Publications by authors named "Xiaohua Liu"

605 Publications

Zinc‑finger E‑box‑binding homeobox 1 alleviates acute kidney injury by activating autophagy and the AMPK/mTOR pathway.

Mol Med Rep 2021 Jun 13;23(6). Epub 2021 Apr 13.

Department of Critical Care Medicine, The First Affiliated Hospital of Shandong First Medical University (Shandong Provincial Qianfoshan Hospital), Jinan, Shandong 250014, P.R. China.

Zinc‑finger E‑box‑binding homeobox 1 (ZEB1) is involved in epithelial‑mesenchymal transition. In the present study, the protective effect of ZEB1 on acute kidney injury (AKI) was explored. The cecal ligation and puncture (CLP) method was performed to establish the AKI model in rats. ZEB1 expression, blood urea nitrogen (BUN) and serum creatinine (SCr) levels, inflammation [interleukin (IL)‑1β, IL‑6, and tumour necrosis factor‑α], phosphorylated AMP‑activated protein kinase (p‑AMPK) and phosphorylated mammalian target of rapamycin (p‑mTOR) expression, and histopathological changes in CLP‑induced AKI rats were assessed. AMPK inhibitor dorsomorphin (DM) was intraperitoneally injected to determine the effect of ZEB1 on AKI and the regulatory mechanism involving the AMPK/mTOR pathway. CLP downregulated ZEB1 expression, increased BUN and SCr levels, promoted inflammation and apoptosis, and increased the acute kidney score in the kidney tissues of CLP‑induced AKI rats. Autophagy and the AMPK/mTOR pathway were blocked in CLP‑induced AKI rats. ZEB1 overexpression inhibited inflammation and apoptosis, reduced BUN and SCr levels, and activated autophagy and the AMPK/mTOR pathway in CLP‑induced AKI rats. The protective effect of ZEB1 overexpression on AKI was reversed by DM. Thus, ZEB1 was revealed to alleviate CLP‑induced AKI by activating autophagy and the AMPK/mTOR pathway.
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http://dx.doi.org/10.3892/mmr.2021.12082DOI Listing
June 2021

Multifunctional peptide-conjugated nanocarriers for pulp regeneration in a full-length human tooth root.

Acta Biomater 2021 Apr 1. Epub 2021 Apr 1.

Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX 75246, USA. Electronic address:

Dental pulp is a highly vascularized tissue, situated in an inextensible environment surrounded by rigid dentinal walls. The pulp receives its blood supply solely from the small apical foramen of a tooth root. Due to the unique anatomy that controls nutrition supply, regeneration of pulp tissue in a full-length tooth root has long been a challenge in regenerative endodontics. In this study, we designed and synthesized a multifunctional peptide-conjugated, pH-sensitive, non-viral gene vector for fast revascularization and pulp regeneration in a full-length human tooth root. The multifunctional peptide was designed to have distinctive features, including a cell-penetrating peptide to enhance cellular uptake, a nuclear localization signal peptide to assist in the translocation of an angiogenic gene into the nucleus, and a fluorescent tryptophan residue to visualize and quantify the transfection efficiency. Furthermore, a pH-sensitive dimethylmaleic anhydride (DMA) was integrated with the multifunctional peptide to enhance the transfected gene complex to escape from endosomes/lysosomes after internalization. In vitro experiments showed that the multifunctional non-viral gene vector significantly increased internalization and gene transfection efficiency as well as reduced cytotoxicity. After dental pulp stem cells (DPSCs) were transfected with the multifunctional gene vector/pVEGF complexes, the expression of VEGF from the DPSCs was upregulated for more than eight folds, which in turn greatly enhanced endothelial cell migration and vascular-like tube formation. Six weeks after implantation, the VEGF-transfected DPSCs accelerated new blood vessel formation and the regenerated pulp tissue occupied most of the area in the canal of a full-length human tooth root. The multifunctional peptide conjugated non-viral gene delivery is a safe and effective approach for regenerative endodontics. STATEMENT OF SIGNIFICANCE: Pulp regeneration in a full-length tooth root canal has long been a challenge in regenerative endodontics. This is due to the unique root anatomy that allows the blood supply of the tooth root only from a small apical foramen (< 1 mm), leading to a severe barrier for revascularization during pulp regeneration. In this work, we designed a multifunctional peptide-conjugated, pH-sensitive, non-viral gene vector to address this challenge. Our work shows that the peptide-conjugated system was an excellent carrier for fast revascularization and pulp tissue regeneration in a full-length toot root. This study will interest the multidisciplinary readership in gene delivery, biomaterials, and dental/craniofacial tissue engineering community.
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http://dx.doi.org/10.1016/j.actbio.2021.03.059DOI Listing
April 2021

Glass Flow Evolution and the Mechanism of Antireflective Nanoprotrusion Arrays in Nanoholes by Direct Thermal Imprinting.

