[Advance in studies on food allergy mechanism based on gut barrier].

Food allergies, as a type of adverse immune-mediated reactions to ingested food proteins, have become a serious public health issue that harms children and adults health, with increasing incidence year by year. However, without effective therapy for food allergies, doctors-have mostly advised to avoid allergens and provided symptomatic treatment. According to the findings of many studies, allergic diseases are correlated with intestinal barrier function injury, as evidenced by the significant increase in the intestinal permeability among patients with food allergies. In this paper, recent studies on correlations between food allergies and intestinal barrier functions, intestinal barrier function injury mechanisms of allergic foods and food allergy intervention strategies based on intestinal barrier functions were summarized to provide reference for laboratory researches and clinical treatment of food allergic diseases.

[Intervention effect and mechanism of compound Ginkgo biloba preparations on nonalcoholic fatty liver].

OBJECTIVE: To investigate the intervention effect and mechanism of compound Ginkgo biloba (CGB) preparations on nonalcoholic fatty liver disease (NAFLD). METHOD: The C57BL/6 mouse NAFLD model was induced with high fat diets. Since the 2nd week after modeling, the mice were orally administered with 600 and 200 mg x kg(-1) x d(-1) CGB for eight weeks. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), cholesterol (CHOL) and LPS in serum, as well as pathological changes and expression of tumor necrosis factor-alpha (TNF-alpha) in hepatic tissues were observed. Changes in intestinal tight junction proteins ZO-1, Occludin, Claudin-1 in intestinal tissues were determined under microscopy. RESULT: Compared with the normal group, the model group showed obvious fatty degeneration in rat livers, with notable increase in TNF-alpha expression (P < 0.01), significant increases in ALT, AST, TG, CHOL and LPS in serum (P < 0.01, P < 0.05), injury in intestinal tight junction proteins, and remarkable declines in ZO-1, Occludin and Claudin-1 (P < 0.01). Compared with the model group, CGB high and low dose groups showed obvious relieves in fatty degeneration in rat livers and injury in intestinal tight junction proteins, significant reductions in TNF-alpha expression (P < 0.01, P < 0.05) and AST, TG, CHOL and LPS in serum (P < 0.01, P < 0.05) and remarkable increases in ZO-1 and Occludin expressions (P < 0.05). CONCLUSION: CGB can protect intestinal tight junction proteins, reduce intestinal leakage, relieve fatty degeneration and inflammations in livers and prevent NAFLD occurrence and development.

Development of Gut Microbiota in a Mouse Model of Ovalbumin-induced Allergic Diarrhea under Sub-barrier System.

This study aimed to present a mouse model of ovalbumin (OVA) induced allergic diarrhea under a sub-barrier system and investigate the development of gut microbiota in this model. Male BALB/c mice were systemically sensitized with OVA or sham-sensitized with saline, and followed by oral OVA intubation, leading to OVA-specific acute diarrhea. Compared with sham-sensitized mice, sera OVA-specific IgG1 and total IgE in OVA-sensitized mice were dramatically elevated, and the number of mast cells was greatly increased in the jejunum of the OVA-sensitized mice. Principle component analysis of the DGGE profile showed that samples from group of OVA-sensitized mice and group of sham-sensitized mice were scattered into two different regions. Real-time PCR analysis showed that the number of 16S rRNA gene copies of Lactobacillus in the colon of OVA-sensitized mice decreased significantly, while there was no significant difference in the number of Bifidobacterium and total bacteria. In conclusion, OVA-specific allergic diarrhea was successfully induced under a sub-barrier system, and changes of allergic reactions during induction was coupled with changes in gut microbiota, especially the number of colonic Lactobacillus, but the role of gut microbiota in the development of food allergic reactions needs to be further evaluated.

An association between parvovirus B19 and Kikuchi-Fujimoto disease.

