Bai R

References (7)

Title : 4-Methylbenzylidene camphor triggers estrogenic effects via the brain-liver-gonad axis in zebrafish larvae - Xian_2023_Environ.Pollut__122260
Author(s) : Xian H , Li Z , Ye R , Dai M , Feng Y , Bai R , Guo J , Yan X , Yang X , Chen D , Huang Z
Ref : Environ Pollut , :122260 , 2023
Abstract : 4-Methylbenzylidene camphor (4-MBC), an emerging contaminant, is a widely-used ultraviolet (UV) filter incorporated into cosmetics because it protects the skin from UV rays and counters photo-oxidation. Despite the well-established estrogenic activity of 4-MBC, the link between this activity and its effects on neurobehavior and the liver remains unknown. Thus, we exposed zebrafish larvae to environmentally relevant concentrations of 4-MBC with 1.39, 4.17, 12.5 and 15.4 microg/mL from 3 to 5 days postfertilization. We found that 4-MBC produced an estrogenic effect by intensifying fluorescence in the transgenic zebrafish, which was counteracted by co-exposure with estrogen receptor antagonist. 4-MBC-upregulated estrogen receptor alpha (eralpha) mRNA, and an interaction between 4-MBC and ERalpha suggested ERalpha's involvement in the 4-MBC-induced estrogenic activity. RNA sequencing unearthed 4-MBC-triggered responses in estrogen stimulus and lipid metabolism. Additionally, 4-MBC-induced hypoactivity and behavioral phenotypes were dependent on the estrogen receptor (ER) pathway. This may have been associated with the disruption of acetylcholinesterase and acetylcholine activities. As a result, 4-MBC increased vitellogenin expression and caused lipid accumulation in the liver of zebrafish larvae. Collectively, this is the first study to report 4-MBC-caused estrogenic effects through the brain-liver-gonad axis. It provides novel insight into how 4-MBC perturbs the brain and liver development.
ESTHER : Xian_2023_Environ.Pollut__122260
PubMedSearch : Xian_2023_Environ.Pollut__122260
PubMedID: 37506809

Title : Sertoli cell survival and barrier function are regulated by miR-181c\/d-Pafah1b1 axis during mammalian spermatogenesis - Feng_2022_Cell.Mol.Life.Sci_79_498
Author(s) : Feng Y , Chen D , Wang T , Zhou J , Xu W , Xiong H , Bai R , Wu S , Li J , Li F
Ref : Cell Mol Life Sciences , 79 :498 , 2022
Abstract : Sertoli cells contribute to the formation of the blood-testis barrier (BTB), which is necessary for normal spermatogenesis. Recently, microRNAs (miRNAs) have emerged as posttranscriptional regulatory elements in BTB function during spermatogenesis. Our previous study has shown that miR-181c or miR-181d (miR-181c/d) is highly expressed in testes from boars at 60 days old compared with at 180 days old. Herein, we found that overexpression of miR-181c/d via miR-181c/d mimics in murine Sertoli cells (SCs) or through injecting miR-181c/d-overexpressing lentivirus in murine testes perturbs BTB function by altering BTB-associated protein distribution at the Sertoli cell-cell interface and F-actin organization, but this in vivo perturbation disappears approximately 6 weeks after the final treatment. We also found that miR-181c/d represses Sertoli cell proliferation and promotes its apoptosis. Moreover, miR-181c/d regulates Sertoli cell survival and barrier function by targeting platelet-activating factor acetylhydrolase 1b regulatory subunit 1 (Pafah1b1) gene. Furthermore, miR-181c/d suppresses PAFAH1B1 expression, reduces the complex of PAFAH1B1 with IQ motif-containing GTPase activating protein 1, and inhibits CDC42/PAK1/LIMK1/Cofilin pathway which is required for F-actin stabilization. In total, our results reveal the regulatory axis of miR-181c/d-Pafah1b1 in cell survival and barrier function of Sertoli cells and provide additional insights into miRNA functions in mammalian spermatogenesis.
ESTHER : Feng_2022_Cell.Mol.Life.Sci_79_498
PubMedSearch : Feng_2022_Cell.Mol.Life.Sci_79_498
PubMedID: 36008729