ACS Appl Mater Interfaces 2021 Apr 31;13(14):16968-16977. Epub 2021 Mar 31.

Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering, College of Mechatronics and Control Engineering, Shenzhen University, Shenzhen 518060, China.

Moth-eye-mimicking nanoprotrusion arrays are typical bioinspired broadband antireflection patterns that improve the transmittance and visibility of optical devices by adjusting different geometrical parameters of nanostructures, such as diameter, height, shape, and periodic arrangement, and widely used in solar cells, electronic displays, and so on. Rapid, net-shape, less complicated, and low-cost fabrication of the glass-based moth-eye nanostructure array is a huge challenge. This work adopted the nanohole array template to transform the moth-eye nanostructures on the optical glass by hot embossing combined with ultrasonic-assisted demolding. To investigate the mode transition and filling behavior of the glass nanostructures when compressed into the nanoholes, we conducted a series of hot embossing tests with various processing parameters and characterized the geometrical morphology of the glass-based nanostructure array, such as height and shape. In these tests, surface defects such as nanocracks will occur when inappropriate processing parameters were applied and we evaluated the transmittance performance of defective and fine glass nanostructures and surface with no nanostructures to reveal the effect of nanostructures with different levels of quality on antireflection. This work provides an effective and environmental-friendly method for the fabrication of moth-eye nanostructure arrays with an improved antireflection performance.
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http://dx.doi.org/10.1021/acsami.0c22133DOI Listing
April 2021

Event-Triggered Resilient L∞ Control for Markov Jump Systems Subject to Denial-of-Service Jamming Attacks.

IEEE Trans Cybern 2021 Mar 23;PP. Epub 2021 Mar 23.

In this article, the event-triggered resilient L∞ control problem is concerned for the Markov jump systems in the presence of denial-of-service (DoS) jamming attacks. First, a fixed lower bound-based event-triggering scheme (ETS) is presented in order to avoid the Zeno problem caused by exogenous disturbance. Second, when DoS jamming attacks are involved, the transmitted data are blocked and the old control input is kept by using the zero-order holder (ZOH). On the basis of this process, the effect of DoS attacks on ETS is further discussed. Next, by utilizing the state-feedback controller and multiple Lyapunov functions method, some criteria incorporating the restriction of DoS jamming attacks are proposed to guarantee the L∞ control performance of the event-triggered Markov closed-loop jump system. In particular, the bounded transition rates rather than the exact ones are taken into account. That is appropriate for the practical environment in which transition rates of the Markov process are difficult to measure accurately. Correspondingly, some criteria are proposed to obtain state-feedback gains and event-triggering parameters simultaneously. Finally, we provide two examples to show the effectiveness of the proposed method.
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http://dx.doi.org/10.1109/TCYB.2021.3063244DOI Listing
March 2021

Enantioselective synthesis of 3-substituted 3-amino-2-oxindoles via amination with anilines.

Chemistry 2021 Mar 22. Epub 2021 Mar 22.

Sichuan University, College of Chemistry, 29 Wangjiang Road, Jiuyan Bridge, 610064, Chengdu, CHINA.

A chiral N,N' -dioxide-nickel(II) complex-catalyzed asymmetric amination reaction of 3-bromo-3-substituted oxindoles with anilines was developed. A series of alkyl or aryl 3-amino-indolinones with quaternary stereocenters were obtained in high yields with excellent ee values in one step (up to 99% yield, up to 96% ee). The method provided a readily route to optically active intermediates of 3-amino-2-oxindole-based bioactive compounds. Besides, a possible transition state model was proposed to elucidate the origin of the chirality induction based on the X-ray crystal structure of the catalyst and the adduct.
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http://dx.doi.org/10.1002/chem.202100829DOI Listing
March 2021

Development of hedgehog pathway inhibitors by epigenetically targeting GLI through BET bromodomain for the treatment of medulloblastoma.

Acta Pharm Sin B 2021 Feb 21;11(2):488-504. Epub 2020 Jul 21.

CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica (SIMM), Chinese Academy of Sciences, Shanghai 201203, China.

