The chemical warfare agent sulfur mustard (SM) causes severe cutaneous lesions characterized by epidermal cell death, apoptosis, and inflammation. At present, the molecular mechanisms underlying SM-induced injury are not well understood, and there is no standard treatment protocol for SM-exposed patients. Here, we conducted a high-content screening of the Food and Drug Administration (FDA)-approved drug library of 1018 compounds against SM injury on an immortal human keratinocyte HaCaT cell line, focusing on cell survival. We found that the B-Raf inhibitor vemurafenib had an apparent therapeutic effect on HaCaT cells and resisted SM toxicity. Other tested B-Raf inhibitors, both type-I (dabrafenib and encorafenib) and type-II (RAF265 and AZ628), also exhibited potent therapeutic effects on SM-exposed HaCaT cells. Both SM and vemurafenib triggered extracellular signal-related kinase (ERK) activation. The therapeutic effect of vemurafenib in HaCaT cells during SM injury was ERK-dependent, indicating a specific role of ERK in keratinocyte regulatory mechanisms. Furthermore, vemurafenib partially improved cutaneous damage in a mouse ear vesicant model. Collectively, our results provide evidence that the B-Raf inhibitor vemurafenib is a potential therapeutic agent against SM injury, and oncogenic B-Raf might be an exciting new therapeutic target following exposure to mustard vesicating agents.
目的 构建多腺苷二磷酸核糖聚合酶1(PARP-1)短发夹RNA(shRNA)的慢病毒载体质粒,获取稳定敲降PARP-1蛋白的人永生化表皮角化形成细胞HaCaT(PARP-1 KD HaCaT细胞).方法 针对PARP-1 mRNA设计干扰序列shRNA,用限制性内切酶技术将干扰序列shRNA插入慢病毒载体质粒pLVX-shRNA2-puro,构建含PARP-1 shRNA的慢病毒载体质粒(pLVX-shRNA2-puro-PARP-1),酶切和核酸测序鉴定该质粒是否构建成功.采用脂质体转染法将该质粒载体转染至HEK293T细胞包装慢病毒.将带有PARP-1 shRNA的慢病毒颗粒〔感染复数为100〕感染HaCaT细胞,经嘌呤霉素3 mg·L-1筛选15 d,用Western印迹法和实时定量PCR(RT-qPCR)检测PARP-1蛋白和mRNA表达水平,验证PARP-1 KD HaCaT细胞PAPR-1敲降效果.用相同方式构建阴性对照细胞(NC HaCaT细胞).随后分别将NC HaCaT和PARP-1 KD HaCaT细胞分为细胞对照组、DNA损伤剂硫芥(SM)100和1000μmol·L-1组,孵育6和24 h后制备细胞裂解液,用Luminex法测定磷酸化组蛋白H2AX(γ-H2AX)表达水平.结果 DNA测序和酶切结果表明,所构建的慢病毒载体质粒中含有PARP-1 shRNA序列,表明含PARP-1 shRNA的慢病毒载体质粒构建成功.RT-qPCR结果显示,PARP-1 KD HaCaT细胞中PARP-1 mRNA水平降低为NC HaCaT细胞的约14%;Western印迹法结果显示,PARP-1 KD HaCaT细胞中PARP-1蛋白表达水平降低为NC HaCaT细胞的约10%.DNA损伤剂SM 1000μmol·L-1作用24 h后,与NC HaCaT细胞相比,PARP-1 KD HaCaT细胞γ-H2AX表达水平明显增加(P<0.01).结论 成功构建含PARP-1 shRNA的慢病毒载体质粒,并获得稳定敲降PARP-1的HaCaT细胞.
