Secretion Research Articles

Research progress of role of inflammasome in spinal cord functional recovery after spinal cord injury

Spinal cord injury is a severe central nervous system damage. The inflammatory response plays a critical role in the secondary injury of spinal cord injury. Inflammasomes which promote the processing, maturation and secretion of interleukin (IL)-1β and IL-18 by regulating the activation of caspase-1 consequentially trigger and aggravate the inflammatory response after spinal cord injury. Targeting upstream and downstream pathways of inflammasomes to interfere with inflammatory response can significantly promote functional repair after spinal cord injury. This review will focus on the inflammasome types, the mode of activation and the treatment strategies of inflammasomes after spinal cord injury, so as to provide reference for researches on inflammation and spinal injury repair. Key words: Spinal cord injuries; Inflammation; Caspase-1

Research progress and diagnostic value of exosome microRNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, and its mortality ranks fourth in global malignant tumors. Early diagnosis of HCC has an important impact on the survival rate of patients. Exosomal microRNA (miRNA) is closely related to the occurrence and development of HCC. It can be secreted and transferred to recipient cells through the corresponding target genes, and play a role of regulating cancer progression. Exosomal miRNAs have great differences in the expression of HCC patients and in vitro cell lines, and it has the advantages of high content, specificity and stability relative to circulating miRNAs. It not only can better distinguish between HCC and healthy patients, but also can be further differentiated from hepatitis or cirrhosis, and it also has certain value in the diagnosis of recurrent HCC. Key words: Carcinoma, hepatocellular; Exosomes; microRNAs

Role of adiponectin in retinopathy of prematurity

Retinopathy of prematurity (ROP) is a disease which the retinal vascular system is not mature at birth, leading to cessation of development and abnormal proliferation of blood vessels, in a relatively high oxygen environment.Adiponectin (APN) is an endogenous bioactive protein secreted by adipocytes.It has functions of regulating Glucose and lipid metabolism, inhibiting atherosclerosis and protecting the cardiovascular system.APN can inhibit angiogenesis which may be involved in the occurrence and development of ROP in recent research.APN may be regulating the serum level of tumor necrosis factor α (TNF-α), insulin-like growth factor 1 (IGF-1), and vascular endothelial growth factor (VEGF) A to prevent the development of ROP.The expression of APN is also affected by fibroblast growth factor 21 (FGF-21) and long-chain polyunsaturated fatty acids (ω-3 LCPUFAs) at the same time.Understanding the role of APN in ROP can provide new ideas for further study of the pathogenesis and prevention and treatment of ROP. Key words: Retinopathy of prematurity; Adiponectin; Neovascularization; Review

Increased Angiopietin-2 expression, enhanced proliferation, migration and formation of blood vessels in hemangioma-derived stem cells

Objective To investigate the effect of Angiopoietin-2 (Ang2) up-regulation on the biological function of hemangioma stem cells (HemSCs). Methods HemSCs was isolated and purified by enzyme digestion and immunomagnetic beads sorting. HemSCs was stably up-regulated by Ang2 by lentiviral transfection. The expression level of secreted Ang2 and vascular endothelial growth factor (VEGF) in HemSCs up-regulated by Ang2 was detected by enzyme linked immunosorbent assay (ELISA) method. EDU method The Trangswell method was used to observe the proliferation and migration ability of HemSCs cells up-regulated by Ang2. The tumor formation of nude mice was observed by single cell suspension. The tumorigenic ability of HemSCs was up-regulated by Ang2. The expression of key target proteins in phosphatidylinositol 3 kinase (PI3K)/serine-threonine protein kinase (Akt) cell signaling pathway was detected by Western blotting. Results The proliferation of HemSCs cells up-regulated by Ang2 was enhanced (blank group: 117.000±3.786, control group: 126.000±3.464, experimental group: 179.667±2.603, P<0.01), and migration ability was enhanced (blank group: 102.667±2.028, control group: 108.000±2.646, experimental group: 308.667±2.603, P<0.01); Ang2 in HemSCs Ang2↑ group (blank group: 60.103±0.361, control group: 69.343±0.526, experimental group: 1 962.440±43.205, P<0.01), VEGF (The blank group: 92.667±3.480, the control group: 91.000±1.523, the experimental group: 455.000±15.100, P<0.01) the expression of secreted protein was up-regulated; PI3K-Akt signaling pathway-related protein: Akt1 (blank group: 0.612±0.163, control group: 0.624±0.163, experiment Group: 0. 907±0.162, P<0.01), PI3K (blank group: 0.624±0.163, control group: 0.474±0.163, experimental group: 0.766±0.162, P<0.01), PI3KR5 (blank group: 0.505±0.163, control group: 0.405±0.163, Experimental group: 0.890±0.162, P<0.01), PAkt (blank group: 0.549±0.163, control group: 0.644±0.163, experimental group: 0.684±0.162, P<0.01), p38 (blank group: 0.618±0.163, control Group: 0.759±0.163, experimental group: 0. 947±0.162, P<0.01) Enhanced expression in HemSCs Ang2↑ group. Conclusion Upregulation of Ang2 can enhanced HemSCs proliferation, migration, in vivo angiogenesis; through PI3K-Akt signaling pathway Development has an impact. Key words: Hemangioma; Stem cell; Ang-Tie2 lentivirus; Signaling pathway

