Construction of Toxoplasma gondii SRS29C nucleic acid vaccine and comparative immunoprotective study of an SRS29C and SAG1 combination.

Toxoplasma gondii is an intracellular protozoan parasite that infects all nucleated cells except the red blood cells. Currently, nucleic acid vaccines are being widely investigated in Toxoplasma gondii control, and several nucleic acid vaccine candidate antigens have shown good protection in various studies. The aim of this study was to construct a nucleic acid vaccine with Toxoplasma gondii SRS29C as the target gene. We explored the nucleic acid vaccine with Toxoplasma surface protein SRS29C and the combined gene of SRS29C and SAG1 and evaluated its immunoprotective effect against Toxoplasma gondii. To amplify the gene fragment and clone it to the expression vector, the recombinant plasmid pEGFP-SRS29C was constructed by PCR. Eukaryotic cells were transfected with the plasmid, and the expression of the target protein was assessed using the Western blot method. The level of serum IgG was determined via ELISA, and the splenic lymphocyte proliferation ability was detected using the CCK-8 method. The percentages of CD4+ and CD8+ T cells were measured by flow cytometry. Mice were immunised three times with single-gene nucleic acid vaccine and combination vaccine. Splenic lymphocytokine expression was determined using ELISA kits. The mice's survival time was monitored and recorded during an in vivo insect assault experiment, and the vaccine's protective power was assessed. The outcomes showed that PCR-amplification of an SRS29C gene fragment was successful. The 4,733-bp vector fragment and the 1,119-bp target segment were both recognised by double digestion. Additionally, after transfection of the recombinant plasmid pEGFP-SRS29C, Western blot examination of the extracted protein revealed the presence of a target protein strip at 66 kDa. The test results demonstrated that the IgG content in the serum of the pEGFP-SRS29C group and the co-immunization group was significantly higher than that of the PBS group and the empty vector group. The IgG potency induced by the co-immunization group was higher than that of the pEGFP-SRS29C group and the pEGFP-SAG1 group, the number of splenic lymphocyte proliferation number was higher than that of the PBS group and the empty vector group. The CD4+/CD8+ T ratio was higher than that of the PBS group and the empty vector group. The expression of IFN-γ and TNF-α in the splenocytes of the pEGFP-SRS29C group and the combined immunisation group was significantly higher following antigen stimulation. In the worm attack experiments, mice in the PBS and empty vector groups perished within 9 days of the worm attack, whereas mice in the pEGFP-SRS29C group survived for 18 days, mice in the pEGFP-SAG1 group survived for 21 days, and mice in the co-immunization group survived for 24 days. This demonstrates that the constructed Toxoplasma gondii nucleic acid vaccine pEGFP-SRS29C and the combined gene vaccine can induce mice to develop certain humoral and cellular immune responses, and enhance their ability to resist Toxoplasma gondii infection.

Aggravation of food allergy symptoms by treatment with acrylamide in a mouse model.

Acrylamide (AA) forms during the thermal processing of food, but adversely affects human health. As the consumption of heat-processed foods increases, the potentially harmful effect of AA on food allergies needs to be clarified. Here, we investigated how AA affects the allergenicity of OVA in vivo using a mouse model of orally induced OVA allergy. AA enhanced OVA-induced food allergic response by increasing IgE, IgG, IgG1, histamine, and MCP-1. AA promoted the Th2 cell response to modulate the imbalance in Th1/Th2. Furthermore, AA reduced the expression of intestinal tight junction proteins, and disrupted the permeability of the intestine, which impaired the intestinal epithelial barrier, resulting in more OVA crossing it. These actions aggravated the allergic reaction of OVA. In conclusion, this study confirmed the potentially harmful effect of AA on food allergy.

Modulating the allergenicity and functional properties of peanut protein by covalent conjugation with polyphenols.

Peanut protein is a common food allergen. Our previous study demonstrated that the allergenicity of Ara h1 declines after covalent conjugation with polyphenols in vitro; however, how polyphenols affect the structure, function, and allergenicity of peanut protein extract (PPE) after covalent conjugating needs clarifying. Here, we assessed how the structure, function, and allergenicity of PPE changed after covalent conjugation with epigallocatechin-3-gallate (PPE-EGCG) and chlorogenic acid (PPE-CA). PPE covalently conjugated with EGCG and CA using the alkali treatment method. Multi-spectroscopy showed that the structure of PPE-EGCG/CA conjugate changed, becoming less folded. In contrast, the functional properties of PPE significantly improved. The allergenicity of PPE-EGCG/CA significantly declined in vitro and in vivo experiments. Our findings confirm that covalent conjugation of PPE with EGCG and CA reduces the allergenicity and improves the functional properties of PPE by changing the structure of the protein.

