Inhibiting von Hippel‒Lindau protein-mediated Dishevelled ubiquitination protects against experimental parkinsonism.

Dopaminergic neuron degeneration is a hallmark of Parkinson's disease (PD). We previously reported that the inactivation of von Hippel‒Lindau (VHL) alleviated dopaminergic neuron degeneration in a C. elegans model. In this study, we investigated the specific effects of VHL loss and the underlying mechanisms in mammalian PD models. For in vivo genetic inhibition of VHL, AAV-Vhl-shRNA was injected into mouse lateral ventricles. Thirty days later, the mice received MPTP for 5 days to induce PD. Behavioral experiments were conducted on D1, D3, D7, D14 and D21 after the last injection, and the mice were sacrificed on D22. We showed that knockdown of VHL in mice significantly alleviated PD-like syndromes detected in behavioral and biochemical assays. Inhibiting VHL exerted similar protective effects in MPP+-treated differentiated SH-SY5Y cells and the MPP+-induced C. elegans PD model. We further demonstrated that VHL loss-induced protection against experimental parkinsonism was independent of hypoxia-inducible factor and identified the Dishevelled-2 (DVL-2)/ß-catenin axis as the target of VHL, which was evolutionarily conserved in both C. elegans and mammals. Inhibiting the function of VHL promoted the stability of ß-catenin by reducing the ubiquitination and degradation of DVL-2. Thus, in vivo overexpression of DVL-2, mimicking VHL inactivation, protected against PD. We designed a competing peptide, Tat-DDF-2, to inhibit the interaction between VHL and DVL-2, which exhibited pharmacological potential for protection against PD in vitro and in vivo. We propose the therapeutic potential of targeting the interaction between VHL and DVL-2, which may represent a strategy to alleviate neurodegeneration associated with PD.

The novel α-glucan YCP improves the survival rates and symptoms in septic mice by regulating myeloid-derived suppressor cells.

Sepsis is a life-threatening health condition that is initially characterized by uncontrolled inflammation, followed by the development of persistent immunosuppression. YCP is a novel α-glucan purified from the mycelium of the marine fungus Phoma herbarum YS4108, which has displayed strong antitumor activity via enhancing host immune responses. In this study, we investigated whether YCP could influence the development of sepsis in a mouse model. Caecal ligation and puncture (CLP)-induced sepsis was established in mice that were treated with YCP (20 mg/kg, ip or iv) 2 h before, 4 and 24 h after the CLP procedure, and then every other day. YCP administration greatly improved the survival rate (from 39% to 72% on d 10 post-CLP) and ameliorated disease symptoms in the septic mice. Furthermore, YCP administration significantly decreased the percentage of myeloid-derived suppressor cells (MDSCs) in the lungs and livers, which were dramatically elevated during sepsis. In cultured BM-derived cells, addition of YCP (30, 100 µg/mL) significantly decreased the expansion of MDSCs; YCP dose-dependently decreased the phosphorylation of STAT3 and increased the expression of interferon regulatory factor-8 (IRF-8). When BM-derived MDSCs were co-cultured with T cells, YCP dose-dependently increased the production of arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS), and activated the NF-κB pathway. In addition, the effects of YCP on MDSCs appeared to be dependent on toll-like receptor (TLR) 4. These results reveal that YCP inhibits the expansion of MDSCs via STAT3 while enhancing their immunosuppressive function, partially through NF-κB. Our findings suggest that YCP protects mice against sepsis by regulating MDSCs. Thus, YCP may be a potential therapeutic agent for sepsis.

Exendin-4 ameliorates oxidized-LDL-induced inhibition of macrophage migration in vitro via the NF-κB pathway.