OBJECTIVE To investigate the effect and mechanisms of Liuwei Dihuang Decoction(LW) on cognition in PrP-hAβPPswe/PS1ΔE9(APP/PS1) transgenic mice.METHODS LW was adminis.trated with oral for 3 months.The locomotor activity test was performed to investigate the spontaneous motor activity of mice.The Morris water maze test and shuttle box test were performed to investigate the spatial learning and memory and active avoidance response respectively.The Αβ deposits and neuron loss in the hippocampus was detected by immunofluorescence staining and nissl staining respectively.The flow cytometry was employed to investigate the lymphocyte subsets of the mice.The 3 H-thymidine incorporation was performed to investigate the splenocytes proliferation.RESULTS The treatment of LW ameliorated the impairments of spatial learning and memory and active and passive avoidance in APP/PS1 mice.The administration of LW alleviated neuron loss in the brain,suppressed amyloid-β(Αβ) deposits in the hippocampus of APP/PS1 mice.The treatment of LW significantly increased ConAand LPS-induced proliferation of splenocytes,increased CD3+ T cells and CD19+ B cells in the spleen lymphocytes and reduced Gr1+ cells in APP/PS1 mice.CONCLUSION This data indicated the adminis.tration of LW ameliorated behavioral and pathological deterioration via regulating immune function.
BACKGROUND:Alzheimer's disease (AD), the most common cause of dementia among older people, could not be prevented, halted, or reversed up till now. A large body of pharmacological study has revealed that Liuwei Dihuang decoction (LW), a classical traditional Chinese medicinal prescription, possesses potential therapeutic effects on AD. LW-AFC is key fractions from LW.METHOD:Cognition ability was evaluated by behavioral experiments. Using multiplex bead analysis, radioimmunoassay, immunochemiluminometry and ELISA to determine levels of cytokines and hormones. The splenocyte proliferation and peripheral lymphocyte subsets was investigated by 3H-thymidine incorporation and flow cytometric analysis, respectively.RESULTS:This study showed the treatment of LW-AFC slowed the aging process of senescence-accelerated mouse prone 8 strain (SAMP8), a robust model sporadic AD or late-onset/age-related AD. LW-AFC had ameliorative effects on spontaneous locomotor activity, object recognition memory, spatial learning and memory, passive and active avoidance impairment in SAMP8 mice. Administration of LW-AFC restored the imbalance of hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axis, enhanced the proliferation of splenocytes, corrected the disorder of lymphocyte subsets, and regulated the abnormal production of cytokine in SAMP8 mice. Effects of LW-AFC on pharmacodynamics and neuroendocrine immunomodulation network in SAMP8 mice were better than memantine and donepezil.CONCLUSION:This data indicated LW-AFC may be a promising therapeutic medicine for AD.
Accumulating evidence implicates the neuroendocrine immunomodulation (NIM) network in the physiopathological mechanism of Alzheimer’s disease (AD). Notably, we previously revealed that the NIM network is dysregulated in the PrP-hAβPPswe/PS1ΔE9 (APP/PS1) transgenic mouse model of AD.
By taking compound 1 as a lead,a series of 5-cyclopropyl substituted cyclic acylguanidine compounds were designed and synthesized as BACE1 inhibitors,compound 4d exhibited 84-fold improved inhibition efficiency than lead compound 1.The diphenyl fragment at the P3 position and the substituents at the second phenyl ring were essential for the compounds to achieve improved inhibition efficiency.This SAR studies provides new insights into the design and synthesis of more promising BACE1 inhibitors for the potential treatment of AD.
Although there were considerable advances in the anti-aging medical field, it is short of therapeutic drug for anti-aging. Mounting evidence indicates that the immunosenescence is the key physiopathological mechanism of aging. This study showed the treatment of LW-AFC, an herbal medicine, decreased the grading score of senescence, increased weight, prolonged average life span and ameliorated spatial memory impairment in 12- and 24-month-old senescence accelerated mouse resistant 1 (SAMR1) strain. And these anti-aging effects of LW-AFC were more excellent than melatonin. The administration of LW-AFC enhanced ConA- and LPS-induced splenocyte proliferation in aged SAMR1 mice. The treatment of LW-AFC not only reversed the decreased the proportions of helper T cells, suppressor T cells and B cells, the increased regulatory T cells in the peripheral blood of old SAMR1 mice, but also could modulate the abnormal secretion of IL-1β, IL-2, IL-6, IL-17, IL-23, GM-CSF, IFN-γ, TNF-α, TNF-β, RANTES, eotaxin, MCP-1, IL-4, IL-5, IL-10 and G-CSF. These data indicated that LW-AFC reversed the immunosenescence status by restoring immunodeficiency and decreasing chronic inflammation and suggested LW-AFC may be an effective anti-aging agent.
