Expression, purification, and functional verification of recombinant human glycoprotein hormone beta 5/alpha 2 fusion protein in CHO-S cells / 中国药理学通报

Aim To express and purify recombinant hCGH-CTP fusion protein in high-density suspension culture of Chinese hamster ovary cells (CHO-S), and to verify the lipid accumulation effect of rhCGH-CTP on 3T3-L1 mature adipocytes. Methods The recombinant protein expression vector (pcDNA3. 1-rhCGH-CTP) was constructed, achieved by fusing the human glycoprotein hormone beta 5/alpha 2 cDNA with CTP Linker. The expression plasmid was transiently transfected into the suspended CHO-S to express rhCGH-CTP protein and then purified, and the protein biological activity was verified. Intervention with 3T3-L1 mature adipocyte cells for 24 h was performed to detect the changes of intracellular triglyceride (TG) level. Results Western blot results showed that rhCGH-CTP protein was successfully expressed in CHO-S cells, and the yield was up to 715. 4 mg • L~ . The secreted protein was purified by AKTA pure system with higher purity that was up to 90% as identified by SDS-PAGE. In addition, the intracellular cAMP content of mature adipocytes with high expression of TSHR gene significantly increased after intervention with different concentrations of rhCGH-CTP protein by ELISA kit, indicating that rhCGH-CTP protein had biological activity. Oil red 0 staining showed that compared with the control group, the lipid content of mature adipocytes in the intervention groups with different concentrations of rhCGH-CTP protein significantly decreased (P < 0. 05) . Conclusions The rhCGH-CTP protein has been successfully expressed and purified with biological activity, and effectively reduce TG. This research provides an important theoretical basis for further revealing the physiological role of CGH protein and its potential application in clinical practice.

Impairment of spermatogenesis and sperm motility by the high-fat diet-induced dysbiosis of gut microbes.

OBJECTIVE: High-fat diet (HFD)-induced metabolic disorders can lead to impaired sperm production. We aim to investigate if HFD-induced gut microbiota dysbiosis can functionally influence spermatogenesis and sperm motility. DESIGN: Faecal microbes derived from the HFD-fed or normal diet (ND)-fed male mice were transplanted to the mice maintained on ND. The gut microbes, sperm count and motility were analysed. Human faecal/semen/blood samples were collected to assess microbiota, sperm quality and endotoxin. RESULTS: Transplantation of the HFD gut microbes into the ND-maintained (HFD-FMT) mice resulted in a significant decrease in spermatogenesis and sperm motility, whereas similar transplantation with the microbes from the ND-fed mice failed to do so. Analysis of the microbiota showed a profound increase in genus Bacteroides and Prevotella, both of which likely contributed to the metabolic endotoxaemia in the HFD-FMT mice. Interestingly, the gut microbes from clinical subjects revealed a strong negative correlation between the abundance of Bacteroides-Prevotella and sperm motility, and a positive correlation between blood endotoxin and Bacteroides abundance. Transplantation with HFD microbes also led to intestinal infiltration of T cells and macrophages as well as a significant increase of pro-inflammatory cytokines in the epididymis, suggesting that epididymal inflammation have likely contributed to the impairment of sperm motility. RNA-sequencing revealed significant reduction in the expression of those genes involved in gamete meiosis and testicular mitochondrial functions in the HFD-FMT mice. CONCLUSION: We revealed an intimate linkage between HFD-induced microbiota dysbiosis and defect in spermatogenesis with elevated endotoxin, dysregulation of testicular gene expression and localised epididymal inflammation as the potential causes. TRIAL REGISTRATION NUMBER: NCT03634644.

Protective effects of ginsenoside Rg1 against hydrogen peroxide-induced injury in human neuroblastoma cells.

The active ingredient of ginseng, ginsenosides Rg1, has been shown to scavenge free radicals and improve antioxidant capacity. This study hypothesized that ginsenosides Rg1 has a protective role in human neuroblastoma cells injured by H2O2. Ginsenosides Rg1 at different concentrations (50 and 100 µM) was used to treat H2O2 (150 µM)-injured SH-SY5Y cells. Results demonstrated that ginsenoside Rg1 elevated the survival rate of SH-SY5Y cells injured by H2O2, diminished the amount of leaked lactate dehydrogenase, and increased superoxide dismutase activity. Ginsenoside Rg1 effectively suppressed caspase-3 immunoreactivity, and contributed to heat shock protein 70 gene expression, in a dose-dependent manner. These results indicate that ginsenoside Rg1 has protective effects on SH-SY5Y cells injured by H2O2 and that its mechanism of action is associated with anti-oxidation and the inhibition of apoptosis.