Hypoxia inducible factor-2α knockout macrophages alleviate the renal ischemia-reperfusion injury via regulating the expression of inflammatory cytokines

Objective To investigate the protective effect of hypoxia inducible factor-2α (HIF-2α) knockout macrophages to renal ischemia-reperfusion injury through regulating the expression of inflammatory cytokines. Methods The HIF-2α+ /+ and HIF-2α-/-mice were randomly divided into the sham operation group (n=20) and renal IR group (n=20) . The survival time of mice was observed. Mice were sacrificed 24 h after renal reperfusion to obtain blood and renal samples. The expressions of blood urea nitrogen (BUN), creatinine (Cr) in serum and the inflammatory cytokines encoding interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in serum as well as renal tissues were measured. In addition, the histomorphological changes were analyzed via hematoxylin and eosin (HE) staining. Macrophages derived from bone marrow of HIF-2α+ /+ and HIF-2α-/- mice were divided into normoxic group and hypoxic group. The levels in cell culture supernatants of IL-1β, IL-6, IL-10, TNF-α and IFN-γ were examined by enzyme linked immunosorbent assay (ELISA). Results Compared with HIF-2α+ /+ + IR group, mice in HIF-2α-/-+ IR group had significantly longer survival time (P 0.05) . Compared with HIF-2α+ /+ + hypoxic group, bone marrow-derived macrophages (BMDMs) obtained from HIF-2α-/-mice under hypoxic had significantly higher levels of TNF-α and IL-6 (t=12.196, 8.498, P 0.05) . Conclusion Knockout of HIF-2α in macrophages can reduce the secretion of proinflammatory cytokines and increase anti-inflammatory cytokines to protect against renal ischemia-reperfusion injury. Key words: Hypoxia inducible factor-2α; Macrophage; Kidney; Ischemia-reperfusion injury.

Role of leukemia inhibitory factor in tumorigenesis and development

Leukemia inhibitory factor (LIF) is a multifunctional secretory cytokine that plays a role in different tumor tissues and cells through janus kinase/signal transducer and activator of transcription 3, phosphatidylinositol 3-kinase, mitogen-activated protein kinase signaling pathways. LIF is highly expressed in colo-rectal cancer, breast cancer, malignant melanoma, nasopharyngeal carcinoma and other malignant tumors. High expression of LIF can promote the development of cancer, increase the ability of tumor invasion and migration, reduce the sensitivity of radiotherapy and chemotherapy, and lead to poor prognosis. Blocking the LIF signaling pathway can inhibit tumor progression, and LIF is expected to become a new target for tumor therapy. Key words: Neoplasms; Leukemia inhibitory factor; STAT3 transcription factor

The influence of tumor heterogeneity on sensitivity of EGFR-mutant lung adenocarcinoma cells to EGFR-TKIs