Although Kikuchi-Fujimoto disease (KFD) has a higher prevalence among Asian countries, it is a well-defined entity throughout the world. However, its etiology and pathogenesis remain undetermined. To study whether B19 infection is associated with idiopathic KFD (iKFD), we examined the presence of the viral genome and proteins in paraffin-embedded tissues of lymph nodes retrospectively from 33 iKFD patients and 16 age- and sex-matched control subjects by nested PCR (nPCR), in situ hybridization (ISH), and immunohistochemistry (IHC). B19 was detected in 87.1, 69.7, and 57.6% of iKFD specimens by nPCR, ISH, and IHC, respectively, whereas the virus was positive in only 56.3, 31.3, and 25.0% of control tissues by the respective methods (nPCR: p = 0.029; ISH: p = 0.011; IHC: p = 0.032). The IHC-ISH double-staining assay demonstrated that B19-infected cells were mainly lymphocytes and a small number of histiocytes. These results showed for the first time a high frequency of localized persistence of B19 in lymph nodes from iKFD patients, suggesting that B19 might play an important role in the pathogenesis of iKFD.

Safflower polysaccharide induces NSCLC cell apoptosis by inhibition of the Akt pathway.

Lung cancer is the leading cause of cancer death in the world. Safflower polysaccharide (SPS) has been used for the improvement of immunomodulatory activities and treatment of cancers. However, studies on the effect of SPS on the progression of lung cancer have rarely been reported. To study the antitumor effect of SPS on human lung cancer and its potential mechanism, non-small cell lung cancer cell lines (NSCLC), A549 and YTMLC-90 were treated with SPS at various concentrations ranging from 0.04 to 2.56 mg/ml and BALB/c nude tumor-bearing mice were injected intraperitoneally with SPS at concentrations ranging from 15 to 135 mg/kg. Results showed that SPS suppressed the proliferation of A549 and YTMLC-90 cells and induced apoptosis by increasing mRNA levels of bax and caspase-3, and inhibited tumor growth in vivo. SPS induced cell cycle arrest in the G2/M phase by decreasing the expression of cdc25B and cyclin B1. Moreover, SPS decreased the expression of Akt, p-Akt and PI3K. In mice, SPS injection enhanced immunomodulatory activities by increasing levels of TNF-α and IL-6 in tumor-bearing mice. Our findings suggest that SPS suppresses tumor growth by enhancing immunomodulatory activities and blocking the PI3K/Akt pathway. This study provides new insight into the anticancer mechanism of SPS.

[Apoptosis of multiple myeloma cells induced by gossypol acetic acid in vitro and its mechanism].

This study was aimed to investigate the apoptosis effect of gossypol acetic acid on classic human multiple myeloma RPMI8226 cell line in vitro and its mechanism. The inhibitory effect on proliferation of RPMI8226 cells was evaluated by means of MTT assay. Cytotoxic effect and apoptosis was identified and analyzed with the aid of transmission electron microscopy, mitochondria membrane potential (MMP) and DNA gel electrophoresis. Meanwhile, Western-blot assay was used to detect the changes of several key cell apoptosis regulatory proteins such as BAX, caspase-3 and caspase-8 in these cells before and after treatment. The results showed that low concentrations of gossypol acetic acid (> 16 micromol/L) could suppress the proliferation and induce the apoptosis in RPMI8226 cells effectively. At the same time, gossypol acetic acid could also down-regulate the mitochondrial membrane potential, up-regulate the expression of the apoptosis-related protein such as BAX and caspase-3. It is concluded that the gossypol acetic acid can selectively induce proliferation inhibition and apoptosis of multiple myeloma RPMI8226 cells with a smaller dose.

Gossypol-Induced Differentiation in Human Leukemia HL-60 Cells.

The main treatment of leukemia is traditional radiochemotherapy, which is associated with serious side effects. In the past twenty years, differentiation was found as an important effective measure to treat leukemia with fewer side effects. Gossypol, a natural compound which has been used as an effective contraceptive drug, has been proposed to be a potent drug to treat leukemia, but the differentiation effect has not been studied. In the present study, we investigated the pro-differentiated effects, in vitro, of gossypol on the classic human myeloid leukemia HL-60 cell line. The effects of gossypol were investigated by using morphological changes, nitroblue tetrazolium (NBT) reduction, surface markers, cell-cycle analysis and Western blot analysis, etc. When HL-60 cells were incubated with low concentrations of gossypol (2-5µM) for 48hr, a prominent G0/G1 arrest was observed. At 96 hr of treatment, 90% of HL-60 cells differentiated, as evidenced by morphological changes, NBT reduction, and increase in cell surface expression of some molecules were detected. This study is the first to identify gossypol's pro-differentiated effects on the leukemia cell line, and it induced differentiation through the PBK (PDZ-binding kinase)/TOPK (T-LAKcell-originated protein kinase) (PBK/TOPK) pathway. It is concluded that gossypol could induce differentiation in the leukemia HL-60 cells, and it may be a potential therapeutic agent, chemoprevention or chemotherapeutic adjuvant especially in combination drug therapy for leukemia.

