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1.
Artigo em Inglês | MEDLINE | ID: mdl-31788852

RESUMO

BACKGROUND: To investigate the correlation between the level of circulating vitamin D and the development of colorectal cancer (CRC), and to clarify the effect and mechanism of vitamin D on the development of CRC. METHODS: Serum samples from 63 patients with colorectal cancer (CRC group) and 61 healthy volunteers (Normal group) were collected. AOM+DSS induced CRC mouse model and dietary models with different doses of vitamin D were established to verify whether vitamin D supplementation could reverse the occurrence and development of CRC at the overall animal level. Intestinal barrier integrity and microbial defense response were evaluated by detection of intestinal flora and expression of related genes. RESULTS: In the clinical serum samples, compared with the normal group, the level of 25 (OH) D3 in the CRC group was relatively low (P<0.01), which was consistent with the clinical situation in mice. Vitamin D deficiency aggravated the deterioration of enteritis and intestinal cancer in CRC mice, while the overall condition of CRC mice improved after vitamin D supplementation. Vitamin D has a significant regulatory effect on the homeostasis of the intestinal flora, particularly in the regulation of intestinal probiotics, Akkermansia muciniphila-mediated colon barrier integrity. CONCLUSIONS: Vitamin D deficiency is closely related to the high incidence of CRC, and vitamin D supplementation can inhibit the occurrence and development of CRC. Vitamin D plays a role in the reversal of CRC mainly through the regulation of intestinal flora, especially the regulation of Akkermansia muciniphila-mediated colon barrier integrity.

2.
Int J Nanomedicine ; 14: 7431-7446, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31686815

RESUMO

Background: Low density lipoprotein (LDL) has been regarded as a promising antitumor drug vehicle. However some problems, such as rare source, difficulty of large-scale production, and potential safety concerns, hinder its clinical application. Purpose: The objective of this study is to develop a biomimetic LDL nanocarrier by replacing the native apolipoprotein B-100 (apoB-100) with an artificial amphipathic peptide and demonstrate its antitumor efficacy. Methods: The amphipathic hybrid peptide (termed as FPL) consisting of a lipid binding motif of apoB-100 (LBMapoB)-polyethylene glycol (PEG)-folic acid (FA) was synthesized and characterized by 1H NMR and circular dichroism. FPL decorated lipoprotein-mimic nanoparticles (termed as FPLM NPs) were prepared by a modified solvent emulsification method. Paclitaxel (PTX) was incorporated into NPs and its content was quantified by HPLC analysis. The morphology of NPs was observed by transmission electron microscopy (TEM), and the particle size and zeta potential of NPs were determined by dynamic light scattering (DLS). The colloidal stability of FPLM NPs was evaluated in PBS containing bovine serum albumin (BSA). In vitro release of PTX loaded FPLM NPs was evaluated using the dialysis method. Cellular uptake and cytotoxity assayswere evaluated on human cervical cancer cells (HeLa) and lung cancer cells (A549). Tumor inhibition in vivo was investigated in M109 tumor-bearing mice via tail vein injection of Taxol formulation and PTX loaded NPs. Results: The composition of FPLM NPs, including cholesteryl oleate, glyceryl trioleate, cholesterol, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and FPL peptides, was optimized to be 5:1:1:3:10 (w/w). FPLM NPs had a spherical shape with a mean diameter of 83 nm and a negative charge (-12 mV). FPLM NPs with optimum formulation had good colloidal stability in BSA solution.The release of PTX from FPLM NPs was slow and sustained. The uptake of FPLM NPs was higher in folate receptor (FR) overexpressing tumor cells (HeLa cells) than in FR deficient tumor cells (A549 cells). The intracellular distribution indicated that FPLM NPs had the lysosome escape capacity. The internalization mechanism of FPLM NPs was involved with clathrin- and caveolae-mediated endocytosis and FR played a positive role in the internalization of FPLM NPs. The CCK-8 assay demonstrated that FPLM NPs exhibited notably better anti-tumor effect than Taxol formulation in vitro. Moreover, PTX loaded FPLM NPs produced very marked anti-tumor efficiency in M109 tumor-bearing mice in vivo. Conclusion: FPLM NPs is a promising nanocarrier which can improve the therapeutic effect and reduce the side effects of antitumor drugs.