Heidihuangwan alleviates renal fibrosis in rats with 5/6 nephrectomy by inhibiting autophagy.

Renal fibrosis is a common pathway for the progression of various chronic kidney diseases (CKD), and the formation and deterioration will eventually lead to end-stage renal failure, which brings a heavy medical burden to the world. HeidihuangWan (HDHW) is a herbal formulation with stable and reliable clinical efficacy in the treatment of renal fibrosis. However, the mechanism of HDHW in treating renal fibrosis is not clear. In this study, we aimed to investigate the mechanism of HDHW to improve renal fibrosis. Wistar rats were randomly divided into the normal control group, 5/6 Nephrectomy group, astragaloside IV (AS-IV) group, HDHW group, and HDHW + IGF-1R inhibitor (JB1) group. Except for the normal control group, the rat renal fibrosis model was established by 5/6 nephrectomy and intervened with drugs for 8 weeks. Blood samples were collected to evaluate renal function. Hematoxylin-Eosin (HE), Periodic Acid-Schiff (PAS), Modified Masson's Trichrome (Masson) staining were used to evaluate the pathological renal injury, and immunohistochemistry and Western blotting were used to detect the protein expression of renal tissue. The results showed that HDHW was effective in improving renal function and reducing renal pathological damage. HDHW down-regulated the levels of fibrosis marker proteins, including α-smooth muscle actin (α-SMA), vimentin, and transforming growth factors-ß(TGF-ß), which in turn reduced renal fibrosis. Further studies showed that HDHW down-regulated the expression of autophagy-related proteins Beclin1 and LC3II, indicating that HDHW inhibited autophagy. In addition, we examined the activity of the class I phosphatidylinositol-3 kinase (PI3K)/serine-threonine kinase (Akt)/mTOR pathway, an important signaling pathway regulating autophagy, and the level of insulin-like growth factor 1 (IGF-1), an upstream activator of PI3K/Akt/mTOR. HDHW upregulated the expression of IGF-1 and activated the PI3K/Akt/mTOR pathway, which may be a vital pathway for its inhibition of autophagy. Application of insulin-like growth factor 1 receptor (IGF-1R) inhibitor further confirmed that the regulation of autophagy and renal fibrosis by HDHW was associated with IGF-1-mediated activation of the PI3K/Akt/mTOR pathway. In conclusion, our study showed that HDHW inhibited autophagy by upregulating IGF-1 expression, promoting the binding of IGF-1 to IGF-1R, and activating the PI3K/Akt/mTOR signaling pathway, thereby reducing renal fibrosis and protecting renal function. This study provides support for the application and further study of HDHW.

Functional and Allergenic Properties Assessment of Conalbumin (Ovotransferrin) after Oxidation.

Conalbumin (CA) is an iron-binding egg protein that has various bioactivities and causes major allergenicity in humans. This study investigated how oxidation affects the multiple functional properties of CA. The lipid peroxidation method was used to prepare treated CA [2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)-CA and acrolein-CA] complexes. CA induced structural changes through oxidation. These changes enhanced the digestibility, rate of endocytosis in dendritic cells, and emulsifying and foaming properties of CA. ELISA and immunoblot analysis showed that the complexes reduced the IgE-binding ability of CA through lipid oxidation. KU812 cell assays showed that modification by AAPH and acrolein caused the release of IL-4 and histamine to decline. In conclusion, oxidation treatment modified the functional and structural properties of CA, reducing allergenicity during processing and preservation.

A new method to reduce allergenicity by improving the functional properties of soybean 7S protein through covalent modification with polyphenols.

The 7S fraction contains several major allergens of soybean protein. Here, the effects of covalent modification by chlorogenic acid (CHA) and (-)-epigallo-catechin 3-gallate (EGCG) on the allergenicity and functional properties of soybean 7S protein were investigated. Conjugation with EGCG and CHA resulted in the formation of cross-linked protein polymers and changes to the structures of the protein, which might mask or destroy the epitopes on it. In vitro analysis revealed that modification by polyphenols noticeably reduced IgE binding activity and histamine release. In vivo analysis showed that modification led to milder anaphylactic shock symptoms and minor damage of the intestine in mice, with reducing IgG, IgE, IgG1, mMCP-1, and histamine levels. The allergic response was also suppressed by the repression of IFN-γ, IL-4, and IL-5 and the up-regulation of IL-10 and TGF-ß in the conjugate groups. Furthermore, modification enhanced antioxidant, emulsion, foaming capacity, and foam stability of the protein.