Background: Studies have shown that extensive genetic or spatial heterogeneity is present within tumors. The present study explored the influence of heterogeneous cells in the tumor microenvironment (TME) on the sensitivity of EGFR-mutant lung adenocarcinoma cells to EGFR-TKIs and further investigated associated molecular mechanisms. Methods: Tumor heterogeneity was simulated using transwell co-culture technique with H1975, A549 or MRC-5 cells grown in the upper chambers and PC-9 cells cultured in the bottom chamber. Each co-culture system was grouped based on different proportions of cells in the upper and lower chambers (from 1% to 300%), and each group was subdivided into erlotinib treatment group (erlotinib+) and erlotinib non-treatment group (erlotinib−). The viability of PC-9 cells was analyzed by CCK-8; HGF, IGF-1 and TGF-α were determined by ELISA; MET amplification was detected by qRT-PCR, and the relevant proteins were detected by Western blot. Results: The viability of PC-9 cells increased with increased proportion of A549/PC-9 or MRC-5/PC-9 cells from 1% to 300%. HGF increased with increased proportion of H1975 cells from 1% to 300%. In all three co-culture systems, TGF-α production in the erlotinib+ subgroup was significantly lower than that in erlotinib- subgroup, and phosphorylated AKT protein showed an ascending tendency with the increased proportion of upper chamber cells relative to PC-9 cells from 1% to 300%. H1975 cells could induce MET amplification of PC-9 cells. MRC5 cells inhibited MET amplification. Conclusions: Tumor heterogeneity partially accounts for the resistance of EGFR-mutant lung adenocarcinoma cells to EGFR-TKIs. The possible mechanisms may be related to AKT signaling pathways activated by growth factors, which are secreted by heterogeneous cells in the TME under the pressure of EGFR-TKIs.

Ultrastructure and Development of the Olfactory Organ in Indigenous Pelophylax Ridibundus (Amphibia, Rana)

Two olfactory placodes were formed in early embryonic stages. The olfactory epithelia contain receptor, supporting and basal cells. Receptor cells are represented by elongated ciliated cells or microvillated cells, most of the supporting cells are ciliated and some of them are secretory cells. The olfactory placode developed into a principal cavity that differentiated into three chambers as ciliated supporting cells, secretory supporting cells and abundance of ciliated receptor cells and microvillated cells. We observed a tiny projections of small secretory supporting cells of the principle cavity, arranged in row, known as Bowman’s glands to detect odorants in the air, together with the surrounding supporting cells are presumply responsible for mucus-coating the epithelium of the principle cavity.

Diverse inhibition of forkhead box O1 activity by linoleic acid isomers - potential role in lipid metabolism in HepG2 cells and livers of C57BL/6J mice.

Conjugated dienes of linoleic acid (CLA) are constitutional and geometric isomers of linoleic acid that are commonly used as dietary supplements during body mass reduction. Their role in the reduction of lipid deposits in liver tissue is not unequivocal. CLA contain an equimolar mixture of two isomers of linoleic acid: trans-10,cis-12 CLA and cis-9,trans-11. Only one isomer - trans-10,cis-12 CLA exhibits fat-reducing properties, cis-9,trans-11 CLA does not. The main goal of this study was to determine if CLA isomers affect the activation of forkhead box O1 (FoxO1) in liver cells and tissue. FoxO1 is a protein that plays a crucial role in regulation of lipid and carbohydrates metabolism. In vitro and in vivo models of our study were HepG2 cells and C57BL/6J mice. Methods used in the study were qPCR - quantification of FoxO1 gene expression, Western blot - posttranslational phosphorylation of FoxO1, Oil Red O (ORO) - lipid staining and ELISA - quantification of apoB100. In both models trans-10,cis-12 CLA diminished FoxO1 gene expression: decrease by 44.1 ± 20.9% SD in the cells and 65.4 ± 29.8% SD in mice. The lowest accumulation of lipids (drop of 37.2 ± 1.7% SD) and the highest increase of apoB100 protein (74 ± 12.8% SD) were detected in the medium of cells cultured with trans-10,cis-12 CLA. Both isomers of linoleic acid have different effects on lipid metabolism. Isomer c9,t11 CLA accelerates lipogenesis, whereas isomer t10,c12 CLA activates secretion of lipids in HepG2 cells. In contrast to the in vitro study, unfortunately this pro-health property of t10,c12 CLA was not confirmed in the in vivo model. This casts a shadow on CLA dietary supplements that are commonly used among people with type 2 diabetes, NAFLD (non-alcoholic liver disease) or a metabolic syndrome in order to lose weight.