3.
Cell Biol Toxicol ; 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31768838

RESUMO

Inflammation reaction mediated by NLRP3 inflammasome and Nrf2-related oxidative stress are vital participants in the development of diabetic nephropathy (DN) and closely associated to kidney fibrosis. Nrf2, a known antioxidative transcription factor, has been reported to activate NLRP3 inflammasome through its downstream factors (HO-1, NQO1, etc.) recently. AB38b is a newly synthesized biphenyl diester derivative with a Nrf2 activation property. This research aims to evaluate the renal protective effects of AB-38b and to elucidate the anti-inflammation mechanisms involved. Type 2 diabetic mice induced by high fat diet with streptozocin (STZ) and high glucose-cultured mouse glomerular mesangial cells (GMCs) were used in current study. Results showed that administration of AB-38b improved the kidney function while attenuated renal fibrosis progression in diabetic mice together with reducing the extracellular matrix (ECM) accumulation of GMCs cultured in high glucose. Mechanistically, treatment with AB-38b significantly decreased the high level of NLRP3 inflammasome in diabetic condition by inhibiting the ROS/TXNIP/NLRP3 signaling pathway. And meanwhile, AB-38b treatment effectively improved Nrf2 signaling during diabetic condition. Furthermore, knocking down the gene expression of Nrf2 by siRNA in GMCs abolished the inhibition effect of AB-38b on NLRP3 inflammasome activation and ECM accumulation. Taken together, our data suggest that AB-38b was able to improve the renal function of diabetic mice, and the NLRP3 inflammasome inhibition effect of AB-38b was responsible for the renal protective effect. Further exploration indicate that Nrf2 plays pivotal role in AB-38b's attenuation of DN progression through inhibiting NLRP3 inflammasome activation.

4.
ACS Sens ; 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31701738

RESUMO

Selenocysteine (Sec), a vital member of reactive selenium species, is closely implicated in diverse pathophysiological states, including cancer, cardiovascular diseases, diabetes, neurodegenerative diseases, and male infertility. Monitoring Sec in vivo is of significant interest for understanding the physiological roles of Sec and the mechanisms of human diseases associated with abnormal levels of Sec. However, no bioluminescence probe for real-time monitoring of Sec in vivo has been reported. Herein, we present a novel bioluminescent probe BF-1 as an effective tool for the determination of Sec in living cells and in vivo for the first time. BF-1 has advantages of high sensitivity (a detection limit of 8 nM), remarkable bioluminescence enhancement (580-fold), reasonable selectivity, low cytotoxicity, and high signal-to-noise ratio imaging feasibility of Sec in living cells and mice. More importantly, BF-1 affords high sensitivity for monitoring Sec stimulated by Na2SeO3 in tumor-bearing mice. These results demonstrate that our new probe could serve as a powerful tool to selectively monitor Sec in vivo, thus providing a valuable approach for exploring the physiological and pathological functions and anticancer mechanisms of selenium.

5.
Acta Pharmacol Sin ; 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645661

RESUMO

Extracellular matrix (ECM) deposition following reactive oxygen species (ROS) overproduction has a key role in diabetic nephropathy (DN), thus, antioxidant therapy is considered as a promising strategy for treating DN. Here, we investigated the therapeutic effects of AB38b, a novel synthetic α, ß-unsaturated ketone compound, on the oxidative stress (OS) and ECM accumulation in type 2 diabetes mice, and tried to clarify the mechanisms underlying the effects in high glucose (HG, 30 mM)-treated mouse glomerular mesangial cells (GMCs). Type 2 diabetes model was established in mice with high-fat diet feeding combined with streptozocin intraperitoneal administration. The diabetic mice were then treated with AB38b (10, 20, 40 mg· kg-1· d-1, ig) or a positive control drug resveratrol (40 mg· kg-1· d-1, ig) for 8 weeks. We showed that administration of AB38b or resveratrol prevented the increases in malondialdehyde level, lactate dehydrogenase release, and laminin and type IV collagen deposition in the diabetic kidney. Simultaneously, AB38b or resveratrol markedly lowered the level of Keap1, accompanied by evident activation of Nrf2 signaling in the diabetic kidney. The underlying mechanisms of antioxidant effect of AB38b were explored in HG-treated mouse GMCs. AB38b (2.5-10 µM) or resveratrol (10 µM) significantly alleviated OS and ECM accumulation in HG-treated GMCs. Furthermore, AB38b or resveratrol treatment effectively activated Nrf2 signaling by inhibiting Keap1 expression without affecting the interaction between Keap1 and Nrf2. Besides, AB38b treatment effectively suppressed the ubiquitination of Nrf2. Taken together, this study demonstrates that AB38b ameliorates experimental DN through antioxidation and modulation of Keap1/Nrf2 signaling pathway.