AIM: To investigate the effects of the glucagon-like peptide-1 (GLP-1) receptor agonist exendin-4 on oxidized low-density lipoprotein (ox-LDL)-induced inhibition of macrophage migration and the mechanisms underlying the effects of exendin-4. METHODS: Primary peritoneal macrophages were extracted from the peritoneal cavity of mice treated with 3% thioglycollate (2 mL, ip). Migration of the macrophages was examined using a cell migration assay. Macrophage migration-related factors including leptin-like ox-LDL receptor (LOX-1), cyclooxygenase 2 (COX-2), tumor necrosis factor (TNF)-α, interleukin-1 (IL-1)ß, matrix metalloproteinase-2 (MMP-2), intercellular adhesion molecule (ICAM)-1 and macrophage migration inhibitory factor (MIF) were measured using semi-quantitative RT-PCR. Expression of MIF and ICAM-1 proteins was examined with ELISA. Gelatin zymography was used to evaluate the activity of MMP-9. Activation of the NF-κB pathway was determined by confocal laser scanning microscopy. RESULTS: Treatment of the macrophages with ox-LDL (50 µg/mL) markedly suppressed the macrophage migration. Furthermore, ox-LDL treatment substantially increased the expression of the macrophage migration-related factors, the activity of MMP-9 and the translocation of the NF-κB p65 subunit. These effects of ox-LDL were significantly ameliorated by pretreatment with the specific NF-κB inhibitor ammonium pyrrolidine dithiocarbamate (100 µmol/L). These effects of ox-LDL were also significantly ameliorated by pretreatment with exendin-4 (25 and 50 nmol/L). CONCLUSION: Exendin-4 ameliorates the inhibition of ox-LDL on macrophage migration in vitro, via suppressing ox-LDL-induced expression of ICAM-1 and MIF, which is probably mediated by the NF-κB pathway.

A peptide rich in glycine-serine-alanine repeats ameliorates Alzheimer-type neurodegeneration.

BACKGROUND AND PURPOSE: Repeated amino acid sequences in proteins are widely found, and the glycine-serine-alanine repeat is an element with a general propensity to form ß-sheet aggregates as found in key pathological factors, in several neurodegenerative diseases. Such properties of this repeat may guide development of disease-modifying therapies for neurodegenerative disease. However, details of its role and underlying mechanism(s) remain largely unknown. EXPERIMENTAL APPROACH: Actions of specific glycine-serine-alanine repeat peptides (SNPs), especially SNP-9, on Alzheimer's disease (AD)-like abnormalities were evaluated in transgenic mice and Caenorhabditis elegans, and in rat and cell models. Entry of SNPs into the brain, SNP activity in neuronal cells and peptide entry into cells were analysed in vivo and in vitro. Cell-free systems and the yeast two-hybrid system were also used to explore possible targets of SNP-9, and interactions of potential targets with SNP-9 were confirmed in cell-based systems. KEY RESULTS: We first identified SNP-9 as a potent neuroprotective peptide with the activity to decrease oligomeric amyloid ß (Aß) via co-assembling with the toxic Aß oligomer to form hetero-oligomers. Also, calcyclin-binding protein was found to act as a SNP-9-binding protein, by screening of a human brain cDNA library. Such binding showed that SNP-9 could regulate the abnormal hyperphosphorylation of tau via calcyclin-binding protein. CONCLUSION AND IMPLICATIONS: Our study provides a foundation for development of SNPs, especially SNP-9, as potential therapeutic interventions for AD. We propose SNP-9 as a potential therapeutic agent for the treatment of AD.

[Expression and pharmacological evaluation of fusion protein FGF21-L-Fc].

FGF21 (fibroblast growth factor 21) is a recently described member of the FGF family. It has been previously demonstrated that FGF21 is a potent regulator of glucose homeostasis. To improve stability of FGF21 for better efficacy, a new form of recombinant FGF21 was generated by fusion of a full length FGF21 gene and the Fc fragment of human IgG4 with flexible linker sequence. To examine the glucose regulation activity of FGF21-L-Fc, 3T3-L1 pre-adipocytes were differentiated into adipocytes, and glucose uptake activity of FGF21-L-Fc was examined by glucose oxidase and peroxidase (GOD-POD) assay. The results showed that in comparison with wild type FGF21, FGF21-L-Fc was more potent in stimulation of glucose uptake by 3T3-L1. In vivo studies on the modified protein demonstrated that FGF-L-Fc had a better efficacy in lowering blood glucose of the STZ-induced diabetic animals and controlled glucose level for a longer time. The results provided a sound basis for further studies.

