 82%-96%, which was significantly larger than the lakes. All fluorescence indexes (FI) were larger than 1.8, the index of recent autochthonous contribution (BIX), and the index of freshness (ß:α) were all approximately 0.6. The humification indexes (HIX) of the rivers were significantly larger than those of the lakes (P<0.01). The DOM in the rivers was mainly from the forest soil of the Nature Reserve, and the water quality of the lakes was affected by tourists to some extent. The results of the redundant analysis show that the CDOM spectral characteristic parameters were significantly influenced by EC for the lakes (P<0.05) and by EC, DTN, and DOC for the rivers (P<0.01).

Mesenchymal stem cells attenuated PLGA-induced inflammatory responses by inhibiting host DC maturation and function.

The poly lactic-co-glycolic acid (PLGA) bio-scaffold is a biodegradable scaffold commonly used for tissue repair. However, implanted PLGA scaffolds usually cause serious inflammatory responses around grafts. To improve PLGA scaffold-based tissue repair, it is important to control the PLGA-mediated inflammatory responses. Recent evidence indicated that PLGA induce dendritic cell (DC) maturation in vitro, which may initiate host immune responses. In the present study, we explored the modulatory effects of mesenchymal stem cells (MSC) on PLGA-induced DCs (PLGA-DC). We found that mouse MSCs inhibited PLGA-DC dendrite formation, as well as co-stimulatory molecule and pro-inflammatory factor expression. Functionally, MSC-educated PLGA-DCs promoted Th2 and regulatory T cell differentiation but suppressed Th1 and Th17 cell differentiation. Mechanistically, we determined that PLGA elicited DC maturation via inducing phosphorylation of p38/MAPK and ERK/MAPK pathway proteins in DCs. Moreover, MSCs suppressed PLGA-DCs by partially inactivating those pathways. Most importantly, we found that the MSCs were capable of suppressing DC maturation and immune function in vivo. Also, the proportion of mature DCs in the mice that received MSC-PLGA constructs greatly decreased compared with that of their PLGA-film implantation counterparts. Additionally, MSCs co-delivery increased regulatory T and Th2 cells but decreased the Th1 and Th17 cell numbers in the host spleens. Histological analysis showed that MSCs alleviated the inflammatory responses around the grafted PLGA scaffolds. In summary, our findings reveal a novel function for MSCs in suppressing PLGA-induced host inflammatory response and suggest that DCs are a new cellular target in improving PLGA scaffold-based tissue repair.

[Influence of donor mouse age on the establishment of murine acute graft versus host disease model after allogenic hematopoietic stem cell transplantation].

This study was purposed to elucidate the influence of donor mouse age on the establishment of murine acute graft versus host disease (aGVHD) model after allogenic hematopoietic stem cell transplantation. The male mice with 2-week-old, 10-week-old and 18-week-old mice (BALB/cH-2Kb) were taken as donors. The 8-week-old mice (BALB/c, H-2Kd) were selected as recipients. Each group animals were irradiated with 7.5 Gy (60)Co for total body, the recipient mice were injected intravenously with 1 × 107 bone marrow cells and 1 × 107 spleenoctyes from various donors in 4-5 hours after irradiation. Mouse transplant characteristics and survival were observed every day. The white blood cell number in peripheral blood of each group were counted at day 5, 10, 15, 20, 25 and 30 after transplantation. Furthermore, the pathological damage in the liver, spleen, lung and intestines were evaluated by sectioning and in situ hematoxylin-eosin (HE) staining. The results showed that compared with the 2-week-old and 10-week-old donor groups, mice received bone marrow (BM) cells and splenocytes from 18-week-old mice showed higher incidence of aGVHD, lower clinical GVHD scores and suffered from diarrhea, ruffled hair, a hunched posture, and diminished body weight. In contrast, mice received BM cells and splenocytes from 2-week-old donor mice indicated attenuated GVHD symptoms and survived longer. The histo-pathological analysis in 18-week-old donor group demonstrated the most serious pathological damage in the liver, spleen, lung and intestines. It is concluded that the donor age has been confired to have an obvious influence on the establishment of murine aGVHD model. This study lay an important foundation for establishing animal models and may be helpful for further study.

[Construction of mouse VCAM-1 expression vector and establishment of stably transfected MSC line C3H10T1/2].