Dynamics of heart rate variability in patients with type 2 diabetes mellitus during spinal anesthesia using dexmedetomidine.

Objective The aim of this study was to investigate the heart rate variability (HRV) in patients with Type 2 diabetes mellitus (T2DM) who underwent spinal anesthesia using dexmedetomidine for lower limb surgery. METHODS: T2DM patients were divided into two groups, namely the controlled group (HbA1c < 7%) and the uncontrolled group (HbA1c > 7%) according to the glycosylated hemoglobin (HbA1c) level, and patients with non-T2DM as the normal group, 30 cases in each group. The HRV, including low-frequency (LF) power, high-frequency (HF) power, total power (TP) and LF/HF ratio, was measured 10 min before spinal anesthesia (T0) and 10 min (T1), 20 min (T2) and 30 min (T3) after spinal anesthesia with dexmedetomidine. RESULTS: We observed that TP, LF, and HF power in the uncontrolled group were remarkably lower than that in the other two groups at T0 (P < 0.05). In the controlled group, the LF power dropped markedly at T1-2 than the normal group. The LF power in the uncontrolled group did not show significant change at all time points, but was significantly lower than the level in the controlled group at T1-3. The HF power in the three groups did not alter markedly at different time points, but the HF power in the uncontrolled group was markedly lower than that in the normal group and the controlled group. In all three groups, the LF/HF ratio dropped markedly at T1-3 with no markedly difference between the groups. The heart rhythms in the three groups showed a decrease trend after spinal anesthesia with no markedly difference between the groups. The SBP and DBP at T1-3 in the three groups were markedly lower than that at T0, and the systolic blood pressure (SBP) and diastolic blood pressure (DBP) at T1-3 in the uncontrolled group were markedly higher than those in the normal group and the controlled group. CONCLUSION: Spinal anesthesia with dexmedetomidine affects autonomic nerve function in patients whose glycemic control is better during the lower limb surgery in T2DM patients, but has no significant effect on patients who fail to do so. For such patients, spinal anesthesia can result in a markedly increase in SBP and DBP.

Reducing the Allergenicity of α-Lactalbumin after Lipid Peroxidation.

This study analyzed the effect of lipid peroxidation using 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) and acrolein on the in vitro and in vivo allergenicity of α-lactalbumin (α-La). The structure of oxidized α-La was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, fluorescence spectroscopy, and circular dichroism, whereas the changes in the allergenic properties were evaluated. Lipid peroxidation induced changes to the structural properties that might destroy and/or mask α-La epitopes. In comparison to native α-La, oxidation complexes caused a decrease in the immunoglobulin E (IgE) binding capacity, as observed via immunoblotting. Moreover, the capacity to release mediators and cytokines from KU812 cells was also greatly reduced. In vivo, oxidation with AAPH and acrolein caused a significant reduction in IgE, IgG, IgG1, mast cell protease 1, and plasma histamine, along with the reduction of mast surface c-Kit+ and FcεRI+ expression. Therefore, these results indicate that oxidation via AAPH and acrolein can potentially reduce the allergenicity of α-La, which can help with the better understanding of the changes in allergenicity of milk allergen by lipid peroxidation.

An empirical investigation of the utilitarian, social benefits in LBS information disclosure-The moderating effect of the gender based social role theory.

The prior studies on information disclosure in location-based services (LBS) suggested that the perceived benefits of information disclosure in LBS were manifested by three benefits, namely, locatability, personalization, and social benefits. The three benefits might affect information disclosure intention differently. As an extension, individual factors, such as gender, may affect the relationship. However, according to literature, little research has investigated on the combined influence of the three benefits on the information disclosure intention in LBS with the gender as a moderator. Based upon the self-determination and social role theories, this study intends to bridge the gap empirically. The hypotheses are largely supported by 215 respondents. Unexpectedly, the research findings show that for females, locatability and personalization are more important in predicting their information disclosure intention, whereas for males, the social benefit has more of an impact on information disclosure intention, which is opposite to the hypotheses and convention. Furthermore, the research findings indicate that the behaviors of males and females may conform to the roles distributed within a society of this information age rather than to the personalities of the individuals. Finally, the implications are presented.

[Construction of a vector targeting integrase of human immunodeficiency virus type 1 (HIV-1) used for screening peptide drug].