6.
Biosens Bioelectron ; 144: 111665, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494508

RESUMO

The superoxide anion (O2•-) is an important reactive oxygen species (ROS) in the brain system, which has been associated with the development of many neurological diseases, including Alzheimer's disease (AD). Herein, we introduced a carbon fiber microelectrode (CFME) based in vivo technique for specific and sensitive monitoring of the O2•- radical in the living brains of both normal and AD model rats. Compared with other reported superoxide dismutase (SOD) electrochemical biosensors, the microsensor presented in our work was featured in the coating of a functionalized ionic liquid polymer (PIL) onto PB nanoparticles (PBNPs) and carbon nanotubes (CNT). It was demonstrated that the cationic and carboxyl-rich PILs provided abundant interaction sites with SOD to prevent enzyme leakage from sensor, which was beneficial for the enhancement of sensitivity. Additionally, CCK-8 assay and autoxidation of pyrogallol tests showed that MCF-7 cells maintained a high viability after incubated with PIL and most of the SOD bioactivity was retained in the presence of PIL, which implied the PIL itself possessed an excellent biocompatibility. These properties allow the sensor to track the fluctuation of O2•- levels in vivo between normal and AD rats. This is the first report on application of functionalized PIL to reveal the O2•- related pathological process of AD.

7.
Arch Toxicol ; 93(10): 2863-2878, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31444509

RESUMO

Acetaminophen (APAP)-induced liver injury is the main cause of acute liver failure. This study investigated the role of microsomal prostaglandin E synthase 2 (mPGES-2), discovered as one of the prostaglandin E2 (PGE2) synthases, in mediating APAP-induced liver injury. Using mPGES-2 wild-type (WT) and knockout (KO) mice, marked resistance to APAP-induced liver damage was found in mPGES-2 KO, as indicated by robust improvement of liver histology, changes in liver enzyme release, and marked decrease in APAP-cysteine adducts (APAP-CYS) and inflammatory markers. Moreover, the results confirmed that increase in liver PGE2 content in KO mice under basal conditions was not critical for the protection from APAP-induced liver injury. Importantly, mPGES-2 deletion inhibited the production of malondialdehyde (MDA), increasing glutathione (GSH) level. Enhanced GSH level may contribute to the inhibition of APAP toxicity in mPGES-2 KO mice. To further elucidate the role of mPGES-2 in the liver injury induced by APAP, adeno-associated viruses (AAV) were used to overexpress mPGES-2 in the liver. The results showed that mPGES-2 overexpression aggravates liver injury associated with an increase in inflammatory markers and chemokines after APAP treatment. Moreover, a lower level of GSH was detected in the mPGES-2 overexpression group compared to the control group. Collectively, our findings indicate that mPGES-2 plays a critical role in regulating APAP-induced liver injury, possibly by regulating GSH and APAP-CYS level, which may provide a potential therapeutic strategy for the prevention and treatment of APAP-induced liver injury.