Aß-induced microglial cell activation is inhibited by baicalin through the JAK2/STAT3 signaling pathway.

Baicalin has shown multiple neuroprotective biological activities, including antiapoptotic and anti-inflammatory functions in neurodegeneration diseases. However, whether baicalin can regulate Aß-induced microglial activation or inhibit inflammatory cytokine secretion has not been confirmed. We demonstrated that baicalin can inhibit beta amyloid peptides (Aß42)-induced BV2 microglial cell proliferation, reduce the expression of CD11b, decrease chemotactic ability of BV2 cells and significantly inhibit the secretion of IL-6, TNF-α and NO. Moreover, baicalin pretreatment can effectively inhibit Aß-induced phosphorylation of JAK2 and STAT3. Baicalin can inhibit Aß-induced microglial cell activation by regulating the JAK2/STAT3 signaling pathway in AD transgenic mice. The modulation of microglial proliferation, activation and secretion by baicalin could be a promising therapeutic option for the treatment of Alzheimer's disease.

Role of synaptic activity in the regulation of amyloid beta levels in Alzheimer's disease.

Alzheimer's disease (AD) is the most common form of dementia. Accumulation of amyloid-beta (Aß) peptides is regarded as the critical component associated with AD pathogenesis, which is derived from the amyloid precursor protein (APP) cleavage. Recent studies suggest that synaptic activity is one of the most important factors that regulate Aß levels. It has been found that synaptic activity facilitates APP internalization and influences APP cleavage. Glutamatergic, cholinergic, serotonergic, leptin, adrenergic, orexin, and gamma-amino butyric acid receptors, as well as the activity-regulated cytoskeleton-associated protein (Arc) are all involved in these processes. The present review summarizes the evidence for synaptic activity-modulated Aß levels and the mechanisms underlying this regulation. Interestingly, the immediate early gene product Arc may also be the downstream signaling molecule of several receptors in the synaptic activity-modulated Aß levels. Elucidating how Aß levels are regulated by synaptic activity may provide new insights in both the understanding of the pathogenesis of AD and in the development of therapies to slow down the progression of AD.

RXRα inhibits the NRF2-ARE signaling pathway through a direct interaction with the Neh7 domain of NRF2.

The transcription factor NRF2 (NFE2L2) is a pivotal activator of genes encoding cytoprotective and detoxifying enzymes that limit the action of cytotoxic therapies in cancer. NRF2 acts by binding antioxidant response elements (ARE) in its target genes, but there is relatively limited knowledge about how it is negatively controlled. Here, we report that retinoic X receptor alpha (RXRα) is a hitherto unrecognized repressor of NRF2. RNAi-mediated knockdown of RXRα increased basal ARE-driven gene expression and induction of ARE-driven genes by the NRF2 activator tert-butylhydroquinone (tBHQ). Conversely, overexpression of RXRα decreased ARE-driven gene expression. Biochemical investigations showed that RXRα interacts physically with NRF2 in cancer cells and in murine small intestine and liver tissues. Furthermore, RXRα bound to ARE sequences in the promoters of NRF2-regulated genes. RXRα loading onto AREs was concomitant with the presence of NRF2, supporting the hypothesis that a direct interaction between the two proteins on gene promoters accounts for the antagonism of ARE-driven gene expression. Mutation analyses revealed that interaction between the two transcription factors involves the DNA-binding domain of RXRα and a region comprising amino acids 209-316 in human NRF2 that had not been defined functionally, but that we now designate as the NRF2-ECH homology (Neh) 7 domain. In non-small cell lung cancer cells where NRF2 levels are elevated, RXRα expression downregulated NRF2 and sensitized cells to the cytotoxic effects of therapeutic drugs. In summary, our findings show that RXRα diminishes cytoprotection by NRF2 by binding directly to the newly defined Neh7 domain in NRF2.