This study was aimed to construct the mouse VCAM-1 expression vector, to establish the stably transfected MSC line and to investigate the effect of VCAM-1-modified mesenchymal stem cells (MSC) on the immunological characteristics of MSC. The cDNA of murine VCAM-1 gene was amplified by RT-PCR from the total RNA isolated from the mouse spleen; then the cDNA was inserted into the retrovirus vector PMSCVmigr-1; the recombinant plasmid was confirmed by restriction endonuclease experiments and sequencing, then designated as PMSCVmigr-1-mVCAM-1; the recombinant plasmid PMSCVmigr-1-mVCAM-1 was transfected into 293 cells by lipofecamin and the supernatant was collected to transfect MSC cell line (C3H10T1/2). Moreover, VCAM-1 expression on MSC was evaluated by FACS. Furthermore, the inhibitory effect of VCAM-1-MSC on lymphocytic transformation was tested by (3)H-TdR incorporation assay. The results indicated that the successful construction of recombinant retroviral expression plasmid of mouse VCAM-1 was confirmed by digesting and sequancing. After transfection of MSC with retroviral supernaptant, the high expression of VCAM-1 on MSC could be detected by flow cytometry. The MSC high expressing VCAM-1 could significantly inhibit the proliferation of Con A-inducing lymphocytes in dose-depentent marrer. It is concluded that recombinant retroviral encoding VCAM-1 (PMSCVmigr-1-mVCAM-1) has been successfully constructed and mouse VCAM-1 has been stably expressed in C3H10T1/2. MSC over-expressing VCAM-1 show more potent immunosuppressive effect on cellular immune reaction in vitro. Our data laid a foundation for the subsequent studying the effect of VCAM-1 transfecting into MSC on immune related disease study.

[Effect of different irradiation doses on the establishment of murine cGVHD model after MHC matched spleen stem cell transplantation].

This study was aimed to investigate the effect of different irradiation doses on the establishment of murine cGVHD model after MHC matched spleen stem cell transplantation. The male mouse BALB/c(H)-2d was totally irradiated with different radiation dose of (60)Co (TBI), then was infused with the same number of splenocytes from MHC matched DBA/2 male mice. After transplantation, the bodyweight, general appearance, hair changes, survival time and pathological damage were observed. The results indicated that compared to the control group (0 Gy) and the 7.0 Gy group, the mice irradiated with 7.5 Gy and 8.0 Gy showed cGVHD symptoms and obvious pathological damage. At the end of experiments (60 d after transplantation), all mice irradiated by 7.5 Gy survived while only 60% animals survived in the 8.0 Gy group. It is concluded that under infusion of 10(8) MHC matched splenocytes per mouse, 7.5 Gy irradiation is appropriate to efficiently establish cGVHD model. This study laid an important foundation for further studying the pathogenesis, biological characteristics, and intervention factors of cGVHD.

[Effect of intercellular adhesion molecule-1 on the migration in vitro of murine mesenchymal stem cells and its related mechanism].

This study was aimed to investigate the effect of intercellular adhesion molecule-1 (ICAM-1) on the migration in vitro of the murine mesenchymal stem cells (MSC) and its related mechanisms. The migration ability of murine MSC (C3H10T1/2), ICAM-1 transfected MSC (C3H10T1/2-MIGR1-ICAM-1) and empty vector-transfected MSC (C3H10T 1/2-MIGR1) were assayed in vitro by using the transwell system. Briefly, the cells were seeded on the membrane with 8 µm aperture and the fetal bovine serum was used as the chemotactic agent to induce MSC migration. The transmigrated cells were stained by crystal purple as well as DAPI for 8 h and 12 h respectively. The absolute cell numbers were counted and the migration rates of MSC were evaluated in each group. To explore the potential mechanisms which control the migration of MSC, the specific chemical inhibitors of MAPK pathway (SB203580, PD98059 and JNK inhibitor II) were added to the transwell system and the alteration of the MSC migration ability were evaluated at 12 h. The results showed that the migration ability at 8 h and 12 h of the ICAM-1-transfected MSC increased. Both absolute cell number and migration rate of MSC were significantly up-regulated by ICAM-1. Furthermore, the promoting effect of ICAM-1 on migration was partially suppressed by the inhibition of JNK/SAPK pathway. The transmigrated cell numbers and the migration rate decreased with the addition of JNK inhibitor II. However, the ICAM-1 promoting migration of MSC was not suppressed by the inhibitors for ERK/MAPK and p38/MAPK pathway did not work in the present study. It is concluded that ICAM-1 can induce mouse MSC migration in vitro, and the promoting effect is partially dependent on the activation of JNK/SAPK pathway.

[Latest research progress on pathogenesis of chronic graft versus host disease and its related problems].