8.
Phytother Res ; 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31452288

RESUMO

Multiphase pathological processes involve in Type 2 diabetes (T2DM)-induced nonalcoholic fatty liver disease (NAFLD). However, the therapies are quite limited. In the present study, the hepatoprotective effects and underlying mechanisms of quercetin in T2DM-induced NAFLD were investigated. T2DM-induced NAFLD and quercetin treatment models were established in vivo and in vitro. The results revealed that quercetin alleviated serum transaminase levels and markedly reduced T2DM-induced histological alterations of livers. Additionally, quercetin restored superoxide dismutase, catalase, and glutathione content in livers. Not only that, quercetin markedly attenuated T2DM-induced production of interleukin 1 beta, interleukin 6, and TNF-α. Accompanied by the restoration of the increased serum total bile acid (p = .0001) and the decreased liver total bile acid (p = .0005), quercetin could reduce lipid accumulation in the liver of db/db mice. Further mechanism studies showed that farnesoid X receptor 1/Takeda G-protein-coupled receptor 5 signaling pathways was involved in quercetin regulation of lipid metabolism in T2DM-induced NAFLD. In high D-glucose and free fatty acid cocultured HepG2 cells model, quercetin eliminated lipid droplets and restored the upregulated total cholesterol and triglyceride levels. Similar to the findings in mice, quercetin could also activate farnesoid X receptor 1/Takeda G-protein-coupled receptor 5 signaling pathway. These findings suggested that quercetin might be a potentially effective drug for the treatment of T2DM-induced NAFLD.

9.
Biomed Pharmacother ; 117: 109097, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31212128

RESUMO

An overdose of the most popular analgesic, acetaminophen (APAP), is one of the leading causes of acute liver failure. It is well established that glutathione is exhausted by APAP-reactive intermediate N­acetyl­p­benzoquinone-imine (NAPQI). This leads to elevated phosphorylated-c-Jun N-terminal kinase (p-JNK), which further activates reactive oxygen species (ROS), initiates an inflammatory response, and finally leads to severe hepatic injury. The present study was conducted to investigate the protective role of mangiferin (MAN), a naturally occurring xanthone and anti-oxidant, on APAP-induced hepatotoxicity. C57BL/6 mice were pretreated with or without MAN at 1 h prior to APAP challenge. MAN was administered at a dose of 12.5-50 mg/kg along with APAP at a dose of 400 mg/kg. According to the ALT/AST ratio, 25 mg/kg MAN was the most potent dose for further experiments. Serum ALT and AST depletion were observed in APAP + MAN (25 mg/kg)-treated mice at 6, 12, and 24 h. Early (1 h after APAP treatment) GSH depletion by APAP overdose was restored by MAN treatment, which reduced APAP-Cys adduct formation and promoted protection. p-JNK downregulation and AMPK activation were observed in MAN-treated mice, which could mechanistically reduce oxidative stress and inflammation. MAN up-regulated liver GSH and SOD and reduced lipid peroxidation. HO-1 protein and p47 phox mRNA expression indicated that MAN regulated oxidative stress along with JNK deactivation. The expression of inflammatory response genes TNF-α, IL-6, MCP-1, CXCL-1, and CXCL-2 reached the basal levels after MAN treatment. mRNA, protein, and serum levels of IL-1ß were reduced, and NF-κB expression was similar to that of the MAN-treated APAP mice. MAN post-treatment (1 h after APAP treatment) also protected the mice from hepatotoxicity. In conclusion, MAN had a protective and therapeutic role in APAP-induced hepatotoxicity by improving the metabolism of acetaminophen and APAP-Cys adduct formation followed by JNK-mediated oxidative stress and inflammation.

10.
Acta Pharmacol Sin ; 40(12): 1555-1567, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31235817

RESUMO

Epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells is one of the potential mechanisms of renal fibrosis, which promotes the development of diabetic nephropathy (DN). However, the molecular mechanisms of EMT remain largely unknown. Tuberous sclerosis proteins TSC1 and TSC2 are key integrators of growth factor signaling, and the loss of TSC1 or TSC2 function leads to a spectrum of diseases that underlie abnormalities in cell growth, proliferation, differentiation, and migration. In this study, we investigated the effects of TSC1 on high glucose (HG)-induced EMT of human proximal tubular epithelial HK-2 cells in vitro and renal fibrosis in TSC1-/- and db/db mice. We found that the exposure of HK-2 cells to HG (30 mM) time-dependently decreased TSC1 expression, increased the phosphorylation of mTORC1, P70S6K, and 4E-BP-1, and promoted cell migration, resulting in EMT. Transfection of the cells with TSC1 mimic significantly ameliorated HG-induced EMT of HK-2 cells. The tubules-specific TSC1 knockout mice (TSC1-/-) displayed a significant decline in renal function. TSC1-/- mice, similar to db/db mice, showed greatly activated mTORC1 signaling and EMT process in the renal cortex and exacerbated renal fibrosis. Overexpression of TSC1 through LV-TSC1 transfection significantly alleviated the progression of EMT and renal fibrosis in the renal cortex of db/db mice. Taken together, our results suggest that TSC1 plays a key role in mediating HG-induced EMT, and inhibition of TSC1-regulated mTORC1 signaling may be a potential approach to prevent renal fibrosis in DN.