Title : Effect of propeptide mutations on the directed evolution of Rhizomucor miehei lipase - Wang_2022_Protein.Pept.Lett__
Author(s) : Wang J , Bai R , Wu N , Zhang Y , Hu L
Ref : Protein Pept Lett , : , 2022
Abstract : BACKGROUND: A series of mutants of Rhizomucor miehei lipase (RML) screened through four rounds of directed evolution was studied as the research object. The hydrolysis activity of mutants to triglycerides was determined, and their genes were sequenced. Results showed that mutations in the propeptide can improve the activity of RML during the evolution. Two parts of propeptide (wild-type and mutant) and mature region were connected by molecular simulation technology. METHODS: The spatial structure of the most positive mutants containing the mutations in the propeptide was mainly characterized by the increase in the opening angle of the lid structure in the mature region of RML, the enhancement of the hydrophobicity of the active center, and the triad of the active center shifted outward. RESULTS: The three indexes above explain the mechanism of propeptide mutations on the activity change of the target protein. In addition, statistical analysis of all the mutants screened in directed evolution showed that: (1) most of the mutants with increased activity contained mutations of the propeptide; (2) In the later stage of directed evolution, the number of active mutants decreased gradually, and the mutations of inactivated protein mainly occurred in the mature region; and (3) In the last round of directed evolution, the mutations distributed in the propeptide improved the mutant activity further. The results show the propeptide down the evolutionary pressure of RML and delayed emergence of the evolutionary platform. CONCLUSION: These findings reveal the role of propeptide in the evolution of RML and provide strategies for the molecular transformation of other lipases.
ESTHER : Wang_2022_Protein.Pept.Lett__
PubMedSearch : Wang_2022_Protein.Pept.Lett__
PubMedID: 35289250
Gene_locus related to this paper: rhimi-lipas

Title : Discovery of Novel Tacrine-Pyrimidone Hybrids as Potent Dual AChE\/GSK-3 Inhibitors for the Treatment of Alzheimer's Disease - Yao_2021_J.Med.Chem__
Author(s) : Yao H , Uras G , Zhang P , Xu S , Yin Y , Liu J , Qin S , Li X , Allen S , Bai R , Gong Q , Zhang H , Zhu Z , Xu J
Ref : Journal of Medicinal Chemistry , : , 2021
Abstract : Based on a multitarget strategy, a series of novel tacrine-pyrimidone hybrids were identified for the potential treatment of Alzheimer's disease (AD). Biological evaluation results demonstrated that these hybrids exhibited significant inhibitory activities toward acetylcholinesterase (AChE) and glycogen synthase kinase 3 (GSK-3). The optimal compound 27g possessed excellent dual AChE/GSK-3 inhibition both in terms of potency and equilibrium (AChE: IC(50) = 51.1 nM; GSK-3beta: IC(50) = 89.3 nM) and displayed significant amelioration on cognitive deficits in scopolamine-induced amnesia mice and efficient reduction against phosphorylation of tau protein on Ser-199 and Ser-396 sites in glyceraldehyde (GA)-stimulated differentiated SH-SY5Y cells. Furthermore, compound 27g exhibited eligible pharmacokinetic properties, good kinase selectivity, and moderate neuroprotection against GA-induced reduction in cell viability and neurite damage in SH-SY5Y-derived neurons. The multifunctional profiles of compound 27g suggest that it deserves further investigation as a promising lead for the prospective treatment of AD.
ESTHER : Yao_2021_J.Med.Chem__
PubMedSearch : Yao_2021_J.Med.Chem__
PubMedID: 34024109

Title : Investigation of the inhibitory effect of protostanes on human carboxylesterase 2 and their interaction: Inhibition kinetics and molecular stimulations - Lv_2021_Int.J.Biol.Macromol_167_1262
Author(s) : Lv X , Bai R , Yan JK , Huang HL , Huo XK , Tian XG , Zhao XY , Zhang BJ , Zhao WY , Sun CP
Ref : Int J Biol Macromol , 167 :1262 , 2021
Abstract : Carboxylesterase 2 (CES 2), plays a pivotal role in endobiotic homeostasis and xenobiotic metabolism. Protostanes, the major constituents of the genus Alisma, display a series of pharmacological activities. Despite the extensive studies of pharmacological activities, the investigation on inhibitory effects of protostanes against CES 2 is rarely reported. In this study, the inhibitory activities of a library of protostanes (1-25) against human CES 2 were investigated for the first time, using 6,8-dichloro-9,9-dimethyl-7-oxo-7,9-dihydroacridin-2-yl benzoate (DDAB) as the specific fluorescent probe for human CES 2. Compounds 1, 2, 7, 8, 12, 13, 18, 19, and 25 showed strong inhibitory effects towards CES 2. For the most potent compounds 1, 7, 13, and 25, the inhibition kinetics were further investigated, and these four protostanes were all uncompetitive inhibitors against human CES 2 with the inhibition constant (K(i)) values ranging from 0.89 microM to 2.83 microM. In addition, molecular docking and molecular dynamics stimulation were employed to analyze the potential interactions between these protostanes and CES 2, and amino acid residue Gln422 was identified to play a crucial role in the strong inhibition of protostanes towards CES 2.
ESTHER : Lv_2021_Int.J.Biol.Macromol_167_1262
PubMedSearch : Lv_2021_Int.J.Biol.Macromol_167_1262
PubMedID: 33189757