The expression of the renin-angiotensin-aldosterone system in the skin and its effects on skin physiology and pathophysiology.

The local renin-angiotensin-aldosterone system (RAAS) is fully expressed in the human skin at the mRNA and protein level. Local RAAS is known to play a regulatory function in epidermal proliferation, wound healing, scarring, cutaneous heating adaptation, and aging. There are also some indications of its role in the regulation of hair growth and sebum secretion. Impaired wound healing, skin diseases associated with diabetes, cancer development, psoriasis, and scleroderma may be related to changes in skin RAAS activity. Extensive research has shown that RAAS-modulating drugs can affect the skin when applied orally or topically, creating new therapeutic approaches against dermatological diseases.

T cell immunoglobulin and mucin domain-containing protein 3 inhibits interleukin-12 secretion by CD14+ monocytes from patients with psoriasis vulgaris

Objective To assess the role of T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) in regulation of interleukin (IL) -12 secretion by CD14+ peripheral blood monocytes from patients with psoriasis vulgaris. Methods From November 2017 to March 2018, a total of 47 patients with psoriasis vulgaris (psoriasis group) and 19 healthy volunteers (control group) were enrolled from Shanxi Provincial People′s Hospital. Peripheral blood mononuclear cells (PBMC) were isolated, and stimulated with Toll-like receptor (TLR) ligands. TIM-3 expression and IL-12 secretion by CD14+ monocytes were measured by flow cytometry. After blockade of TIM-3 pathway by anti-TIM-3 neutralizing antibody, changes in the downstream signaling pathway molecules in and IL-12 secretion by CD14+ monocytes were investigated. Two independent samples t-test was used for comparison between two groups, and Pearson correlation test for correlation analysis. Results Under the unstimulated condition, the level of IL-12 secreted by CD14+ monocytes was very low, and the proportion of CD14+ TIM-3+ cells was significantly higher in the psoriasis group (12.20% ± 2.83%) than in the control group (9.91% ± 1.77%, t = 3.270, P = 0.001 7) . After the stimulation with TLR ligands, the proportion of CD14+ IL-12+ cells was significantly lower in the psoriasis group (13.49% ± 2.80%) than in the control group (28.97% ± 8.97%, t = 10.71, P < 0.000 1) , but the proportion of CD14+TIM-3+ cells was still higher in the psoriasis group (6.80% ± 1.11%) than in the control group (4.85% ± 1.37%, t = 6.064, P < 0.000 1) . The proportion of CD14+TIM-3+ cells was negatively correlated with that of CD14+ IL-12+ cells in both the control group and psoriasis group (r = -0.473, -0.371 respectively, both P < 0.05) . The TIM-3 pathway blockade could induce the decrease of suppressor of cytokine signaling 1 in CD14+ monocytes, increase the phosphorylation of signaling transducers and activators of transcription 1, and promote IL-12 secretion by CD14+ monocytes induced by keratinocytes isolated from psoriatic skin lesions. Conclusion TIM-3 plays a crucial role in the negative regulation of CD14+ monocyte-induced innate immune response in psoriasis. Key words: Psoriasis; Monocytes; Interleukin-12; Antigens, CD14; T cell immunoglobulin and mucin domain-containing protein 3

The clinical expression and significance of inhibitory receptor TIGIT gene on peripheral NK cells in rheumatoid arthritis