Shuyusan-containing serum protects SH-SY5Y cells against corticosterone-induced impairment.

The Chinese herb Shuyusan, whose main constituent is jasminoidin, has been shown to protect SH-SY5Y cells against corticosterone-induced damage. SH-SY5Y cells injured by 400 µmol/L corticosterone were treated with 5 and 30 µg/mL Shuyusan-containing serum. Results revealed that Shuyusan-containing serum elevated the survival rate of SH-SY5Y cells, reduced Bax expression, increased Bcl-2 expression, markedly elevated brain-derived neurotrophic factor mRNA expression, and blocked cell apoptosis. Moreover, the effect of high-dose (30 µg/mL) Shuyusan-containing serum was more remarkable. Therefore, Shuyusan-containing serum appears to protect SH-SY5Y cells against corticosterone-induced impairment by adjusting the expression of apoptosis-associated proteins and brain-derived neurotrophic factor. Moreover, high-dose Shuyusan-containing serum has a protective effect on high-dose corticosterone-induced impairment.

Anti-tumor effect of rutin on human neuroblastoma cell lines through inducing G2/M cell cycle arrest and promoting apoptosis.

AIMS: To further investigate the antineuroblastoma effect of rutin which is a type of flavonoid. METHODS: The antiproliferation of rutin in human neuroblastoma cells LAN-5 were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Chemotaxis of LAN-5 cells was assessed using transwell migration chambers and scratch wound migration assay. The cell cycle arrest and apoptosis in a dose-dependent manner was measured by flow cytometric and fluorescent microscopy analyses. The apoptosis-related proteins BAX and BCL2 as well as MYCN mRNA express were determined by RT-PCR analysis. Secreted TNF- α level were determined using specific enzyme-linked immunosorbent assay kits. RESULTS: Rutin significantly inhibited the growth of LAN-5 cells and chemotactic ability. Flow cytometric analysis revealed that rutin induced G2/M arrest in the cell cycle progression and induced cell apoptosis. The RT-PCR showed that rutin could decrease BCL2 expression and BCL2/BAX ratio. In the meantime, the MYCN mRNA level and the secretion of TNF- α were inhibited. CONCLUSION: These results suggest that rutin produces obvious antineuroblastoma effects via induced G2/M arrest in the cell cycle progression and induced cell apoptosis as well as regulating the expression of gene related to apoptosis and so on. It supports the viability of developing rutin as a novel therapeutic prodrug for neuroblastoma treatment, as well as providing a new path on anticancer effect of Chinese traditional drug.

[Effect of intensive rosuvastatin therapy on adhesion molecules and the upstream mechanism in patients with peripheral atherosclerosis].

OBJECTIVE: To investigate the effect of intensive rosuvastatin therapy on adhesion molecules in patients with peripheral atherosclerosis and explore the possible upstream mechanism. METHODS: Twenty asymptomatic patients with peripheral atherosclerosis were enrolled and given 5-20 mg/day rosuvastatin for 3 months. Before and after the treatment, the lipid profile and plasma vascular cell adhesion molecule-1 (VCAM-1) levels were examined. The expression of intercellular adhesion molecule-1 (ICAM-1) in the mononuclear cells was measured using flow cytometry, and the mRNA and protein expressions of peroxisome proliferator-activated receptor γ (PPARγ) were detected using RT-PCR and Western blotting, respectively. RESULTS: Compared with the baseline levels, ICAM-1 expression decreased and PPARγ protein expression increased in the lymphocytes. Rosuvastatin therapy did not produce obvious effects on plasma VCAM-1 level or ICAM-1 expression in the monocytes in these patients. CONCLUSION: Rosuvastatin produces anti-inflammatory effects by decreasing the expression of ICAM-1 in mononuclear cells, and its upstream mechanism may involve the PPARγ pathway.

Antidepressant-like effects of shuyusan in rats exposed to chronic stress: effects on hypothalamic-pituitary-adrenal function.