11.
Intern Med ; 58(16): 2341-2347, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31118371

RESUMO

Objective Previous studies have suggested that variations in the ABCC8 gene may be closely associated with T2DM susceptibility and repaglinide response. However, these results have not been entirely consistent, and there are no related studies in a Chinese population, suggesting the need for further exploration. The current study investigated the associations of the ABCC8 rs1801261 polymorphism with type 2 diabetes mellitus (T2DM) susceptibility and repaglinide therapeutic efficacy in Chinese Han T2DM patients. Methods A total of 234 T2DM patients and 105 healthy subjects were genotyped for ABCC8 rs1801261 polymorphism by a polymerase chain reaction-restriction fragment length polymorphism assay. A total of 70 patients with the same genotypes of CYP2C8*3 139Arg and OATP1B1 521TT were randomized to orally take 3 mg repaglinide per day (1 mg each time before meals) for 8 consecutive weeks. The pharmacodynamic parameters of repaglinide and biochemical indicators were then determined before and after repaglinide treatment. Results The frequency of ABCC8 rs1801261 allele was higher in T2DM patients than in the control subjects (22.6% vs.11.0%, p<0.01). After repaglinide treatment, T2DM patients carrying genotype CT showed a significantly attenuated efficacy on FPG (p<0.01) and HbA1c (p<0.01) compared with those with genotype CC. Conclusion These results suggested that the ABCC8 rs1801261 polymorphism might influence T2DM susceptibility and the therapeutic effect of repaglinide in Chinese Han T2DM patients. This study was registered in the Chinese Clinical Trial Register on May 14, 2013 (No. ChiCTR-CCC13003536).

12.
Metabolism ; 96: 33-45, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31028762

RESUMO

BACKGROUND: Renal fibrosis promotes the development of diabetic nephropathy (DN). A growing number of studies have reported that Yin Yang 1 (YY1), which is involved in cellular proliferation and differentiation, plays a crucial role in the pathogenesis of many diseases, such as pulmonary fibrosis, hepatic steatosis and cancer. METHODS: We detected the expression of YY1 under various glucose concentration and time gradient conditions. Rapamycin was used to verify the mTORC1/p70S6K/YY1 signaling pathway in HK-2 cells. We used db/db mice to examine the connection between renal fibrosis and YY1. A luciferase assay and chromatin immunoprecipitation (ChIP) assay were used to identify whether YY1 directly regulated α-SMA by binding to the α-SMA promoter. RNA silencing and overexpression were performed by using a YY1 expression/knockdown plasmid to investigate the function of YY1 in renal fibrosis of DN. RESULTS: YY1 expression and subsequent nuclear translocation were upregulated in a glucose- and time-dependent manner via the mTORC1/p70S6K signaling pathway in HK-2 cells. YY1 expression and nuclear translocation was significantly upregulated in db/db mice. Furthermore, YY1 upregulated α-SMA expression and activity in high-glucose-cultured HK-2 cells. Overexpression of YY1 promoted renal fibrosis in db/m mice mainly by upregulating α-SMA expression and inducing epithelial-mesenchymal transition (EMT) in vitro and in vivo. Finally, downregulation of YY1 reversed renal fibrosis by improving EMT in vivo and in vitro. CONCLUSIONS: These results reveal that upregulation of YY1 plays a critical role in HG-induced deregulation of EMT-associated protein expression, which finally results in renal fibrosis of DN. Therefore, decreasing YY1 expression might represent a new therapeutic target for diabetic nephropathy-induced renal fibrosis.