Objective To investigate the expression of inhibitory receptor TIGIT gene in peripheral NK cells of patients with rheumatoid arthritis (RA) and its clinical significance. Methods A case control study was conducted of 58 RA patients(30 patients with active RA disease, 28 patients with remission of RA) and 22 healthy controls (HC) in the department of rheumatology and immunology from Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine during December 2018 to June 2019, the related clinical data were collected. Flow cytometry was used to compare the expression of TIGIT gene on peripheral NK cells. The IFN-γ secretion level of cytokines in peripheral blood was detected by ELISA, and analyzed the correlations between TIGIT gene and disease activity and IFN-γ level. T-test or non-parametric test was used for comparison between the two groups, and Pearson correlation analysis was used for correlation between the two variables. Results Compared with HC group, the number of NK cells in RA disease group was reduced, which was (13.88±4.56) ×107 cells/L in RA disease group and (25.69± 2.48) ×107 cells/L in HC group (t=-2.036, P=0.041). The percentage of TIGIT gene expression in peripheral blood NK cells was not statistically different between RA disease group (39.73±9.37)% and HC group (45.64±9.91)% (t=-1.241, P=0.218). However, the average fluorescence intensity (MFI) of TIGIT gene expression was decreased, which was (7.21±2.03) in RA group and (9.01±3.29) in HC group (t=-2.947, P=0.004).MFI of TIGIT gene in NK cells of the disease active subgroup was (6.72±2.01), lower than that of the disease remission subgroup (8.75±2.64), (t=-3.316, P=0.002), and MFI of TIGIT gene in NK cells of the disease active subgroup was negatively correlated with DAS28 score (r2=0.649 6, P<0.000 1).The secretion level of IFN-γ cytokine in the RA disease group was (67.13±14.84) pg/ml, higher than that in the HC group (57.21±14.23) pg/ml (t=2.757, P=0.017), and the secretion level of IFN-γ cytokine in the disease active subgroup was negatively correlated with the MFI of TIGIT gene on NK cells (r2=0.662 2, P<0.000 1). Experimental results of peripheral blood mononuclear cell stimulation in the RA disease activity subgroup showed that the secretion level of cytokines IFN-γ was reduced after stimulation compared with that before stimulation (t=11.38, P<0.000 1). Conclusion The abnormal expression of TIGIT gene on peripheral NK cells are observed in patients with RA, which correlate with disease activity and IFN-γ secretion level. Key words: Arthritis, rheumatoid; Receptors, immunologic; Killer cells, natural; Interferon-gamma

Research progress on the functions of exosomes in colorectal cancer

Exosomes are a class of extracellular vesicles that secreted by a variety of cells, with the length of 40-100 nm and a lipid bilayer membrane structure. They are often observed in multiple body fluids and are important mediators in intercellular communication. Several researches demonstrated that exosomes are closely linked to the development, invasion, metastasis, and drug resistance of colorectal cancer (CRC). In this review, the role of CRC-derived exosomes in the pathogenesis, diagnosis, prognosis and treatment of CRC were briefly summarized to provide a strategy for new therapeutic targets in CRC. Key words: Colorectal neoplasms; Exosomes; Biomarkers, tumor

Influence of insulin on growth hormone secretion, level and growth hormone signalling.

Growth hormone (GH), as a vital hormone, has to experience a series of processes to fulfill its function including secretion, entering the circulation to reach target tissues (pre-receptor process), binding on the GH receptor (GHR) and triggering signaling inside cells (post-GHR process). Insulin can directly or indirectly influence part of these processes. GH secretion from pituitary somatotropes is regulated by GH-releasing hormone (GHRH) and somatostatin (SS) from hypothalamus. Insulin may exert positive or negative effects on the neurons expressing GHRH and SS and somatotropes under healthy and pathological conditions including obesity and diabetes. Glucose and lipid levels in circulation and dietary habits may influence the effect of insulin on GH secretion. Insulin may also affect GHR sensitivity and the level of insulin-like growth factor 1 (IGF-1), thus influence the level of GH. The GH signaling is also important for GH to play its role. GH signaling involves GHR/JAK2/STATs, GHR/JAK2/SHC/MAPK and GH/insulin receptor substrate (IRS)/PI3K/Akt pathways. These pathways may be shared by insulin, which is the basis for the interaction between insulin and GH, and insulin may attenuate or facilitate the GH signal by influencing molecules in the pathways. Many factors are related to the effect of insulin, among them the most important ones are duration of action and amount of insulin. The tendency of insulin-reduced GH signaling becomes obvious with increased dose and acting time of insulin. The participation of suppressor of cytokine signaling (SOCS), the interaction between JAK2 and IRS, and GHR sensitivity should also be considered when discovering GH signal. The involvement of SS in response to insulin is not clear yet. The details of how GH secretion, level and signaling change in response to time and dose of insulin treatment warrant further studies.

