Real-Time analysis of exosome secretion of single cells with single molecule imaging

The exosome-mediated response can promote or restrain the diseases by regulating the intracellular pathways,making the exosome become an effective marker for diagnosis and therapeutic control at the single-cell level.However,real-time analysis is hard to be achieved with traditional approaches because the exosomes usually need to be enriched by ultracentrifugation for a measurable signal-to-noise ratio.Recently developed label-free single-molecule imaging approaches may become an real-time quantitative tool for the analysis of single exosomes and related secretion behaviors of single living cells owing to their extreme sensitivity.

The effects of hormone-mediated PI3K/AKT signaling on spermatogenesis in Sertoli cells

The phosphoinositide-3-kinase/Akt(PI3K/AKT)signaling pathway is crucial for Sertoli cell development and completing spermatogenesis.Its main role is to promote proliferation and inhibit apoptosis.Many factors activate the PI3K/AKT pathway,like hormones,such as follicle stimulating hormone(FSH),androgen,estrogen,insulin to name a few.Many of these factors have receptors inside or on the surface of Sertoli cells(SCs).This review summarizes how these hormones directly regulate the PI3K/AKT signaling pathway in SCs,which in turn affects SC proliferation and differentiation.Further,hormone-mediated PI3K/AKT signaling also stimulates SC secretion,which is essential for germ cell development,suggesting an indirect role of PI3K/AKT signaling during spermatogenesis.These functions include promoting spermatogonia proliferation and differentiation,meiosis of spermatocytes,sperm maturation,and their release.This review also provides potential hints for clinically treating male infertility issues like cryptorchidism and Sertoli cell-only syndrome.

Influence of IFNα-2b and BCG on the release of TNF and IL-1 by Kupffer cells in rats with hepatoma

INTRODUCTIONKupffer cells are residential macrophages in the liver ,which play a critical role in the maintenance of normal liver function and in immunal surveilance of hepatocellular carcinoma (HCC) and other cancers[1].The biological immune modulants have cancers[2].In our previous studies ,the combined use of biological immune modulants showed better dffects .

Biochemical properties of norepinephrine as a kind of neurotransmitter secreted by bone marrow-derived neural stem cells induced and differentiated in vitro

BACKGROUND： It has been proved by many experimental studies from the aspects of morphology and immunocytochemistry in recent years that bone marrow stromal cells （BMSCs） can in vitro induce and differentiate into the cells possessing the properties of nerve cells. But the functions of BMSCs-derived neural stem cells（NSCs） and the differentiated neuron-like cells are still unclear. OBJECTIVE： To observe whether bone marrow-derived NSCs can secrete norepinephrine （NE） under the condition of in vitro culture, induce and differentiation, and analyze the biochemical properties of BMSCs-derived NSCs. DESIGN： A non-randomized and controlled experimental observation SETTING ： Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University MATERIALS： This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5- month-old healthy New Zealand white rabbits. METHODS： This experiment was carried out in the Institute of Neuromedicine of Chinese PLA, Zhujiang Hospital, Southern Medical University. The bone marrow used in the experiment was collected from 1.5 month-old healthy New Zealand white rabbits. BMSCs of rabbits were isolated and performed in vitro culture, induce and differentiation with culture medium of NSCs and differentiation-inducing factor, then identified with immunocytochemical method. Experimental grouping： ①Negative control group： L-02 hepatic cell and RPMI1640 culture medium were used. ② Background culture group： Only culture medium of NSCs as culture solution was added into BMSCs to perform culture, and 0.1 volume fraction of imported fetal bovine serum was supplemented 72 hours later. ③Differentiation inducing factor group： After culture for 72 hours, retinoic acid and glial cell line-derived neurotrophic factors were added in the culture medium of BMSCs and NSCs as corresponding inducing factors. The level of NE in each group was detected on the day of culture and 5, 7, 14 and 20 days after culture with high performance liquid chromatography （HPLC）. The procedure was conducted 3 times in each group.Standard working curve was made according to the corresponding relationship of NE concentration and peak area. The concentration of NE every 1×10^7 cells was calculated according to standard curve and cell counting. MAIN OUTCOME MEASURES ： The level of NE of cultured cells was detected with HPLC; immunocytochemistrical identification of Nestin and neuron specific nuclear protein was performed. RESULTS： ① On the 14^th day after cell culture, BMSCs turned into magnus and round cells which presented Nestin-positive antigen, then changed into neuron-like cells with long processus and presented neuron specific nuclear protein -positive antigen at the 20^th day following culture. ② The ratio of NE concentration and peak area has good linear relationship, and regression equation was Y=1.168 36＋0.000 272 8X,r=-0.998 4. Coefficient variation （CV） was 〈 5% and the recovery rate was 92.39%（ Y referred to concentration and X was peak area）.③NE was well detached within 10 minutes under the condition of this experiment. ④ NE was detected in NSCs and their culture mediums, which were cultured for 7, 14 and 20 days respectively, but no NE in BMSCs, NSCs-free culture medium and L-02 hepatic cell which were as negative control under the HPLC examination. Analysis of variance showed that the level of NE gradually increased following the elongation of culture time （P 〈 0.01 ）. No significant difference in the level of NE existed at the same time between differentiation inducing factor group and basic culture group（P 〉 0.05）. CONCLUSION ： BMSCs of rabbits can proliferate in vitro and express Nestin antigen; They can differentiate into neuron-like cells, express specific neucleoprotein of mature neurons, synthesize and secrete NE as a kind of neurotransmitter.