Objective To obtain the expression vector, which could be used for screening peptide drug against human immunodeficiency virus type 1 (HIV-1) integrase (IN) with bimolecular fluorescence complementation (BiFc). Methods Full-length IN sequence was amplified using high-fidelity PCR with the template pMDL vector, following with the insertion of target sequence into pBiFc-VN173 vector. Moreover, the recombinant vector pBiFc-VN173-IN was further confirmed by double enzyme digestion and sequencing. Compared with empty control, expression of IN from pBiFc-VN173-IN in HEK293T cells was validated by Western blotting and immunofluorescence assay (IFA). Results The pBiFc-VN173-IN vector, which could drive the ectopic expression of IN, was successfully obtained through high-fidelity PCR, vector construction and confirmation. In addition, Western blot analysis and IFA validated the ectopic expression of IN in HEK293T cells after transfection. Conclusion The pBiFc-VN173-IN vector has been successfully obtained, and it will be helpful for screening specific peptides against IN using BiFc.

Slit2 and Robo1 induce opposing effects on metastasis of hepatocellular carcinoma Sk-hep-1 cells.

The neural guidance molecular, Slit2, and its cognate receptor, Robo1, play critical roles in the development of the nervous system, nevertheless, their functions are not limited to this system. Numerous studies have shown decreased Slit2 expression in a wide variety of cancers, highlighting its potential as a tumor suppressor. However, the Slit2/Robo1 signaling axis was reported to induce either suppressive or stimulatory effects on tumor growth and metastasis, depending on cellular context. There is a paucity of information on the effects of the Slit2/Robo1 signaling axis on the growth and metastasis of human hepatocellular carcinoma (HCC). Large-scale data mining of the Oncomine database has revealed heterogeneous expression of Slit2 in HCC. We screened the Sk-hep-1, a cell line showing a relatively high level of Slit2, and low level of Robo1 expression. After Slit2 knockdown and Robo1 overexpression in these cells, we found Slit2 and Robo1 exerted opposing effects on tumor growth and metastasis both in in vitro and in vivo models. Slit2 knockdown and Robo1 overexpression in Sk-hep-1 cells promoted tumor growth and metastasis, suggesting a negative and positive role for Slit2 and Robo1, respectively, in tumor progression. Robo1 overexpression upregulated matrix metalloproteinase (MMP)2, -9 and membrane-type1 MMP (MT1-MMP) expression, stimulated MMP2, but not MMP9 activation, and downregulated expression of TIMP1 and 2. The PI3K/Akt signaling pathway is of importance in regulating MMP2 expression in Sk-hep-1 cells, since Robo1 overexpression stimulated phosphorylation of Akt while the PI3K inhibitor LY294002, significantly inhibited the upregulation of MMP2 and also the enhanced cell invasion induced by Robo1 overexpression. We postulate that Robo1 promotes tumor invasion partly by the upregulation of MMP2 after activation of PI3K/Akt signaling pathway. Notably, Slit2 knockdown caused the upregulation of Robo1 expression both at the mRNA and protein levels. Thus, the stimulatory effects of Slit2 knockdown on tumor progression can be ascribed, at least in part, to the upregulation of Robo1 and its positive role in tumor progression.

Effects of Slit3 silencing on the invasive ability of lung carcinoma A549 cells.

Slit proteins function as chemorepellents in axon guidance and neuronal migration by binding to cognate Robo receptors. The Slit/Robo signaling pathway is also involved in the regulation of tumor cell metastasis. However, whether the Slit/Robo signaling pathway exerts prometastatic or antimetastasis functions remains controversial. To date, most of the research on Slit/Robo has focused on Slit2, and the effects of Slit3 on metastasis remain largely unknown. Based on the Oncomine database, overall expression of Slit3 is low in tumor tissues compared to its level in normal tissues. The underlying mechanism for slit3 silencing in tumor tissues is likely related to hypermethylation of the slit3 promoter. However, lung carcinomas appear to be an exception. Several studies have reported that the frequency of Slit3 methylation in lung cancers is far lower than the frequency of Slit2. In the present study, high Slit3 expression at the mRNA level, yet not at the protein level, was detected in lung adenocarcinoma A549 cells. The function of Slit3 in tumor migration and invasion was examined by silencing of Slit3 expression in A549 cells. Silencing of Slit3 promoted proliferation, migration and invasion of A549 cells and induced epithelial-mesenchymal transition by downregulation of E-cadherin and upregulation of vimentin. The inhibitory effects of Slit3 on tumor migration and invasion are likely related to matrix metalloproteinases (MMPs). Silencing of Slit3 in the A549 cells enhanced MMP2 and MMP9 expression. These results indicate that Slit3 is a potential tumor suppressor in lung adenocarcinoma.