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective method for the treating of malignant diseases of hematopoietic system or non-malignant proliferative diseases, but the occurrence of graft-versus-host disease (GVHD) limits the success rate of hematopoietic stem cell transplantation. Moreover, chronic graft-versus-host disease (cGVHD) is the main factor affecting the long-term survival rate and life quality of recipient after hematopoietic stem cell transplantation. In this article, the latest research progress of the pathogenesis of cGVHD and related problems are reviewed from the thymus, cytokines, T lymphocyte subsets, B lymphocytes and its secreted antibody.

Intercellular adhesion molecule-1 inhibits osteogenic differentiation of mesenchymal stem cells and impairs bio-scaffold-mediated bone regeneration in vivo.

Mesenchymal stem cell (MSC) loaded bio-scaffold transplantation is a promising therapeutic approach for bone regeneration and repair. However, growing evidence shows that pro-inflammatory mediators from injured tissues suppress osteogenic differentiation and impair bone formation. To improve MSC-based bone regeneration, it is important to understand the mechanism of inflammation mediated osteogenic suppression. In the present study, we found that synovial fluid from rheumatoid arthritis patients and pro-inflammatory cytokines including interleukin-1α, interleukin-1ß, and tumor necrosis factor α, stimulated intercellular adhesion molecule-1(ICAM-1) expression and impaired osteogenic differentiation of MSCs. Interestingly, overexpression of ICAM-1 in MSCs using a genetic approach also inhibited osteogenesis. In contrast, ICAM-1 knockdown significantly reversed the osteogenic suppression. In addition, after transplanting a traceable MSC-poly(lactic-co-glycolic acid) construct in rat calvarial defects, we found that ICAM-1 suppressed MSC osteogenic differentiation and matrix mineralization in vivo. Mechanistically, we found that ICAM-1 enhances MSC proliferation but causes stem cell marker loss. Furthermore, overexpression of ICAM-1 stably activated the MAPK and NF-κB pathways but suppressed the PI3K/AKT pathway in MSCs. More importantly, specific inhibition of the ERK/MAPK and NF-κB pathways or activation of the PI3K/AKT pathway partially rescued osteogenic differentiation, while inhibition of the p38/MAPK and PI3K/AKT pathway caused more serious osteogenic suppression. In summary, our findings reveal a novel function of ICAM-1 in osteogenesis and suggest a new molecular target to improve bone regeneration and repair in inflammatory microenvironments.

[ICAM-1 regulates differentiation of MSC to adipocytes via activating MAPK pathway].

This study was aimed to explore the molecular mechanism of the regulatory effects of ICAM-1 on the differentiation of mesenchymal stem cells (MSC) to adipocytes. The murine MSC cell line C3H10T 1/2 was treated with the supernatants contained plasmid MIGR1-ICAM-1 and MIGR1-ICAM-1/MSC (high expression of ICAM-1), the activation of the pathway was detected by Western blot. The ICAM-1 modified MSC and its control cells named MIGR1/MSC were cultured in adipocyte medium with or without the inhibitors of the ERK, P38, and JNK pathway. Oil-red-O staining was used to detect the lipid accumulation, and the expression of C/EBPα and PPARγ in differentiation of MSC to adipocyte were examined by real-time-PCR. The results showed that the overexpression of ICAM-1 stably activated the ERK, P38, and JNK pathway in MSC. Inhibiting of the activation of ERK pathways by chemical inhibitors up-regulated the mRNA expression level of C/EBPα and PPARγ in MIGR1-ICAM-1/MSC while inhibiting of P38 pathway resulted in lower mRNA expression of the transcription factors. Consistent with the mRNA expression, the lipid droplets were getting smaller and number of adipocytes increased when P38 pathway was inhibited, while bigger lipid droplet and increased quantity of adipocytes were identified in MIGR1-ICAM-1/MSC with the addition of ERK pathway inhibitor. It is concluded that ICAM-1 may suppress MSC differentiate into adipocyte via activating ERK pathway, while it can maintain the adipogenesis of MSC though P38 pathway.

[Clinical and pathological analysis of 41 cases of acute leukemia combined with intracranial hemorrhage].