Regulation of RDN on Th1/ILC1 cell imbalance in HFMD patients caused by EV71 infection.

Enterovirus 71 (EV71) infection is more likely to cause hand, foot and mouth disease (HFMD) in children, which can lead to neurogenic complications and higher mortality. As a commonly used clinical medicine, Reduning injection (RDN) helps to shorten the symptoms of patients with HFMD and facilitate the early recovery of children. However, the regulatory mechanism of RDN on the HFMD immune system disorder caused by EV71 remains to be discussed. This study collected detailed treatment data of 56 children with HFMD who entered the affiliated Children's Hospital of Nanjing Medical University during 2019. Retrospective analysis of clinical data showed that the symptoms of the RDN treatment group were improved compared with the untreated group. To explore its mechanism, the relevant detection indicators were detected by flow cytometry, enzyme-linked immunosorbent assay and real-time quantitative PCR. It was found that the number and function of innate immune (ILCs) and adaptive immunity (Th1, Th2 and secreted cytokines) were reduced, suggesting that RDN plays a role by regulating cellular immunity. The in vitro differentiation inhibition test further confirmed that RDN affected Th1 differentiation by inhibiting the expression of transcription factors on the basis of Th1 cell differentiation in vitro.

Modulation of the Astrocyte-Neuron Lactate Shuttle System contributes to Neuroprotective action of Fibroblast Growth Factor 21.

A viewpoint considering Alzheimer's disease (AD) as "type 3 diabetes" emphasizes the pivotal role of dysfunctional brain energy metabolism in AD. The hormone fibroblast growth factor 21 (FGF21) is a crucial regulator in energy metabolism; however, our understanding of the therapeutic potential and mechanisms underlying the effect of FGF21 on neurodegeneration of AD is far from complete. Methods: To further elucidate the effect of FGF21 on AD-related neurodegeneration, we used APP/PS1 transgenic mice to assess the effects of FGF21 on memory dysfunction, amyloid plaque pathology and pathological tau hyperphosphorylation. We also established an in vitro system to mimic astrocyte-neuron communication and an in vivo model of acute injury. Based on the in vivo and in vitro models, we analyzed the neuroprotective actions of FGF21 and pathways related to astrocyte-neuron communication and further focused on the astrocyte-neuron lactate shuttle system. Results: Here, we report that FGF21 can ameliorate Alzheimer-like neurodegeneration in APP/PS1 transgenic mice. We detected defects in the astrocyte-neuron lactate shuttle system in the in vivo and in vitro models of AD and identified FGF21 as a neuroprotective molecule that can rescue these deficits. Administration of FGF21 can alleviate memory dysfunction, amyloid plaque pathology and pathological tau hyperphosphorylation, and the function of FGF21 in neurodegeneration is mediated in part by monocarboxylate transporters (MCTs). In vivo evidence also suggests that FGF21 acts centrally in mice to exert its effects on neurodegeneration and energy metabolism via its regulation of MCTs. Conclusions: These results suggest that FGF21 alters metabolic parameters to mediate its neuroprotective functions. Modulation of the astrocyte-neuron lactate shuttle system can be one of the most efficient strategies for FGF21 in Alzheimer-like degeneration and contributes to improvements in brain metabolic defects and amyloid ß-induced cytotoxicity. Our findings provide insights into the mechanisms underlying the effects of FGF21 on neurodegeneration and brain energy metabolism and suggest that FGF21 may have therapeutic value in the treatment of AD and other neurodegenerative diseases.

Macrophage receptors of polysaccharide isolated from a marine filamentous fungus Phoma herbarum YS4108.