Medulloblastoma (MB) is a common yet highly heterogeneous childhood malignant brain tumor, however, clinically effective molecular targeted therapy is lacking. Modulation of hedgehog (HH) signaling by epigenetically targeting the transcriptional factors GLI through bromodomain-containing protein 4 (BRD4) has recently spurred new interest as potential treatment of HH-driven MB. Through screening of current clinical BRD4 inhibitors for their inhibitory potency against glioma-associated oncogene homolog (GLI) protein, the BRD4 inhibitor was selected as the lead for further structural optimization, which led to the identification of compounds and as the high potency HH inhibitors. Mechanism profiling showed that both compounds suppressed HH signaling by interacting with the transcriptional factor GLI, and were equally potent against the clinical resistant mutants and the wild type of smoothened (SMO) receptor with IC values around 1 nmol/L. In the resistant MB allograft mice, compound was well tolerated and markedly suppressed tumor growth at both 5 mg/kg (TGI = 83.3%) and 10 mg/kg (TGI = 87.6%) doses. Although further modification is needed to improve the pharmacokinetic (PK) parameters, compound represents an efficacious lead compound of GLI inhibitors, possessing optimal safety and tolerance to fight against HH-driven MB.
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http://dx.doi.org/10.1016/j.apsb.2020.07.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7893122PMC
February 2021

Asymmetric catalytic [4+3] cycloaddition of ortho-quinone methides with oxiranes.

Chem Commun (Camb) 2021 Mar 24;57(24):3018-3021. Epub 2021 Feb 24.

Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.

Catalytic enantioselective [4+3] cycloaddition reaction between o-quinone methides and oxiranes was achieved by using a chiral N,N'-dioxide/Tb complex as the catalyst, affording medium-sized hydrodioxepine derivatives in high yields (up to 99%) with good to excellent diastereo-(up to 94 : 6 dr) and enantioselectivities (up to 97% ee). The topographic steric maps and distribution of the buried volume (% V) of the catalysts via Cavallo's SambVca 2 tool were collected to effectively represent the chiral pocket of metal complexes of chiral N,N'-dioxides.
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http://dx.doi.org/10.1039/d1cc00262gDOI Listing
March 2021

The Chloroplastic Small Heat Shock Protein Gene Is Induced by Various Abiotic Stresses in .

Int J Genomics 2021 3;2021:6652445. Epub 2021 Feb 3.

The Engineering Research Institute of Agriculture and Forestry, Ludong University, 186 Hongqizhong Road, Yantai, Shandong Province, China 264025.

Small heat shock proteins (sHSPs) are a group of chaperone proteins existed in all organisms. The functions of sHSPs in heat and abiotic stress responses in many glycophyte plants have been studied. However, their possible roles in halophyte plants are still largely known. In this work, a putative gene was cloned from . Bioinformatics analyses revealed that encoded a chloroplastic protein with the typical features of sHSPs. Amino acid sequence alignment and phylogenetic analysis demonstrated that KvHSP26 shared 30%-77% homology with other sHSPs from Arabidopsis, cotton, durian, salvia, and soybean. Quantitative real-time PCR (qPCR) assays exhibited that was constitutively expressed in different tissues such as leaves, stems, and roots, with a relatively higher expression in leaves. Furthermore, expression of was strongly induced by salt, heat, osmotic stress, and ABA in . All these results suggest that encodes a new sHSP, which is involved in multiple abiotic stress responses in , and it has a great potential to be used as a candidate gene for the breeding of plants with improved tolerances to various abiotic stresses.
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http://dx.doi.org/10.1155/2021/6652445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7875624PMC
February 2021

Triptonide is a reversible non-hormonal male contraceptive agent in mice and non-human primates.

Nat Commun 2021 02 23;12(1):1253. Epub 2021 Feb 23.

Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA.

There are no non-hormonal male contraceptives currently on the market despite decades of efforts toward the development of "male pills". Here, we report that triptonide, a natural compound purified from the Chinese herb Tripterygium Wilfordii Hook F displays reversible male contraceptive effects in both mice and monkeys. Single daily oral doses of triptonide induces deformed sperm with minimal or no forward motility (close to 100% penetrance) and consequently male infertility in 3-4 and 5-6 weeks in mice and cynomolgus monkeys, respectively. Male fertility is regained in ~4-6 weeks after cessation of triptonide intake in both species. Either short- or long-term triptonide treatment causes no discernable systematic toxic side effects based on histological examination of vital organs in mice and hematological and serum biochemical analyses in monkeys. Triptonide appears to target junction plakoglobin and disrupts its interactions with SPEM1 during spermiogenesis. Our data further prove that targeting late spermiogenesis represents an effective strategy for developing non-hormonal male contraceptives.
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http://dx.doi.org/10.1038/s41467-021-21517-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7902613PMC
February 2021

Association between body mass index and risk of cardiovascular disease-specific mortality among adults with hypertension in Shanghai, China.