This study was aimed to summarize the clinical and pathological features of patients with acute leukemia combined with intracranial hemorrhage. The clinical and pathological data of 41 adult patients diagnosed as acute leukemia in our hospital from 1953 to 1990 year were analyzed retrospectively. The results showed that there were 35 cases of AML, 6 cases of ALL; 9 cases in clinical hematologic remission, 32 cases in non-remission, 3 cases of AL with hypertension, 2 cases of AL with diabetes, 4 cases of AL with sepsis, 19 cases with WBC ≥ 100×10(9)/L; the pathologic examination showed 4 cases of AL accompanied with disseminated intravascular coagulation, 10 cases with prothrombin time INR ≥ 1.5, 26 cases with multifocal intracranial hemorrhage, 7 cases with single intracranial hemorrhage, 8 cases with diffused spotting intracranial hemorrhage; the examination also showed that 84 hemorrhage foci were found in 41 cases of AL, among them 46 foci located under cerebral cortex, 23 foci in cerebellum, 6 in basal ganglia, 5 foci in pons, 2 foci in thalamus, 2 foci in spinal cord. It is concluded that the intracranial hemorrhage is a major cause resulting in death of AL patients which should be think highly, and the diagnosis and treatment should be conducted through comprehensive analysis.

Intramuscular immunization with a plasmid DNA vaccine encoding prM-E protein from Japanese encephalitis virus: enhanced immunogenicity by co-administration of GM-CSF gene and genetic fusions of prM-E protein and GM-CSF.

OBJECTIVE: To investigate the immune responses elicited by pJME with or without various forms of granulocyte-macrophage colony-stimulating factor (GM-CSF) gene. METHODS: The changes of the T lymphocyte subsets and the levels of Th cell intracellular cytokines IFN-gamma and IL-4 were evaluated by flow cytometric analysis. The cytotoxic T lymphocyte kill activity was assessed by lactate dehydrogenase activity release test. An 80% plaque reduction neutralization test was performed to titrate the neutralization antibody before and after viral challenge. RESULTS: We demonstrated that simultaneous administration of pJME plus plasmid-ecoded GM-CSF (pGM-CSF) activated Th1 immune responses similar to those found by injecting pGM-CSF i.m. into mice 3 days before pJME vaccination, and enhancement of Th2 immunity predominated when the pGM-CSF was injected 3 days after pJME vaccination. Furthermore, the immunization with DNA vaccine encoding precursor membrane envelope/GM-CSF fusion protein was more effective in generating immune responses than that induced by immunization with pJME alone or in combination with pGM-CSF. CONCLUSIONS: These observations support the potential of GM-CSF DNA adjuvant for the Th1/Th2 balance and the enhancement of immune responses by showing that the timing of the administration of pGM-CSF and the application of different forms of GM-CSF gene influence the outcome of the resultant immune responses.

Immunologic analysis induced by DNA vaccine encoding E protein of Beijing-1 strain derived from Japanese encephalitis virus.

OBJECTIVE: We have compared the gene expression and DNA immunization efficacy encoding prME and E proteins of a different strain (JaGAr-01) derived from Japanese encephalitis virus. This study aimed to construct a recombinant encoding E protein of the Beijing-1 strain derived from Japanese encephalitis virus and analyze the humoral, cellular and protective immunity induced by the above recombinant. METHODS: The recombinant pJBE containing E (1,500 bps) gene from the Beijing-1 strain of Japanese encephalitis virus was constructed and then transfected into the HepG2 cell line by liposome fusion. The expression of E (about 53 kD) protein in transfected cells was analyzed by Western blot using a specific anti-JEV-E antibody. BALB/c mice were vaccinated with 3 microg of pJBE by the gene-gun technique. JaGAr-01 and Beijing-1 strains (10(5) PFU/100 microl) of Japanese encephalitis virus were given to BALB/c mice by intraperitoneal injection 3 weeks after double DNA immunization with a lethal virus challenge. BALB/c mice were observed for 21 days after challenge. An 80% plaque reduction neutralization test was performed to titrate the neutralization antibody before and after viral challenge. A lactate dehydrogenase activity release test was used to examine cytotoxic T lymphocyte activity after double DNA immunization. RESULTS: The expression of about 53 kD protein associated with pJBE was determined in transfected HepG2 cells with specific anti-JEV-E antibody. A higher level of neutralization antibodies and the cytotoxicity effect were induced with pJBE immunization using the gene-gun technique, and were similar to those induced with inactivated vaccine derive from the Beijing-1 strain of Japanese encephalitis virus. Balb/c mice immunized with pJBE survived the challenge with the different strains of Japanese encephalitis virus; however, Balb/c mice immunized with inactivated vaccine did not survive the challenge with the JaGAr-01 strain of Japanese encephalitis virus at all. CONCLUSIONS: DNA vaccine containing the E protein gene derived from Japanese encephalitis virus can provide not only better efficacy including humoral and cellular immunity, but also cross-protection against infection with homologous and heterologous Japanese encephalitis virus.