AIM: YCP, a novel (1,4)-alpha-D-glucan, was isolated from the mycelium of the marine filamentous fungus Phoma herbarum YS4108. In this work, we investigated a YCP-binding cellular receptor expressed by macrophages and the intracellular signal transduction pathways involved in YCP-induced macrophage activation. METHODS: Fluorescence-labeled YCP (fl-YCP) was prepared using the CDAP-activation method. Fluorescence confocal laser microscopy and fluorescence-activated cell sorting (FACS) were used to analyze the effect of fl-YCP on macrophages. To characterize the properties of the YCP receptor, carbohydrates and antibodies were used to inhibit the binding of fl-YCP to macrophages. Moreover, we investigated the role of membrane receptors Toll-like receptor 2 (TLR2), Toll-like receptor 4 (TLR4), Toll-like receptor 6 (TLR6) and complement receptor 3 (CR3). We also examined the role of the p38 kinase pathway in mediating nitric oxide (NO) production. RESULTS: YCP had an in vitro stimulatory effect on the release of NO in macrophage, and fl-YCP can bind directly to receptors on the surface of macrophages in a time- and dose-dependent manner. Competition studies show that LPS, laminarin, anti-TLR4 antibody and anti-CD11b (CR3) antibody could inhibit fl-YCP binding to macrophages. Conversely, mannose, anti-TLR2 and anti-TLR6 antibody could not. Treatment of RAW264.7 cells with YCP resulted in significant activation of p38 in a time-dependent manner. The specific p38 inhibitor SB203580 abrogated YCP-induced NO generation. Treatment of RAW264.7 cells with anti-TLR4 antibody and anti-CR3 antibody significantly reduced YCP-induced NO production and p38 activation. CONCLUSION: We have demonstrated that YCP-induced NO production occurs through the TLR4 and CR3 membrane receptors in a p38 kinase-dependent manner in macrophages.Acta Pharmacologica Sinica (2009) 30: 1008-1014; doi: 10.1038/aps.2009.93.

Quantitative determination of pegylated consensus interferon in rhesus monkey serum using a competitive enzyme-linked immunosorbent assay.

A competitive enzyme-linked immunosorbent assay (ELISA) with generated mouse anti-consensus interferon (CIFN) antibody was developed for quantitative determination of pegylated consensus interferon (PEG-CIFN) in rhesus monkey serum. The operational concentrations of the original assay were determined using the chessboard method. ELISA working range was 10-5000 ng/ml, corresponding to a limit of quantification of 8.4 ng/ml in rhesus monkey serum. In a precision test, intra-assay CV ranged 1.8-9.6% and inter-assay CV ranged 3.5-12.7%. Relative recovery rate of this ELISA assay ranged from 102.65-115.77%, with RSD values ranging from 2.26-5.44%. Three groups of rhesus monkeys received 1250 microg/kg, 300 microg/kg, 150 microg/kg PEG-CIFN by subcutaneous administration, and blood samples were drawn via the femoral vein at the specified time points. PEG-CIFN in rhesus monkey serum was determined using the competitive ELISA, and the results were compared with antiviral activity assay. In conclusion, the competitive ELISA assay we developed has sufficient sensitivity, precision, and accuracy for the analysis of a rhesus monkey serum sample.

Fibroblast growth factor 21 ameliorates neurodegeneration in rat and cellular models of Alzheimer's disease.

Our understanding of the mechanisms underlying process in Alzheimer's disease (AD) is far from completion and new therapeutic targets are urgently needed. Recently, the link between dementia and diabetes mellitus (DM) prompted us to search for new therapeutic strategies from glucose metabolism regulators for neurodegeneration. Previous studies have indicated that fibroblast growth factor 21 (FGF21), an attractive and potential therapeutic treatment for DM, may exert diverse effects in the central nervous system. However, the specific biological function and mechanisms of FGF21 on AD is still largely unknown. We report here a study in vivo and in vitro of the neuroprotective effects of FGF21 on cell apoptosis, tau hyperphosphorylation and oxidative stress induced by amyloid ß-peptide 25-35. In the present study, the results also further provided evidence for molecular mechanisms by which FGF21 exerted its beneficial effects in neuron and suggested that the regulation of protein phosphatase 2A / mitogen-activated protein kinases / hypoxia-inducible factor-1α pathway may play a key role in mediating the neuroprotective effects of FGF21 against AD-like pathologies.

Evidence of metabolic memory-induced neurodegeneration and the therapeutic effects of glucagon-like peptide-1 receptor agonists via Forkhead box class O.