Senescence-accelerated mouse prone 8 strain (SAMP8) and PrP-hAβPPswe/PS1ΔE9 (APP/PS1) mice are classic animal models of sporadic Alzheimer's disease and familial AD respectively. Our study showed that object recognition memory, spatial learning and memory, active and passive avoidance were deteriorated and neuroendocrine immunomodulation (NIM) network was imbalance in SAMP8 and APP/PS1 mice. SAMP8 and APP/PS1 mice had their own specific phenotype of cognition, neuroendocrine, immune and NIM molecular network. The endocrine hormone corticosterone, luteinizing hormone and follicle-stimulating hormone, chemotactic factor monocyte chemotactic protein-1, macrophage inflammatory protein-1β, regulated upon activation normal T cell expressed and secreted factor and eotaxin, pro-inflammatory factor interleukin-23, and the Th1 cell acting as cell immunity accounted for cognitive deficiencies in SAMP8 mice, while adrenocorticotropic hormone and gonadotropin-releasing hormone, colony stimulating factor granulocyte colony stimulating factor, and Th2 cell acting as humoral immunity in APP/PS1 mice. On the pathway level, chemokine signaling and T cell receptor signaling pathway played the key role in cognition impairments of two models, while cytokine-cytokine receptor interaction and natural killer cell mediated cytotoxicity were more important in cognitive deterioration of SAMP8 mice than APP/PS1 mice. This mechanisms of NIM network underlying cognitive impairment is significant for further understanding the pathogenesis of AD and can provide useful information for development of AD therapeutic drug.
Early studies with first-generation poly (ADP-ribose) polymerase (PARP) inhibitors have already indicated some therapeutic potential for sulfur mustard (SM) injuries. The available novel and more potential PARP inhibitors, which are undergoing clinical trials as drugs for cancer treatment, bring it back to the centre of interest. However, the role of PARP-1 in SM-induced injury is not fully understood. In this study, we selected a high potent specific PARP inhibitor ABT-888 as an example to investigate the effect of PARP inhibitor in SM injury. The results showed that in both the mouse ear vesicant model (MEVM) and HaCaT cell model, PARP inhibitor ABT-888 can reduce cell damage induced by severe SM injury. ABT-888 significantly reduced SM induced edema and epidermal necrosis in MEVM. In the HaCaT cell model, ABT-888 can reduce SM-induced NAD + /ATP depletion and apoptosis/necrosis. Then, we studied the mechanism of PARP-1 in SM injury by knockdown of PARP-1 in HaCaT cells. Knockdown of PARP-1 protected cell viability and downregulated the apoptosis checkpoints, including p-JNK, p-p53, Caspase 9, Caspase 8, c-PARP and Caspase 3 following SM-induced injury. Furthermore, the activation of AKT can inhibit autophagy via the regulation of mTOR. Our results showed that SM exposure could significantly inhibit the activation of Akt/mTOR pathway. Knockdown of PARP-1 reversed the SM-induced suppression of the Akt/mTOR pathway. In summary, the results of our study indicated that the protective effects of downregulation of PARP-1 in SM injury may be due to the regulation of apoptosis, necrosis, energy crisis and autophagy. However, it should be noticed that PARP inhibitor ABT-888 further enhanced the phosphorylation of H2AX (S139) after SM exposure, which indicated that we should be very careful in the application of PARP inhibitors in SM injury treatment because of the enhancement of DNA damage.