The impact on secreted VEGF of Hep-2 human laryngeal cancer cell induced by Rg3

Objective：The aim of this study was to investigate the af ecting of Rg3 to secreted VEGF of human laryngeal carcinoma Hep-2 cells and its mechanism of inhibition to tumor angiogenesis. Methods：Cultured human laryngeal cancer cellline Hep-2 and human vascular endothelial cells in vitro, cells got into the period of exponential phase of growth, was diviced into 3 groups：group I （control group）, group II （DDP group）, group III （Rg3 group）. Added to the Hep-2 cells Rg3 and DDP, made Rg3 final concentration was 300μg/mL, and DDP was 3μg/mL. 48 h later, specimens from sample to be done immunocytochemistry, and the protein of VEGF in Hep-2 cells to be detected. Col ecting Hep-2 cells supernatant, some was used to measure the protein level of VEGF in Hep-2 cells supernatant by ELISA. Some was used to culture HVEC. 24 h later, cellgrowth inhibition rate of human vascular endothelial was determined by MTT. Results：The protein level of VEGF was evi-dently higher in group I compared to group II and group III, it was not only in Hep-2 cells, but also in supernatant of Hep-2 cells. There was no significantly dif erent between group II and group III. MTT results showed that, the human vascular endothelial cellgrowth inhibition rate of group I was significantly lower than that of group II and group III （P〈0.05）. At the same time the HVEC growth inhibition rate of group II was significantly lower than that of group III （P〈0.05）. Conclusion：The inhibition to tumor angiogenesis of Rg3 is stronger than traditional chemotherapy drug cisplatin. It worke by reducing the biological ef ects of secreted VEGF, But the ef ecting worke by reducing the activity of secreted VEGF itself or af ecting endothelial function of VEGF receptor or some other ways to be further studied.

Involvement of glycated albumin in adipose-derived-stem cellmediated interleukin 17 secreting T helper cell activation

BACKGROUND Advanced glycation end products(AGE)are a marker of various diseases including diabetes,in which they participate to vascular damages such as retinopathy,nephropathy and coronaropathy.Besides those vascular complications,AGE are involved in altered metabolism in many tissues,including adipose tissue(AT)where they contribute to reduced glucose uptake and attenuation of insulin sensitivity.AGE are known to contribute to type 1 diabetes(T1D)through promotion of interleukin(IL)-17 secreting T helper(Th17)cells.AIM To investigate whether lean adipose-derived stem cells(ASC)could be able to induce IL-17A secretion,with the help of AGE.METHODS As we have recently demonstrated that ASC are involved in Th17 cell promotion when they are harvested from obese AT,we used the same co-culture model to measure the impact of glycated human serum albumin(G-HSA)on human lean ASC interacting with blood mononuclear cells.IL-17A and pro-inflammatory cytokine secretion were measured by ELISA.Receptor of AGE(RAGE)together with intercellular adhesion molecule 1(ICAM-1),human leukocyte Antigen(HLA)-DR,cluster of differentiation(CD)41,and CD62P surface expressions were measured by cytofluorometry.Anti-RAGE specific monoclonal antibody was added to co-cultures in order to evaluate the role of RAGE in IL-17A production.RESULTS Results showed that whereas 1%G-HSA only weakly potentiated the production of IL-17A by T cells interacting with ASC harvested from obese subjects,it markedly increased IL-17A,but also interferon gamma and tumor necrosis factor alpha production in the presence of ASC harvested from lean individuals.This was associated with increased expression of RAGE and HLA-DR molecule by cocultured cells.Moreover,RAGE blockade experiments demonstrated RAGE specific involvement in lean ASC-mediated Th-17 cell activation.Finally,platelet aggregation and ICAM-1,which are known to be induced by AGE,were not involved in these processes.CONCLUSION Thus,our results demonstrated that G-HSA potentiated lean ASC-mediated IL-17A production in AT,suggesting a new mechanism by which AGE could contribute to T1D pathophysiology.