13.
Neuropharmacology ; 153: 20-31, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31026437

RESUMO

Resveratrol is a natural non-flavonoid polyphenol found in red wine, which has numerous pharmacological properties including anti-stress and antidepressant-like abilities. However, whether the antidepressant- and anxiolytic-like effects of resveratrol are related to the inhibition of phosphodiesterase 4 (PDE4) and its subtypes remains unknown. The same holds true for the subsequent cAMP-dependent pathway. The first set of studies investigated whether resveratrol exhibited neuroprotective effects against corticosterone-induced cell lesion as well as its underlying mechanism. We found that 100 µM corticosterone induced PDE2A, PDE3B, PDE4A, PDE4D, PDE10 and PDE11 expression in HT-22 cells, which results in significant cell lesion. However, treatment with resveratrol increased cell viability in a dose- and time-dependent manner. These effects seem related to the inhibition of PDE4D, as evidenced by resveratrol dose-dependently decreasing PDE4D expression. In addition, the PKA inhibitor H89 reversed resveratrol's effects on cell viability. Resveratrol prevented corticosterone-induced reduction in cAMP, pVASP(s157), pCREB, and BDNF levels, indicating that cAMP signaling is involved in resveratrol-induced neuroprotective effects. Not to mention, PDE4D knockdown by PDE4D siRNA potentiated the effect of low dose of resveratrol on cAMP, pVASP, pCREB, and BDNF expression, while PDE4D overexpression reversed the effect of high dose of resveratrol on the expression of the above proteins. Finally, the subsequent in vivo data supports the in vitro findings, suggesting that resveratrol-induced antidepressant- and anxiolytic-like effects are mediated by PDE4D. Overall, these findings support the hypothesis that PDE4D-mediated cAMP signaling plays an important role in resveratrol's protective effects on stress-induced depression- and anxiety-like behavior.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31022424

RESUMO

The dysfunction of mitochondria plays important roles in the development of depression. Interestingly, increasing numbers of evidence show the therapeutic benefits of mitochondria transfer. Therefore, we hypothesized that injection of exogenous mitochondria would contribute to ameliorate depressive-like symptoms. In this study, the antidepressant-like effect of intravenous isolated mitochondria was evaluated on a lipopolysaccharide (LPS)- induced model of depression. The depressive-like behaviors were assessed using forced swim test (FST), tail suspension test (TST) and sucrose preference test. Besides, the neurogenesis, expression of brain-derived neurotrophic factor (BDNF), glial activation, neuroinflammation, oxidative stress and ATP production were determined in the hippocampus. The results showed that treatment of isolated mitochondria decreased the immobility time of mice in the FST and TST, and attenuated the decrease in sucrose preference test. Moreover, isolated mitochondria significantly reduced the activation of astrocyte and microglia as well as neuroinflammation (i.e. 1 L-1ß, TNF-α and COX-2), increased BDNF expression and neurogenesis, restored the dysfunction of ATP production and oxidative stress in inflammation- induced depression. Taken together, the data suggested for the first time that injection of isolated mitochondria ameliorated LPS- induced depressive-like behaviors. The new discovery for the present study provides that mitochondrial transplantation might act as a new therapeutic strategy for MDD.

15.
Biochem Pharmacol ; 164: 45-52, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30905656

RESUMO

Elevated circulating free fatty acid (FFA) level is closely linked to the pathogenesis of insulin resistance and type 2 diabetes mellitus. Activation of the adenosine A1 receptor (A1R) inhibits lipolysis in adipocytes and hence reduces the concentration of FFA, which represents a potential target for the development of antilipolytic agents. We aimed to assess the binding affinity as well as target binding kinetics of A1R agonists and further delineate a possible relationship with their antilipolytic effect in adipocytes. Radioligand binding assays were performed to determine the affinity and kinetics of three representative A1R agonists, namely CPA, LUF6944 and LUF6941, on the rat A1R. Functional responses to these agonists were examined in both a recombinant cell system and physiologically relevant rat adipocytes. The three A1R agonists displayed similar affinity while divergent target binding kinetics on the rat A1R. Irrespective of equilibrium binding affinity, temporal analysis of receptor signaling demonstrated persistent functional responses for the long residence time agonist, despite removal of excess agonist, in both a recombinant cell system and in rat adipocytes. By contrast, such effect was less pronounced or even lost for agonists with medium or short receptor residence time, respectively. Our results indicate that ligand receptor binding kinetics rather than their affinity or potency play an essential role in regulating cellular responses. The long residence time A1R agonist produces a sustained wash-resistant antilipolytic effect in rat adipocytes and thus may represent a potential antilipolytic alternative for further investigation.