This study was to investigate antidepressant activities of Shuyusan (a Chinese herb), using a rats model of depression induced by unpredictable chronic mild stress (UCMS). The administration groups were treated with Shuyusan decoction for 3 weeks and compared with fluoxetine treatment. In order to understand the potential antidepressant-like activities of Shuyusan, tail suspension test (TST) and forced swimming test (FST) were used as behavioral despair study. The level of corticotropin-releasing factor (CRH), adrenocorticotropic hormone (ACTH), corticosterone (CORT) and hippocampus glucocorticoid receptor expression were examined. After modeling, there was a significant prolongation of immobility time in administration groups with the TST and FST. High-dose Shuyusan could reduce the immobility time measured with the TST and FST. The immobility time in high-dose herbs group and fluoxetine group was increased significantly compared with the model group. After 3 weeks herbs fed, the serum contents level of CRH, ACTH, and CORT in high-dose herb group was significantly decreased compared to the model group. The result indicated that Shuyusan had antidepressant activity effects on UCMS model rats. The potential antidepressant effect may be related to decreasing glucocorticoid levels activity, regulating the function of HPA axis, and inhibiting glucocorticoid receptor expression in hippocampus.

[Comparative proteomic analysis of hippocampus between chronic cerebral ischemia rats and normal controls].

OBJECTIVE: To explore the pathogenesis of brain damage after chronic cerebral ischemia through analysis of the differences in proteins expression in hippocampus between chronic cerebral ischemia rats and normal rats. METHODS: The chronic cerebral ischemia model was established by ligating the bilateral common carotid arteries.Twenty rats were randomly divided into a model group (n=10)and a sham operation group(n=10). Four weeks later, the differences of proteins expression in hippocampus between model group and sham operation group were analyzed by two dimensional polyacryalmide gel electrophoresis and ultraflex TOF/TOF mass spectrograph. RESULTS: Compared to the sham operation group, the expressions of 4 proteins were up-regulated and that of 2 proteins were down-regulated in the model group. Six proteins were identified by ultraflex TOF/TOF, which were ubiquitin carboxy-terminal hydrolase L1; Dynamin-1; TMF regulated nuclear protein-like, partial; ATP synthase; rCG50513, isoform CRA_a; and expressed sequence AU016693, isoform CRA_b. CONCLUSION: Well-resolved and reproducible 2-DE patterns of chronic cerebral ischemia rats were established. Six proteins that correlate with nerve damage after chronic cerebral ischemia are identified.

[Effects of baicalin against oxidative stress injury of SH-SY5Y cells by up-regulating SIRT1].

This study is to investigate the effect of baicalin (BL) against oxidative injury stress of SH-SY5Y cells induced by H2O2 and the possible mechanism. SH-SY5Y cells were pre-incubated with baicalin (25, 50, and 100 micromol x L(-1)) for 12 h prior to exposure to H2O2 (150 micromol x L(-1)) for 24 h. The viability of SH-SY5Y cells was measured by MTT assay. The contents of LDH and NO were determined. The percentage of apoptotic cells was assessed by flow cytometry (FCM). The content of Caspase-3 was tested by immunofluorescence histochemical method. BL at 50 and 100 micromol x L(-1) separately increased the cell viability and up-regulated SIRT1, reduced the contents of LDH, NO, Caspase-3 and the apoptotic percentage of SH-SY5Y cells. This study results suggest that baicalin could inhibit the H2O2-induced neuronal apoptosis. The further mechanism studies show that baicalin inhibit apoptosis via reducing Caspase-3 expression and up-regulating SIRT1.

[Study on pancreas of type 1 diabetic mice induced by MLD-STZ using proteomics].

OBJECTIVE: To get a better understanding of the mechanisms underlying type 1 diabetes mellitus, the differentially expressed pancreatic proteins from multiple low-dose streptozotocin (MLD-SIZ) mouse and normal mouse were analyzed and compared. METHODS: 20 male rats were separated into 2 groups (n=10): model mice treated with MLD-STZ and normal mice,differences of pancreatic proteome among in the two groups of mice, were analyzed by two dimensional polyacryamide gel electrophoresis (2DE). Protein quantification was analyzed and the differentially expressed spots were identified using mass spectrometry and MASCOT database searching. RESULTS: Compared with control group, 23 proteins had changed significantly in the model group, 8 proteins expression were up-regulated, 15 proteins expressions down-regulated significantly. Using MALDI-TOF-MS, 15 proteins with significant change were identified by peptide fingerprinting map and the results were searched in MASCOT database. The function analyzed showed that proteins with change were associated with metabolic, anti-oxidant, structural, catalytic enzymes and chaperone, et al. CONCLUSION: Type 1 diabetes is probably exerted via multi-target and multi-path mechanism. The proteins with significant change are newly target for type 1 diabetes early diagnosis and treatment.