Title : Enhanced Platelet Response to Clopidogrel in Zucker Diabetic Fatty Rats due to Impaired Clopidogrel Inactivation by Carboxylesterase 1 and Increased Exposure to Active Metabolite - Yao_2019_Drug.Metab.Dispos_47_794
Author(s) : Yao H , Bai R , Ren T , Wang Y , Gu J , Guo Y
Ref : Drug Metabolism & Disposition: The Biological Fate of Chemicals , 47 :794 , 2019
Abstract : Clopidogrel (Clop), a thienopyridine antiplatelet prodrug, is metabolized by cytochrome P450s (CYPs) to an active metabolite, Clop-AM, and hydrolyzed by carboxylesterase (CES)1 to the inactive Clop-acid. Patients with type 2 diabetes (T2DM) tend to have a poor response to Clop due to reduced generation of Clop-AM. Whether a similar response occurs in the Zucker diabetic fatty (ZDF) rat, a commonly used animal model of T2DM, has not been explored. In this work, we compared ZDF and control rats for hepatic CES1- and CYP-mediated Clop metabolism; pharmacokinetics of Clop, Clop-AM, and Clop-acid; and the antiplatelet efficacy of Clop. In contrast to clinical findings, Clop-treated ZDF rats displayed significantly less (50%) maximum platelet aggregation at 4 hours than control rats; the enhanced efficacy was accompanied by higher formation of Clop-AM and lower formation of Clop-acid. In vitro studies showed that hepatic levels of CES1 protein and activity and Ces1e mRNA were significantly lower in ZDF than in control rats, as were the mRNA levels of CYP2B1/2, CYP2C11, and CYP3A2, and levels of CYP2B6-, CYP2C19-, and CYP3A4-related proteins and enzymatic activities in liver microsomes of ZDF rats. Interestingly, liver microsomes of ZDF rats produced higher levels of Clop-AM than that of control rats despite their lower CYP levels, although the addition of fluoride ion, an esterase inhibitor, enhanced Clop-AM formation in control rats more than in ZDF rats. These results suggest that the reduction in CES1-based Clop inactivation indirectly enhances Clop efficacy in ZDF rats by making more Clop available for CYP-mediated Clop-AM formation.
ESTHER : Yao_2019_Drug.Metab.Dispos_47_794
PubMedSearch : Yao_2019_Drug.Metab.Dispos_47_794
PubMedID: 31092394
Gene_locus related to this paper: ratno-Ces1d

Title : A natural inhibitor from Alisma orientale against human carboxylesterase 2: Kinetics, circular dichroism spectroscopic analysis, and docking simulation - Yi_2019_Int.J.Biol.Macromol_133_184
Author(s) : Yi J , Bai R , An Y , Liu TT , Liang JH , Tian XG , Huo XK , Feng L , Ning J , Sun CP , Ma XC , Zhang HL
Ref : Int J Biol Macromol , 133 :184 , 2019
Abstract : As a part of our searching for natural human carboxylesterase 2 (human CES 2) inhibitors from traditional Chinese medicine, we found that the extract of Alisma orientale significantly inhibited human CES 2 in vitro. The investigation on A. orientale led to the isolation of a new protostane-type triterpenoid alismanin I (1). Its structure was determined according to HRESIMS, 1D and 2D NMR spectra. Alismanin I (1) displayed significantly inhibitory activity against human CES 2 with IC50 value of 1.31+/-0.09muM assayed by human CES 2-mediated DDAB hydrolysis. According to its inhibition kinetic result, compound 1 was a noncompetitive type inhibitor, and its Ki was 3.65muM. Its inhibitory effect was confirmed in living cell level through a visual manner. The potential interaction mechanism of compound 1 with human CES 2 was also analyzed by circular dichroism (CD) spectrum and molecular docking.
ESTHER : Yi_2019_Int.J.Biol.Macromol_133_184
PubMedSearch : Yi_2019_Int.J.Biol.Macromol_133_184
PubMedID: 30991064