16.
Comput Biol Chem ; 78: 290-296, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30605854

RESUMO

Human epidermal growth factor receptor 2 (ErbB2) is an attractive therapeutic target for metastatic breast cancer. The kinase has been clinically observed to harbor a gatekeeper mutation T798M in its active site, which causes acquired resistance to the first-line targeted breast cancer therapy with small-molecule tyrosine kinase inhibitors. Previously, several theories have been proposed to explain the molecular mechanism of gatekeeper mutation-caused drug resistance, such as blocking of inhibitor binding and increasing of ATP affinity. In the current study, the direct binding of three wild type-selective inhibitors (Lapatinib, AEE788 and TAK-285) and two wild type-sparing inhibitors (Staurosporine and Bosutinib) to the wild-type ErbB2 and its T798M mutant are investigated in detail by using rigorous computational analysis and binding affinity assay. Substitution of the polar threonine with a bulky methionine at residue 798 can impair and improve the direct binding affinity of wild type-selective and wild type-sparing inhibitors, respectively. Hindrance effect is responsible for the affinity decrease of wild type-selective inhibitors, while additional nonbonded interactions contribute to the affinity increase of wild type-sparing inhibitors, thus conferring selectivity to the inhibitors for mutant over wild type. The binding affinity of Staurosporine and Bosutinib to ErbB2 kinase domain is improved by 11.9-fold and 2.1-fold upon T798M mutation, respectively. Structural analysis reveals that a nonbonded network of S-π contact interactions (for Staurosporine) or an S-involving halogen bond (for Bosutinib) forms with the sulfide group of mutant Met798 residue.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Receptor ErbB-2/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Estrutura Molecular , Mutação , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Relação Estrutura-Atividade
17.
Pain ; 160(5): 1082-1092, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30649099

RESUMO

Accumulating evidence has demonstrated that the enhanced synaptic plasticity of nociceptive interneurons in the spinal dorsal horn is the basis of central sensitization in neuropathic pain. Our previous results demonstrated that sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase, alleviates neuropathic pain in type 2 diabetes mellitus rats. SIRT1 has also been reported to regulate synaptic plasticity in different brain neurons. However, the role of SIRT1 in synaptic plasticity of spinal dorsal horn neurons remains unknown. In this study, we found that in the spinal dorsal horn of diabetic neuropathic pain (DNP) rats and db/db mice, decreased SIRT1 expression was accompanied by enhanced structural synaptic plasticity. The levels of postsynaptic density protein 95 (PSD-95), growth-associated protein 43 (GAP43), and synaptophysin increased in the spinal dorsal horn of DNP rats and db/db mice and in high glucose-cultured primary spinal neurons. Upregulation of spinal SIRT1 by SIRT1 activator SRT1720 relieved pain behavior, inhibited the enhanced structural synaptic plasticity in rats and db/db mice with DNP, and decreased the levels of synapse-associated proteins in DNP rats, db/db mice, and high glucose-cultured spinal neurons. SIRT1-shRNA induced pain behavior and enhanced structural synaptic plasticity in normal rats and increased synapse-associated proteins levels in normal rats and spinal neurons. Intrathecal injection of AAV-Cre-EGFP into SIRT1 mice also induced pain behavior and enhanced synaptic plasticity of the spinal dorsal horn neurons. These results suggest that SIRT1 plays an important role in the progression of DNP by regulating synaptic plasticity of spinal dorsal horn neurons.


Assuntos
Neuropatias Diabéticas/patologia , Plasticidade Neuronal/fisiologia , Células do Corno Posterior/fisiologia , Sirtuína 1/metabolismo , Medula Espinal/patologia , Animais , Células Cultivadas , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patologia , Neuropatias Diabéticas/tratamento farmacológico , Neuropatias Diabéticas/genética , Modelos Animais de Doenças , Embrião de Mamíferos , Glucose/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Masculino , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/genética , Células do Corno Posterior/efeitos dos fármacos , Células do Corno Posterior/ultraestrutura , RNA Interferente Pequeno/uso terapêutico , Ratos , Ratos Sprague-Dawley , Sirtuína 1/genética , Regulação para Cima/fisiologia
18.
ACS Sens ; 4(2): 471-478, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30693761