Metabolic memory, which refers to diabetic stresses that persist after glucose normalization, is considered a major factor in addition to hyperglycaemia for diabetes complications, including dementia. We previously reported that glucagon-like peptide-1 receptor agonist (GLP-1RA) alleviated neuronal injury in diabetes-related dementia models. However, our understanding of the effects and mechanisms of GLP-1RA on metabolic memory-induced neurodegeneration are limited. The present study mainly focuses on the mechanisms of action of GLP-1RA on metabolic memory-induced neurotoxicity in vivo and in vitro. Thus, in this study, aiming at mimicking metabolic memory phenomena, in vivo and in vitro models were exposed to high glucose first and then normal glucose. We also used advanced glycation end products, which are key metabolic memory-related factors, to induce neuronal injury in vitro. Based on the models, here, we report that GLP-1RA alleviated neurodegeneration in db/db mice with normalized blood glucose levels controlled with metformin and neuronal damage induced by high glucose treatment followed by withdrawal. GLP-1RA ameliorated metabolic memory-induced amyloid-ß and tau pathologies in vivo and in vitro. Furthermore, the data suggested that GLP-1RA can protect neurons against metabolic memory via Forkhead box class O (FoxO) pathways, and silent information regulator 2 homolog 1-dependent deacetylation and protein kinase B-dependent phosphorylation of FoxO1 were involved in the mechanisms underlying protective effects. This study provides evidence of the beneficial effects of GLP-1RA on neuronal cell metabolic memory, as well as GLP-1 analogues and metformin combination therapy efficiency on cognitive impairment.

Pharmacokinetic properties of a 40 kDa branched polyethylene glycol-modified form of consensus interferon-alpha (PEG-CIFN) in rhesus monkeys.

The pharmacokinetic properties of a branched 40 kDa polyethylene glycol (PEG) conjugate formulation of consensus interferon-alpha (CIFN) was evaluated in rhesus monkeys following subcutaneous administration. Four groups of rhesus monkeys (n=6 per group) received 1250, 300 and 150 microg/kg of PEG-CIFN and 150 microg/kg CIFN, respectively. Serum concentrations of the interferons were measured with an antiviral activity assay at various time points after administration. The PK profiles of the pooled data were described by a noncompartmental method. Peak concentration of PEG-CIFN was observed at 27-31 h, followed by a prolonged decay in comparison with the unmodified CIFN, the PEG-CIFN had a 4-5-fold longer terminal half-life. The apparent clearance (dose(sc)/AUC) decreased from 150 mL/h/kg for CIFN to 19.0-45.5 mL/h/kg for PEG-CIFNs. The AUC was lower for PEG-CIFN than that for CIFN at the 150 microg/kg.

Establishment of a fluorescence-based method to evaluate endocytosis of desialylated glycoproteins in vitro.

Insufficient sialylation can result in rapid clearance of therapeutic glycoproteins by intracellular degradation, which is mainly mediated by asialoglycoprotein receptors (ASGPRs) on hepatic cells. In contrast, for glycoproteins, a long half-life is often related to high level of terminal sialic acid. These could be extremely important for insufficient sialylated biomedicines in clinic, and development of therapeutic glycoproteins in laboratory. However, how the desialylated glycoproteins are removed and how to evaluate the ASGPRs mediated endocytosis in vitro needs further investigate. Herein we described an integrative characterization of ASGPRs in vitro to elucidate its endocytosis properties. The endocytosis was determined by a fluorescence-based quantization method. The results showed that the ASGPRs could bind to poorly sialylated glycoproteins including asialofetuin and low sialylated recombinant Factor VIIa with a relatively higher ASGPRs binding affinity, and induce a more rapid endocytosis in vitro. Moreover, the mechanism under the internalization of ASGPRs was also investigated, which was found to depend on clathrin and caveolin. Utilizing the relative fluorescence quantification can be suitable for measurement of insufficient sialylated glycoprotein endocytosis and quality control of therapeutic glycoproteins, which could be useful for the understanding of the development of therapeutic glycoproteins.

Glycoengineering of pertuzumab and its impact on the pharmacokinetic/pharmacodynamic properties.