Aging (Albany NY) 2021 02 17;13(5):6866-6877. Epub 2021 Feb 17.

Department of Biostatistics, School of Public Health, Fudan University, Shanghai, People's Republic of China.

The aim of our study was to examine the association between body mass index (BMI) and the risk of cardiovascular disease (CVD)-specific mortality among Chinese adults with hypertension by sex. This study included 212,394 adult hypertensive patients aged 20-85 years registered in the records of Minhang District during 2007-2018. Cox proportional hazards regression was performed to evaluate the association between BMI and CVD-specific mortality among Chinese adults with hypertension. There were 14,029 deaths over an average of 8.24 years (range, 0.19-11.96 years). The multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) across BMI categories (< 18.5 kg/m, 18.5-24.9 kg/m [reference group], 25.0-29.9 kg/m, and ≥ 30 kg/m) for CVD-specific mortality were 1.37 (1.22-1.53), 1.00 (reference), 0.95 (0.90-1.01), and 1.21 (1.04-1.40) in males, and 1.44 (1.31-1.59), 1.00 (reference), 0.96 (0.91-1.01), and 1.04 (0.92-1.17) in females. A U-shaped relationship was observed between BMI and CVD-specific mortality (overall association < 0.001; non-linearity < 0.001). This association was attenuated in old age. This study revealed a U-shaped relationship between BMI and CVD-specific mortality among hypertensive men and women. In older people, overweight and obesity are potential factors that reduce the risk of CVD death.
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http://dx.doi.org/10.18632/aging.202543DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7993713PMC
February 2021

Enantioselective [4 + 2] Cycloaddition/Cyclization Cascade Reaction and Total Synthesis of -Bis(cyclotryptamine) Alkaloids.

Org Lett 2021 Mar 23;23(5):1856-1861. Epub 2021 Feb 23.

Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.

The asymmetric catalytic synthesis of 3-cyclotryptamine substituted oxindoles through formal [4 + 2] cycloaddition/cyclization cascade is described. A wide range of cyclotryptamine derivatives were obtained in enantioenriched form under mild reaction conditions and were found to have potential anticancer activity. The strategy enables ready assembly of cyclotryptamine subunits at the C-C positions with two quaternary stereogenic centers in -selectivity, leading to the concise synthesis of optically active -bis(hexahydropyrroloindole) and others of the cyclotryptamine alkaloid family.
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http://dx.doi.org/10.1021/acs.orglett.1c00260DOI Listing
March 2021

A novel clinical model for predicting malignancy of solitary pulmonary nodules: a multicenter study in chinese population.

Cancer Cell Int 2021 Feb 17;21(1):115. Epub 2021 Feb 17.

State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, 651 Dongfeng Road East, 510060, Guangzhou, People's Republic of China.

Background: This study aimed to establish and validate a novel clinical model to differentiate between benign and malignant solitary pulmonary nodules (SPNs).

Methods: Records from 295 patients with SPNs in Sun Yat-sen University Cancer Center were retrospectively reviewed. The novel prediction model was established using LASSO logistic regression analysis by integrating clinical features, radiologic characteristics and laboratory test data, the calibration of model was analyzed using the Hosmer-Lemeshow test (HL test). Subsequently, the model was compared with PKUPH, Shanghai and Mayo models using receiver-operating characteristics curve (ROC), decision curve analysis (DCA), net reclassification improvement index (NRI), and integrated discrimination improvement index (IDI) with the same data. Other 101 SPNs patients in Henan Tumor Hospital were used for external validation cohort.

Results: A total of 11 variables were screened out and then aggregated to generate new prediction model. The model showed good calibration with the HL test (P = 0.964). The AUC for our model was 0.768, which was higher than other three reported models. DCA also showed our model was superior to the other three reported models. In our model, sensitivity = 78.84%, specificity = 61.32%. Compared with the PKUPH, Shanghai and Mayo models, the NRI of our model increased by 0.177, 0.127, and 0.396 respectively, and the IDI changed - 0.019, -0.076, and 0.112, respectively. Furthermore, the model was significant positive correlation with PKUPH, Shanghai and Mayo models.

Conclusions: The novel model in our study had a high clinical value in diagnose of MSPNs.
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http://dx.doi.org/10.1186/s12935-021-01810-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7890629PMC
February 2021

Catalytic Asymmetric Homologation of Ketones with α-Alkyl α-Diazo Esters.

J Am Chem Soc 2021 Feb 28;143(5):2394-2402. Epub 2021 Jan 28.

Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China.