Based on the lead compounds 1 and 2, a series of novel BACE1 inhibitors were designed and synthesized,among which compound 9h exhibited a 60 fold improvement in potency over the lead compound 1. This represents a good lead for the discovery of more promising BACE1 inhibitors for the potential treatment of AD. The result also showed that the prop-2-yn-1-yloxy is a suitable fragment for modification of cyclic acylguanidine BACE1 inhibitors.
Based on the lead compound 1 reported in literature, a series of novel BACE1 inhibitors were designed and synthesized, among which compound 11 exhibited a 14-fold improvement in potency over the lead compound 1. This represents a good lead for the discovery of more promising BACE1 inhibitors for the potential treatment of AD.
Lycium barbarum L., known as wolfberry, is an important Chinese herbal medicine. In the research, we purified water-soluble polysaccharide-protein complex (LBPF4) and polysaccharide (LBPF4-OL) from the fruiting bodies of L. barbarum L. The monosaccharide and amino acid composition of LBPF4 and LBPF4-OL was elucidated with fractional acid hydrolization, GC/MC and NMR techniques. LBPF4-OL molecular weight was 181kDa, as determined by high-performance gel-permeation chromatography (HPGPC). In vitro assay, we found that LBPF4 induced splenocyte proliferations depended on both B cells and T cells, but LBPF4-OL induced splenocyte proliferations mainly depended on B cells. ELISA results showed that both LBPF4 and LBPF4-OL significantly induced TNF-α, IL-1β and NO production on macrophage. We also found that both LBPF4 and LBPF4-OL can enhance macrophage phagocytosis. Furthermore, electrophoretic mobility shift assay (EMSA) studies suggest that LBPF4 100μg/ml treatment can more effectively increase NF-κB activity than LBPF4-OL. Taken together, our results demonstrate that LBPF4 can enhance T, B cells and macrophages functions, but LBPF4-OL can only enhance B cells and macrophage functions. This is partly due to LBPF4 being able to more significantly enhance lymphocytes NF-κB activity.
We are pursuing potentβ‐site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors in an effort to identify suitable Alzheimer’s disease (AD) drug candidates. Employing a homogeneous, time‐resolved fluorescence technique, we determined the selectivity of compound VIa. We then conducted a cell‐based assay using the huAPPswe/huBACE1 transgenic CHO cell to investigate the effect on the β‐cleavage of APP. The effect of VIa anti‐AD was valued using both acute and subchronic dosing paradigms in PrPhAPPswe/PS1ΔE9 transgenic mice. Our results have shown that the novel compound VIa exhibits potent inhibitory effects with and IC50=5.9 nM and displays 30.8‐fold, 7500‐fold and 17533‐fold selectivity against the other aspartic proteases BACE2, cathepsin D and renin, respectively. In cellular assays, VIa moderately reduces Aβ production: Aβ1‐40 with an IC50 =143 nM and 1 nM VIa reduced Aβ1‐42 by 40.17%. Concomitant with VIa inhibiting the β‐cleavage of amyloid precursor protein (APP), VIa increases the production of sAPPα with an approximate EC50 of 16.5 nM. In testing this compound’s efficacy in vivo, the oral administration of VIa resulted in a significant decrease in Aβ1‐40 and Aβ1‐42 in the blood of a mouse model of AD by 17.5‐72.44% and 14.5‐80.32%, respectively. This result indicates that the novel compound VIa is a small, potent, selective, and nonpeptidic BACE1 inhibitor.Grant Funding Source: the National Science and Technology Major Project (2012ZX09301003‐002‐001, 2013ZX09508104)
In clinical studies, the findings on sulfur mustard (SM) toxicity for CD3+CD4+ and CD3+CD8+ T lymphocyte subsets are contradictory. In animal experiments, the effect of SM on the T cell number and proliferation is incompatible and is even the opposite of the results in human studies. In this study, we observed the dynamic changes of T lymphocytes in the first week in a high-dose SM-induced model.