[Protective effect of extract of Apocynum venetum on kidneys of streptozotocin-induced diabetic rats].

The aim of this study is to investigate the effects and mechanism of extract of Apocynum venetum (AV) on kidneys of streptozotocin-induced diabetic rats. Diabetes mellitus (DM) was induced in rats by intraperitoneal injection of streptozotocin (STZ). The indexes of the blood glucose, renal function and oxidative stress were observed. The DM rats were administrated with the AV for 8 weeks, the above-mentioned indexes were detected. The blood glucose level, BUN, 24 h urine protein excretion, urine volume, renal index, renal cortex's MDA level in model groups all increased significantly. Renal cortex's SOD and GSH activities decreased significantly compared with the normal control group (P < 0.05). The above-mentioned indexes were significantly improved by the AV treatment (P < 0.05). AV have protective effects on renal function of kidneys of streptozotocin-induced diabetic rats, and maybe via inhibition of the renal oxidative stress.

[Effects of hyperin on the cccDNA of duck hepatitis B virus and its immunological regulation].

The aim of this study is to investigate the effect of hyperin on the cccDNA of duck hepatitis B virus and its immunological regulation. Duck hepatitis B virus (DHBV) infection model and normal mouse spleen lymphocyte were used to evaluate the anti-HBV and immunoregulation effects. The DHBV-DNA of serum was detected at different time points by using serum DOT-BLOT hybridization. Polymerase chain reaction (PCR) was used for the determination of nuclear covalent closed circular DNA (cccDNA). Cytokine secretion was determined by ELISA method. DHBV-DNA were inhibited by hyperin (25 or 50 mg x kg(-1)), while cccDNA of liver could be eliminated efficiently by hyperin (25 or 50 mg x kg(-1), P < 0.05, P < 0.01). The T helper 1 effector cytokine was markedly enhanced by hyperin (25 or 50 microg x mL(-1), P < 0.01). In conclusion, hyperin has anti-HBV activity via multiple targets and pathways, and cccDNA may be one of the important targets.

Effective induction of antitumor immunity by immunization with plasmid DNA encoding TRP-2 plus neutralization of TGF-beta.

Plasmid DNA vaccine is an appealing cancer immunotherapy. However, it is a weak immunogen and immunization with plasmid DNA encoding self-antigens, such as melanoma-associated antigens, could not induce antitumor immunity because of tolerance. In this study, we investigated the feasibility of using a plasmid DNA encoding Xenopus laevis transforming growth factor-beta 5 (aTGF-beta5) as an immunogen to induce neutralizing antibodies against murine TGF-beta1 (mTGF-beta1) and thus enhance the efficacy of plasmid DNA vaccine encoding murine tyrosinase-related protein 2 (mTRP-2) through neutralization of TGF-beta. The results showed that immunization with aTGF-beta5 resulted in the generation of mTGF-beta1-neutralizing antibodies, and immunization with a combination of aTGF-beta5 and mTRP-2 induced specific cytotoxic T lymphocytes (CTLs). On the contrary, immunization with mTRP-2 alone could not elicit the CTL response. Moreover, immunization of C57BL/6 wild-type mice with a combination of aTGF-beta5 and mTRP-2 induced the protective and therapeutic antitumor immunity to B16F10 melanoma, whereas the antitumor activity was abrogated in both CD4-deficient mice and CD8-deficient mice on the C57BL/6 background. Our results indicate that immunization with aTGF-beta5 is capable of breaking immune tolerance and induces mTGF-beta1-neutralizing antibodies. Neutralization of TGF-beta can enhance the efficacy of DNA vaccine encoding mTRP-2 and the induction of antitumor immunity by this immunization strategy is associated with CD4+ and CD8+ T cells.