[Effect of bone marrow stromal cells on the apoptotic sensitivity of HL-60 and HL-60/VCR cells].

This study was aimed to investigate the effects of human bone marrow fibroblastoid stromal cell line (HFCL) on chemosensitivity of acute myeloid leukemia sensitive HL-60 cell line and multidrug-resistant (MDR) HL-60/VCR cell line in vitro co-culture. Setting up co-culture system of HL-60 or HL-60/VCR cells in direct contact with HFCL cells, or with HFCL cells separated by transwell, and exposing HL-60 or HL-60/VCR cells to different concentrations of topotecon (TPT), morphologic evidence for apoptosis was determined by staining with Wright-Giemsa stain and acridine orange/ethidium bromide (AO/EB). Cell cycle, sub-G(1) and annexin V FITC staining were detected by flow cytometry. The expression of active caspase-3, Bcl-2 and Pgp was detected by Western blot. The results showed that HL-60 or HL-60/VCR cells treated by TPT revealed characteristic apoptotic morphological changes by Wright-Giemsa and AO/EB staining. The percentage of annexin V-positive cells and apoptotic cells decreased when they were cocultured with HFCL cells. The proportion of G(0)/G(1) HL-60 or HL-60/VCR cells treated by TPT increased and the sub-G(1) appeared significantly, but apoptotic and sub-G cells reduced after direct contact with HFCL cells. Meanwhile, although HL-60 or HL-60/VCR cells treated by TPT expressed activated caspase-3, and the expression of Bcl-2 decreased, the expression of activated caspase-3 decreased and Bcl-2 increased after direct contact with HFCL cells. In conclusion, HFCL stromal cells can prevent TPT-induced apoptosis in HL-60 and HL-60/VCR cells via modulation of Bcl-2 and active caspase-3.

[Effects of HCMV on phenotypes of parotid duct epithelial cells and its mechanisms].

OBJECTIVE: To investigate the effects of HCMV infection on phenotypes of parotid duct epithelial cells and relative mechanisms. METHODS: The expressions of immediate early antigen of HCMV, pan cytokeratin and cathepsin D etc. were detected by immunohistochemical staining in tissues of parotid cytomegalic inclusion disease. RESULTS: Cytokeratin which acts as an epithelial marker became negative while staining of Cathepsin D was intensified in parotid duct epithelial cells after infected by HCMV. CONCLUSION: It demonstrated that cytokeratin was lost through over-expression of Cathepsin D in parotid duct epithelial cells infected by HCMV.

[Human cytomegalovirus inhibits proliferation of duct epithelial cells of human salivary gland].

OBJECTIVE: To investigate the effects of human cytomegalovirus (HCMV) on the proliferation of duct epithelial cells of human salivary gland (HSG). METHODS: The expression of proliferating cell nuclear antigen (PCNA) and p53 were studied in 11 cases of parotid cytomegalic inclusive disease (PCID) using immunohistochemical staining method. The effects of human cytomegalovirus (HCMV) on the proliferation of HSG were investigated by MTT method in vitro. The expression of PCNA in HSG infected by HCMV was examined using immunocytochemical staining and Western blotting. RESULTS: PCNA was expressed weakly in most of megalic inclusion cells which were positive for HCMV, while all the megalic inclusion cells were p53 negative in all 11 cases of PCID. HCMV inhibited proliferation of HSG in vitro in a time dependent and dose dependent manner. Down-regulation of PCNA was shown in infected cells. CONCLUSION: HCMV inhibits proliferation of HSG and down-regulation of PCNA may be an expression of the inhibition.