RESUMO

Herein, we provide a proof of concept for a novel strategy that targets the assessment of the aggregation of amyloid-ß (Aß) by simultaneously determining its oligomers (Aßo) and fibrils (Aßf) in one analytical system. By fabricating and combining two immunosensors for Aßo and Aßf, respectively, we constructed a two-channel electrochemical system. The ratio of Aßf to Aßo was calculated and taken as a possible criterion for evaluating the extent of aggregation. Thereby, the presence of and transformation between oligomers and fibrils were accurately probed by incubating the Aß monomer for different times and then calculating the ratios of Aßf to Aßo. The applicability of this method was further validated by tracking the dynamic progress of Aß aggregation in the cerebrospinal fluid and tissues of Alzheimer's disease (AD) rats, which revealed that the ratio of Aßf to Aßo in rat brain gradually increased with the progression of AD, which was indicative of the severity of peptide aggregation during this process. Overall, this study represents the first example of a quantitative strategy for precisely evaluating the aggregation process that is related to pathological events in AD brain.

19.
J Affect Disord ; 242: 52-59, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30172225

RESUMO

BACKGROUND: Numerous studies indicate that inflammation plays important roles in the development of depression. Astrocytes are crucial regulators of immune response in the central nervous system, and strongly activated by pro-inflammatory cytokines. We hypothesized that inhibition of activated astrocytes contributed to ameliorate depressive-like symptoms. METHODS: This study evaluated the antidepressant-like effect of inhibition of activated astrocytes, by a well-established astrocyte inactivator fluorocitrate (FC), on a lipopolysaccharide (LPS)-induced model of depression. Forced swim test (FST), tail suspension test (TST) and sucrose preference test were used to assess depressive-like behaviors. The expression of fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF) and neuroinflammation were determined in the hippocampus and cortex. RESULTS: The results demonstrated that LPS increased immobility time in the TST and FST, reduced sucrose preference as well. LPS also enhanced the expression of IL-1ß, TNF-α, iNOS and GFAP, accompanying with decreased expression of BDNF in the hippocampus and cortex. Inhibition of activated astrocytes by FC significantly prevented LPS- induced alteration in the FST, TST and sucrose preference test. Moreover, in the hippocampus and cortex, inhibition of activated astrocytes by FC significantly attenuated increases of neuroinflammation and GFAP whereas reversed decrease of BDNF in LPS- challenged depression. CONCLUSIONS: Taken together, the results suggest that inhibition of activated astrocytes ameliorates LPS-induced depressive-like behavior, providing the first evidence that inhibition of activated astrocytes might represent a novel therapeutic target for depression.


Assuntos
Astrócitos/efeitos dos fármacos , Citratos/farmacologia , Transtorno Depressivo/prevenção & controle , Lipopolissacarídeos/toxicidade , Animais , Antidepressivos/uso terapêutico , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Córtex Cerebral/metabolismo , Citocinas/metabolismo , Transtorno Depressivo/induzido quimicamente , Transtorno Depressivo/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/metabolismo , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Reação em Cadeia da Polimerase em Tempo Real , Natação , Fator de Necrose Tumoral alfa/metabolismo
20.
Eur J Med Chem ; 162: 59-69, 2018 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-30408749

RESUMO

Oxidative stress plays a significant role in the pathogenesis of various human diseases. In this study, a series of bifendate derivatives bearing acrylamide moiety were synthesized and evaluated as anti-oxidant agents. Biological evaluation indicated that compounds 6a and 6e displayed more potent cytoprotective effect against H2O2-induced HBZY-1 mesangial cells death than lead compound bifendate and positive control resveratrol and sulforaphane. Preliminary anti-oxidant mechanism studies showed that compound 6e could diminish the ROS accumulation by dose- and time-dependently activating Nrf2 and increasing the expression of downstream detoxification enzymes NQO-1, HO-1, GCLM and GCLC at protein and mRNA levels, thus displaying potent anti-oxidant activity. Interestingly, the Nrf2 activating effect of 6e is achieved, at least partly, in Michael acceptor and Keap1-dependent manners. These results, together with the low intrinsic cytotoxicity, suggested that compound 6e might be a promising lead for the development of novel anti-oxidant agents to prevent diseases induced by oxidative stress.

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