MHC class I-associated presentation of exogenous peptides is not only enhanced but also prolonged by linking with a C-terminal Lys-Asp-Glu-Leu endoplasmic reticulum retrieval signal.

Vaccination with antigenic peptide-pulsed antigen-presenting cells (APC) represents an attractive approach for therapy for cancer and diseases caused by intracellular infections. It has been suggested that sufficient stable MHC/peptide complexes on the surface of APC might play an important role in the generation of antitumor and antiviral immunity in vivo. In this study, we observed that exogenous peptides that were artificially fused with an endoplasmic reticulum (ER) retrieval signal, a C-terminal Lys-Asp-Glu-Leu sequence, could be efficiently presented by intracellular MHC class I molecules in a TAP- and proteasome-independent, but brefeldin A-sensitive manner. The APC retained the capacity to display surface MHC/peptide complexes for a prolonged period. In addition, our results show that vaccination with DC bearing our fusion peptides induced greatly enhanced specific CTL response, and resulted in significant inhibition of tumor growth. Thus, the ER retrieval signal modification can be regarded as a novel method for targeting exogenous peptides into the intracellular MHC class I presentation pathway, and may improve the clinical utility of vaccines based on synthetic peptide pulsed DC.

Oral immunization with rotavirus VP7 expressed in transgenic potatoes induced high titers of mucosal neutralizing IgA.

Rotaviruses (RV) are a common cause of severe diarrhea in young children, resulting in nearly one million deaths worldwide annually. Rotavirus VP7 was the rotavirus neutralizing protein. Previous study reported that VP7 DNA vaccine can induce high levels of IgG in mice but cannot protect mice against challenge (Choi, A.H., Basu, M., Rae, M.N., McNeal, M.M., Ward, R.L., 1998. Virology 250, 230-240). We found that rotavirus VP7 could maintain its neutralizing immunity when it was transformed into the potato genome. Mice immunized with the transformed tubers successfully elicited serum IgG and mucosal IgA specific for VP7. The mucosal IgA titer was as high as 1000, while serum IgG titer was only 600. Neutralizing assays indicated that IgA could neutralize rotavirus. These results indicate the potential usefulness of plants for production and delivery of edible rotavirus vaccines.

Preparation of collagen-based materials for wound dressing.

OBJECTIVE: To describe the methods which were used to develop collagen-based materials for wound dressing. METHODS: Fresh frozen bovine tendon was treated with 0.05 mol/L acetic acid at pH 3.2 for 48-72 hours, homogenized, filtered, mixed with 8% chondroitin sulphate, for creating a deaerated 1.5%-2.5% collagen solution. The solution was lyophilized in either a pre-frozen or non-pre-frozen mould. The collagen sponge was then cross-linked with 0.25% glutaraldehyde for 24 hours. Three other types of wound dressings were developed using a similar method: collagen membrane with a polyurethane membrane onlay, polyurethane-coated collagen membrane and collagen membrane on gauze. RESULTS: It was demonstrated that the use of frozen bovine tendon was stable, and that the prepared collagen sponge contained pores of 50-400 microm in diameter. CONCLUSIONS: Collagen could be used as wound dressing.

[Study on combined implantation of pig dermis and autologous skin in rats].

In this study the treatment effect of combined implantation of autologous skin on pig dermis in injured rats was observed. Twenty-one Wistar rats were used, and the wounds were formed by excising a piece of full thickness skin on the back. After the pig dermis was implanted, the autologous skin was grafted on the dermis at 0.7 and 10 days. In the group with perforated pig dermis, the autograft skin was implanted on the day when the pig dermis was implanted. The healing effect was evaluated by measuring wound area, and by observing the growth of the autograft skin. Two weeks after the autograft skin was implanted, the skin securely adhered to the dermis, and the edge of autograft skin expanded clearly. The wound of the autograft skin implanted in the perforation of the dermis healed completely after 3 weeks, but the other 3 groups had remnant small wound. The autograft skin merged with the dermis and its surrounding tissue, but a clear dividing line still existed between autograft skin and dermis after implantation. The area of the implanted dermis and autograft skin varied from 51.8% to 65.9% compared to its original size. The results suggested that the time and the way of autologous skin grafting on xenogenous dermis may influence wound contraction and healing time.