Changes of different subtypes of adiponectin in epicardial fat in patients with coronary heart disease

Objective To study the difference of the secretion and synthesis of adiponectin in different parts of adipose tissue in patients with coronary heart disease (CHD). Methods The serum, epicardial adipose tissue (EAT) and subcutaneous adipose tissue (SAT) in over 50-years old male patients with CHD or valvular heart disease as control group. The patients with CHD were excluded by coronary angiography in control group. Serum adiponectin concentrations were examined in CHD group and control group by enzyme linked immunosorbent assay (ELISA). Serum adiponectin types were classified in accordance with the molecular weight of high-molecular-weight (HMW), medium molecular weight (MMW) and low molecular weight (LMW) in CHD group and non-CHD group by gel filtration chromatography. Real-time PCR was used to detect the expression of adiponectin mRNA in epicardial adipose cells and subcutaneous adipose cells. The levels of HMW MMW LMW adiponectin in adipose cells were determined by non-hearting and non-reducing sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE). Results As compared with non-CHD group, the concentration of serum HMW in CHD group was significantly reduced [(0.55±0.18) mg/L vs. (0.31±0.12) mg/L, t=3.472, P 0.05; LMW: (0.48±0.22) mg/L vs. (0.53±0.20) mg/L, t=1.712, P>0.05]. The expression of adiponectin mRNA in CAD epicardial group was significnatly downregulated when compared with autologous subcutaneous group (0.810±0.101 vs. 1.102±0.135, t=3.351, P<0.01) and control epicardial group (0.810±0.101 vs. 1.008±0.146, t=3.363, P<0.01). The proteomics revealed that the HMW content in CHD group decreased significantly as compared with non-CHD epicardial group and subcutaneous tissue group, and the rest two types of adiponectin showed no statistically significant differences. Conclusion The low expression of adiponectin in patients with CHD is located in the EAT and mainly decreased as the form of HMW adiponectin. Key words: Adiponectin; Epicardial adipose tissue; Coronary artery disease

Correlation study of Secreted Frizzled-related proteins 2 and β-catenin with colorectal carcinogenesis

Correlation study of Secreted Frizzled-related proteins 2 and β-catenin with colorectal carcinogenesis

Autophagy in cancer associated fibroblasts promotes lung adenocarcinoma cells migration and invasion

Objective Autophagy is a process by which cellular material is delivered to lysosomes for degradation, providing energy and macromolecular precursors. Cancer-associated fibroblasts (CAFs) have an important role in reprogramming the tumor microenvironment, and exhibit enhanced migratory capacity through autocrine and paracrine. This study aims to explore the possible effects of CAFs autophagy on lung adenocarcinoma cells migration and invasion. Methods Lung adenocarcinoma cell line A549 was co-cultured with or without CAFs via Transwell and Matrige lassay under the same culture condition, the effects of CAFs autophagy on the migration and invasion of A549 were observed. Results We demonstrate autophagy activated CAFs have great ability than CAFs to enhance the migration [(122.7±17.6) cells/cm2 vs. (269.3±72.7) cells/cm2] and invasion [(124.3±19.6) cells/cm2 vs. (280.0±32.1) cells/cm2] of lung adenocarcinoma (LUAD) cell line (F=18.640, 80.630, P<0.05). Interleukin 6 [(545.5±28.2) ng/L vs. (865.4±70.9) ng/L] and interleukin 8 [(374.2±62.2) ng/L vs. (672.4±24.2) ng/L] were highly expressed in the autophagy activated CAFs conditioned media (t=7.261, 7.738, P<0.05). Conclusion Our results establish an oncogenic function for secretory autophagy in CAFs that promote LUAD migration and invasion. Key words: Lung adenocarcinoma; Cancer-associated fibroblasts; Autophagy; Migration and invasion

Senescent HUVECs-secreted exosomes trigger endothelial barrier dysfunction in young endothelial cells.