Recognition of the utility of the traditional Chinese medicine Lycium barbarum L. has been gradually increasing in Europe and the Americas. Many immunoregulation and antitumor effects of L. barbarum polysaccharides (LBP) have been reported, but its molecular mechanism is not yet clear. In this study, we reported that the activity of the polysaccharide LBPF4-OL, which was purified from LBP, is closely associated with the TLR4–MAPK signaling pathway. We found that LBPF4-OL can significantly induce TNF-α and IL-1β production in peritoneal macrophages isolated from wild-type (C3H/HeN) but not TLR4-deficient mice (C3H/HeJ). We also determined that the proliferation of LBPF4-OL-stimulated lymphocytes from C3H/HeJ mice is significantly weaker than that of lymphocytes from C3H/HeN mice. Furthermore, through a bio-layer interferometry assay, we found that LPS but not LBPF4-OL can directly associate with the TLR4/MD2 molecular complex. Flow cytometry analysis indicated that LBPF4-OL markedly upregulates TLR4/MD2 expression in both peritoneal macrophages and Raw264.7 cells. As its mechanism of action, LBPF4-OL increases the phosphorylation of p38-MAPK and inhibits the phosphorylation of JNK and ERK1/2, as was observed through Western blot analysis. These data suggest that the L. barbarum polysaccharide LBPF4-OL is a new Toll-like receptor 4/MD2-MAPK signaling pathway activator and inducer.
It is well known that GnRH analogs can self-assemble into amyloid fibrils and that the duration of action of GnRH analogs depends on the ability of the amyloid to slowly release active peptides. The aim of this study was to investigate the influence of the amino acid residues at position 7 of GnRH analogues on peptide self-assembly. It was found that the dominant shape of the nanostructure can be changed when the structures of the residues at position 7 differ significantly from that of leucine in Degarelix. When the backbone length was extended (peptide 9), or the side chain of the residue at position 7 was replaced by an aromatic ring (peptide 6), or the rotation of the amide bond was restricted (peptide 8), the nanostructure changed from fibrils to vesicles. The results also indicate that the increasing hydrophilicity had little influence on the nanostructure morphology. In addition, a suitable release rate was found to play a more important role for the duration of the peptide action by maintaining the equilibrium between the drug concentration and the persistent release time, while the nanostructure shape was found to exert little influence on the duration of the peptide action.
β-site amyloid-β protein precursor cleaving enzyme 1 (BACE1) is the first protease and the rate limiting enzyme in the genesis of amyloid-β (Aβ). This protein remains an important potential disease-modifying target for the development of drugs to treat Alzheimer's disease (AD). We are pursuing potent BACE1 inhibitors in an effort to identify suitable AD drug candidates. Our results have shown that the novel compound VIa exhibits potent inhibitory effects with IC50 = 5.9 nM and displays 30.8-fold, 7500-fold and 17533-fold selectivity against the other aspartic proteases BACE2, cathepsin D and renin, respectively. In cellular assays, VIa moderately reduces Aβ production: Aβ(1-40) with an IC50 = 143 nM and 1 nM VIa reduced Aβ(1-42) by 40.17%. Concomitant with VIa inhibiting the β-cleavage of amyloid-β protein precursor (AβPP), VIa increases the production of sAβPPα with an approximate EC50 of 16.5 nM. In testing this compound's efficacy in vivo, the oral administration of VIa resulted in a significant decrease in Aβ(1-40) and Aβ(1-42) in the blood of a mouse model of AD by 17.5-72.44% and 14.5-80.32%, respectively. This indicates that the novel compound VIa is a small, potent, selective, and non-peptidic BACE1 inhibitor.
The histamine-releasing potency of gonadotropin-releasing hormone (GnRH) antagonists induced the serious side effect in clinical application. Because the histamine-releasing peptides usually had one or more basic amino acids. Therefore, the carboxyl groups were introduced to the position 6, 8 or N-terminal of GnRH in order to develop the safe GnRH antagonists, and novel GnRH analogues were synthesized. The experimental results showed that some GnRH analogues with carboxyl group not only have low histamine-releasing potency, but also retained intrinsical testesterone-inhibiting bioactivity. It suggested the method of decreasing the histamine-releasing potency of the peptides by introducing the carboxyl groups was feasible.