Pertuzumab is an antihuman HER2 antibody developed for HER2 positive breast cancer. Glycosylation profiles are always the important issue for antibody based therapy. Previous findings have suggested the impact of glycosylation profiles on the function of antibodies, like pharmacodynamics, antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). However, the roles of fucose and sialic acid in the function of therapeutic antibodies still need further investigation, especially the role of sialic acid in nonfucosylated antibodies. This study focused on the pharmacokinetic and pharmacodynamic properties of pertuzumab after glycoengineering. Herein, nonfucosylated pertuzumab was produced in CHOFUT8-/- cells, and desialylated pertuzumab was generated by enzymatic hydrolysis. Present data indicated that fucose was critical for ADCC activity by influencing the interaction between pertuzumab and FcγRIIIa, nevertheless removal of sialic acid increased the ADCC and CDC activity of pertuzumab. Meanwhile, regarding to sialic acid, sialidase hydrolysis directly resulted in asialoglycoprotein receptors (ASGPRs) dependent clearance in hepatic cells in vitro. The pharmacokinetic assay revealed that co-injection of asialofetuin can protect desialylated pertuzumab against ASGPRs-mediated clearance. Taken together, the present study elucidated the importance of fucose and sialic acid for pertuzumab, and also provided further understanding of the relationship of glycosylation/pharmacokinetics/pharmacodynamics of therapeutic antibody.

Inhibiting receptor for advanced glycation end product (AGE) and oxidative stress involved in the protective effect mediated by glucagon-like peptide-1 receptor on AGE induced neuronal apoptosis.

Our previous study has demonstrated that glucagon-like peptide-1 (GLP-1) receptor agonist could protect neurons from advanced glycation end products (AGEs) toxicity in vitro. However, further studies are still needed to clarify the molecular mechanism of this GLP-1 receptor -dependent action. The present study mainly focused on the effect of GLP-1 receptor agonists against the receptor for advanced glycation end products (RAGE) signal pathway and the mechanism underlying this effect of GLP-1. Firstly the data based on the SH-GLP-1R(+) and SH-SY5Y cells confirmed our previous finding that GLP-1 receptor could mediate the protective effect against AGEs. The assays of the protein activity and of the mRNA level revealed that apoptosis-related proteins such as caspase-3, caspase-9, Bax and Bcl-2 were involved. Additionally, we found that both GLP-1 and exendin-4 could reduce AGEs-induced reactive oxygen species (ROS) accumulation by suppressing the activity of nicotinamide adenine dinucleotide phosphate-oxidase. Interestingly, we also found that GLP-1 receptor activation could attenuate the abnormal expression of the RAGE in vitro and in vivo. Furthermore, based on the analysis of the protein expression and translocation level of transcription factor nuclear factor-κB (NF-κB), and the use of GLP-1 receptor antagonist exendin(9-39) and NF-κB inhibitor pyrrolidine dithiocarbamate, we found that the effect mediated by GLP-1 receptor could alleviate the over expression of RAGE induced by ligand via the suppression of NF-κB. In summary, the results indicated that inhibiting RAGE/oxidative stress was involved in the protective effect of GLP-1 on neuron cells against AGEs induced apoptosis.

Preparation, optimization and application of affinity absorbent with a polysaccharide YCP as the ligand.

YCP, an α-glucan from the mycelium of marine filamentous fungus Phoma herbarum YS4108, has great antitumor potential via enhancement of host immune through Toll-like receptor (TLR) 2 and TLR4 signaling. In the current study, YCP was coupled to EAH Sepharose 4B agarose beads to prepare the YCP-Sepharose affinity absorbent using 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) as the activating agent. An orthogonal experiment L9 (3)(4) was applied to optimize the coupling procedure, giving the optimal parameters as follows: molar ratio of CDAP to YCP of 1:2, CDAP-activation time of 5 min, gel volume of 0.1 mL, and gel-incubation time of 72 h, respectively. Scanning electron microscopy analysis indicated successfully preparation of YCP immobilized sepharose beads, while these beads essentially maintained biological properties of free YCP since they can interact with TLR2 and TLR4 specifically at comparable level. Collectively, our findings provide an alternative approach to immobilize carbohydrate-based molecules for studying the carbohydrate-protein interaction.

Suppression of human and mouse Th17 differentiation and autoimmunity by an endogenous Interleukin 23 receptor cytokine-binding homology region.