Accumulation of senescent endothelial cells can cause endothelium dysfunction which eventually leads to age-related vascular disorders. The senescent-associated secretory phenotype (SASP) cells secrete a plethora of soluble factors that negatively influence the surrounding tissue microenvironment. The present study sought to investigate the effects of exosomes, which are nano-sized extracellular vesicles known for intercellular communications secreted by SASP cells on young endothelial cells. Exosomes were isolated from the condition media of senescent human umbilical vein endothelial cells (HUVECs) and then confirmed by the detection of exosome specific CD63 and CD9 expressions, electron microscopy and acetylcholinesterase assay. The purified exosomes were used to treat young HUVECs. Exposure to exosomes repressed the expression of adherens junction proteins including vascular endothelial (VE)-cadherin and beta-catenin, decreased cell growth kinetics and impaired endothelial migration potential of young endothelial cells. These findings suggest that senescent HUVECs-secreted exosomes could disrupt barrier integrity that underpins endothelial barrier dysfunction in healthy young endothelial cells.

Eukaryotic expression and serodiagnostic potential of HIV-1 p24 antigen

Objective To express HIV-1 capsid p24 antigen in an eukaryotic expression system and to evaluate its antigenicity and potential in the early diagnosis of HIV. Methods The full-length gene of HIV-1 p24 and the signal peptide DRVI gene were amplified by PCR. The signal peptide DRVI preceding the p24 gene was introduced using fusion PCR, and cloned into vector pDRVI1.0. Two recombinant plasmids pDRVI-p24 and pDRVI-p24s were constructed and transfected into 293F cells. Expression and secretion of p24 protein were detected by SDS-PAGE, Ni-NTA column chromatography and molecular sieve were used to purify p24s protein. The purified protein was identified by Western blot and indirect ELISA using human/mouse HIV-1-positive serum samples. Results The eukaryotic expression system for HIV-1 p24 antigen was successfully established with high efficiency. The target protein of interest with the signal peptide DRVI was obviously detected in the supernatants of cell culture. The recombinant protein had good specificity and sensitivity based on the results of serological tests using serum samples of five HIV-1-positive and five HIV-negative mice, 30 HIV-1-positive patients and 50 HIV-1-negative healthy individuals. Conclusions The eukaryotic expression system for HIV-1 p24 antigen was successfully established. The purified HIV-1 p24s antigen had good antigenicity. An indirect ELISA assay with good specificity and sensitivity for the detection of HIV-1 was preliminarily constructed and showed great potential for application. Key words: HIV-1; p24 core antigen; Eukaryotic expression; Serological diagnosis

Research progress of HMGB1 gene polymorphism related to disease

High mobility group protein B1 (HMGB1) is encoded by HMGB1 gene and is a highly conserved non-histone chromosomal binding protein widely present in the nucleus. It plays an important role in DNA replication and repair of eukaryotic cells. As a delayed inflammatory mediator, HMGB1 secreted or released extracellularly mediates inflammatory response in sepsis, autoimmune diseases, malignant tumors, liver-related diseases, and so on. In recent years, the studies of HMGB1 gene polymorphism have provided a theoretical basis for further clarifying the pathogenesis of diseases. These studies provided early predictions of disease susceptibility for early intervention and provided the basis for precise prevention and treatment of diseases. In this paper, the correlation between HMGB1 and clinical disease susceptibility and prognosis was reviewed. Key words: HMGB1 protein; HMGB1 gene; Single nucleotide polymorphisms; Sepsis; Malignant tumor