Role of RANTES and Its Receptor in Gastric Cancer Metastasis

This study examined the role of regulated upon activation normal T cell expressed and secreted（RANTES） and its receptor C-C chemokine receptor type 5（CCR5） in gastric cancer metastasis and the associated mechanism.The expression of RANTES and CCR5 was detected by using immunohistochemical staining and Western blotting in the gastric cancer tissues obtained from 60 gastric cancer patients with or without lymph node metastasis（n=30 in each）.The results showed that the expression levels of RANTES and CCR5 were higher in gastric cancer with lymph node metastasis than in that without metastasis（P0.05）.The expression levels of RANTES in 30 lymph nodes with cancerous invasion were higher than in 30 normal lymph nodes（P0.05）.Chemotactic test revealed that the number of migrating gastric cancer cells（n=295.0±54.6） induced by the protein of cancer-invading lymph nodes was greater than that by the protein mixture from cancer-invading lymph nodes and RANTES antibody（n=42.5±11.6）（P0.05）.RT-PCR showed that the expression levels of the main Th1 cytokines（IL-2,γ-IFN） were lower in gastric cancer with lymph node metastasis（2.22±0.90,3.26±1.15 respectively） than in that without metastasis（3.07±1.67,4.77±1.52 respectively）（P0.05）,but the expression level of the main Th 2 cytokine（IL-10） was higher in gastric cancer with lymph nodes metastasis（6.06±2.04） than in that without metastasis（4.88±1.87）（P0.05）.It was concluded that RANTES and its receptor CCR5 may contribute to gastric cancer metastasis through influencing the balance of Th1/Th2.RANTES and CCR5 may become a marker of gastric cancer metastasis.

Chronic intermittent hypoxia increases β cell mass and activates the mammalian target of rapamycin/hypoxia inducible factor 1/vascular endothelial growth factor A pathway in mice pancreatic islet

Background Growing evidence from population and clinic based studies showed that obstructive sleep apnea （OSA） and its characterizing chronic intermittent hypoxia （IH） were independently associated with the development of type 2 diabetes mellitus.However,the pathogenesis by which OSA induces glucose metabolic disorders is not clear.We determined changes in pancreatic β cell mass and the mammalian target of rapamycin （mTOR）/hypoxia inducible factor 1 （HIF-1）/ vascular endothelial growth factor A （VEGF-A） pathway following IH exposure.Methods A controlled gas delivery system regulated the flow of nitrogen and oxygen into a customized cage housing mice during the experiment.Twenty-four male wild C57BL/6J mice were either exposed to IH （n=12） or intermittent air as a control （n=12） for 56 days.Mice were anaesthetized and sacrificed after exposure,pancreas samples were dissected for immunofluorescent staining.Insulin and DAPI staining labelled islet β cells.Insulin positive area and β cell number per islet were measured.P-S6,HIF-1α and VEGF-A staining were performed to detect the activation of mTOR/HIF-1NEGF-A pathway.Results After eight weeks of IH exposure,insulin positive area increased by an average of 18.5% （P 〈0.05）.The β cell number per islet increased （92 vs.55,respectively for IH and the control groups,P 〈0.05） with no change in the size of individual β cells.Islet expression of HIF-1α and VEGF-A were higher in IH group than control group,and percentage of p-S6 positive β cell also increased after IH exposure （16.8% vs.4.6% respectively for IH and the control groups,P 〈0.05）.Conclusion The number of pancreatic β cells increased as did the activity of the mTOR/HIF-1NEGF-A pathway after exposure to IH.

Current understanding of Th2 cell differentiation and function

Helper T cell(Th)has been identified as a critical immune cell for regulating immune response since 1980s.The type 2 helper Tcell(Th2),characterized by the production of interleukin-4(IL-4),IL-5 and IL-13,plays a critical role in immune response against helminths invading cutaneous or mucosal sites.It also has a functional role in the pathophysiology of allergic diseases such as asthma and allergic diarrhea.Currently,most studies have shed light on Th2 cell function and behavior in specific diseases,such as asthma and helminthes inflammation,but not on Th2 cell itself and its differentiation.Based on different cytokines and specific behavior in recent research,Th2 cell is also regarded as new subtypes of T cell,such as IL-9 secreting T cell(Th9)and CXCR5+T follicular helper cells.Here,we will discuss the latest view of Th2 cell towards their function and the involvement of Th2 cell in diseases.