T-helper 17 (Th17) cells, a recently identified CD4+ T subset with a unique characteristic to produce Interleukin-17 (IL-17), are critical for the development of autoimmune diseases such as multiple sclerosis, in which IL-23 plays an important role in the differentiation of Th17 cells through IL-23/IL-23-receptor/STAT3 pathway. Previously, soluble recombinant human IL-23 receptor cytokine-binding homology region (hIL23R-CHR) was constructed in our laboratory to neutralize IL-23 and inhibit murine Th17 development in vitro. Herein we present that hIL23R-CHR could inhibit both differentiation and function of human/murine Th17 cells. The present in vivo study further demonstrated that hIL23R-CHR inhibited murine Th17 cell development by down regulating IL-17 gene expression and protected mice against the development of experimental autoimmune encephalomyelitis (EAE) through suppression of CNS inflammation and pro-inflammatory cytokine production. In addition to the in vitro inhibition of human Th17 cells in a dose-dependent manner, the antagonizing effect of hIL23R-CHR was confirmed by reduced levels of IL-23 in both blood and brain of EAE mice and STAT3 phosphorylation in vivo. Taken together, our data demonstrated that hIL23R-CHR could be an effective and specific immunosuppressive molecule for the treatment of Th17-related autoimmune diseases.

Amelioration of neurodegenerative changes in cellular and rat models of diabetes-related Alzheimer's disease by exendin-4.

Growing evidence suggests that type 2 diabetes mellitus (DM) is associated with age-dependent Alzheimer's disease (AD), the latter of which has even been considered as type 3 diabetes. Several physiopathological features including hyperglycemia, oxidative stress, and dysfunctional insulin signaling relate DM to AD. In this study, high glucose-, oxidative stress-induced neuronal injury and intracerebroventricular-streptozotocin (ICV-STZ) animals as the possible models for diabetes-related AD were employed to investigate the effects of exendin-4 (Ex-4), a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist, on diabetes-associated Alzheimer-like changes as well as the molecular mechanisms involved. Our study demonstrated that GLP-1/Ex-4 could exert a protective effect against reduced viability of PC12 cells caused by high glucose and that this protective effect was mediated via the PI3-kinase pathway. In addition, GLP-1/Ex-4 ameliorated oxidative stress-induced injury in PC12 cells. In rat models, bilateral ICV-STZ administration was used to produce impaired insulin signaling in the brain. Fourteen days following ICV-STZ injection, rats treated with twice-daily Ex-4 had better learning and memory performance in the Morris water maze test compared with rats treated with saline. Additionally, histopathological evaluation confirmed the protective effects of Ex-4 treatment on hippocampal neurons against degeneration. Furthermore, we demonstrated that Ex-4 reversed ICV-STZ-induced tau hyperphosphorylation through downregulation of GSK-3ß activity, a key kinase in both DM and AD. Our findings suggests that Ex-4 can protect neurons from diabetes-associated glucose metabolic dysregulation insults in vitro and from ICV-STZ insult in vivo, and that Ex-4 may prove of therapeutic value in the treatment of AD especially DM-related AD.

Aqueous extract of the Chinese medicine, Danggui-Shaoyao-San, inhibits apoptosis in hydrogen peroxide-induced PC12 cells by preventing cytochrome c release and inactivating of caspase cascade.

Danggui-Shaoyao-San (DSS), a traditional Chinese medicine used for centuries for the enhancement of women's health, has been shown to display therapeutic efficacy on senile dementia. In the present study, using a rat pheochromocytoma (PC12) cell line, the effect of DSS on hydrogen peroxide (H2O2) induced apoptosis was studied. The apoptosis in H2O2-induced PC12 cells was accompanied by downregulation of Bcl-2, upregulation of Bax, the release of mitochondrial cytochrome c into cytosol, and sequential activation of caspase-9 and -3. DSS was able to suppress all these changes and eventually protected against H2O2-induced apoptosis. Taken together, these results suggest that treatment of PC12 cells with DSS can block H2O2-induced apoptosis by the regulation of Bcl-2 family members, as well as suppression of cytochrome c release and caspase cascade activation.