The homologation of ketones with diazo compounds is a useful strategy to synthesize one-carbon chain-extended acyclic ketones or ring-expanded cyclic ketones. However, the asymmetric homologation of acyclic ketones with α-diazo esters remains a challenge due to the lower reactivity and complicated selectivity. Herein, we report the enantioselective catalytic homologation of acetophenone and related derivatives with α-alkyl α-diazo esters utilizing a chiral scandium(III) ,'-dioxide as the Lewis acid catalyst. This reaction supplies a highly chemo-, regio-, and enantioselective pathway for the synthesis of optically active β-keto esters with an all-carbon quaternary center through highly selective alkyl-group migration of the ketones. Moreover, the ring expansion of cyclic ketones was accomplished under slightly modified conditions, affording a series of enantioenriched cyclic β-keto esters. Density functional theory calculations have been carried out to elucidate the reaction pathway and possible working models that can explain the observed regio- and enantioselectivity.
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http://dx.doi.org/10.1021/jacs.0c12683DOI Listing
February 2021

Predictive Value of a Thyroid-Absorbed Dose with a Shorter Effective Half-Life on Efficacy in Graves Disease Patients Receiving Iodine-131 Therapy.

Med Sci Monit 2021 Jan 26;27:e928796. Epub 2021 Jan 26.

Department of Nuclear Medicine, Tianjin Medical University General Hospital, Tianjin, China (mainland).

BACKGROUND Although radioiodine therapy (RIT) efficacy is thoroughly validated for Graves disease (GD), there is a lack of research on the predictive factors of RIT, especially the optimal thyroid-absorbed dose (TD) with a shorter effective half-life (Teff ≤5 days). The goal of this study was to explore the predictive value of TD in GD patients receiving RIT with a shorter Teff. MATERIAL AND METHODS We studied 208 GD patients receiving RIT with a shorter Teff. Plotting the receiver-operating characteristic (ROC) curve verified the accuracy of TD for predicting RIT efficacy in GD patients. In addition, we conducted univariate and multivariate analyses to investigate the influence of 14 factors, including thyroid weight, TD, 24-h radioiodine uptake rate (RAIU), the highest RAIU, thyrotrophin receptor antibody level, thyroglobulin antibody level, thyroid peroxidase antibody level, and others, on curative effects of RIT. RESULTS Of the 208 study participants, complete remission and the total effectiveness rates were 68.3% and 92.3%, respectively. The threshold value of TD to predict RIT efficacy was 70.2 Gy, based on ROC analysis. Univariate analysis showed that 24-h RAIU, Teff, total iodine dose, iodine dose per gram of thyroid tissue, TD, and thyrotropin receptor antibody level were significantly associated with RIT efficacy. Multivariate analysis indicated that 24-h RAIU, total iodine dose, iodine dose per gram of thyroid tissue, and TD were significant independent predictors of RIT efficacy. CONCLUSIONS Predicting RIT efficacy from TD with a shorter Teff was feasible in GD patients, and TD above 70.2 Gy had an especially high predictive accuracy.
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http://dx.doi.org/10.12659/MSM.928796DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7847087PMC
January 2021

Osteon: Structure, Turnover, and Regeneration.

Tissue Eng Part B Rev 2021 Mar 8. Epub 2021 Mar 8.

Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, USA.

Bone is composed of dense and solid cortical bone and honeycomb-like trabecular bone. Although cortical bone provides the majority of mechanical strength for a bone, there are few studies focusing on cortical bone repair or regeneration. Osteons (the Haversian system) form structural and functional units of cortical bone. In recent years, emerging evidences have shown that the osteon structure (including osteocytes, lamellae, lacunocanalicular network, and Haversian canals) plays critical roles in bone mechanics and turnover. Therefore, reconstruction of the osteon structure is crucial for cortical bone regeneration. This article provides a systematic summary of recent advances in osteons, including the structure, function, turnover, and regenerative strategies. First, the hierarchical structure of osteons is illustrated and the critical functions of osteons in bone dynamics are introduced. Next, the modeling and remodeling processes of osteons at a cellular level and the turnover of osteons in response to mechanical loading and aging are emphasized. Furthermore, several bioengineering approaches that were recently developed to recapitulate the osteon structure are highlighted. Impact statement This review provides a comprehensive summary of recent advances in osteons, especially the roles in bone formation, remodeling, and regeneration. Besides introducing the hierarchical structure and critical functions of osteons, we elucidate the modeling and remodeling of osteons at a cellular level. Specifically, we highlight the bioengineering approaches that were recently developed to mimic the hierarchical structure of osteons. We expect that this review will provide informative insights and attract increasing attentions in orthopedic community, shedding light on cortical bone regeneration in the future.
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http://dx.doi.org/10.1089/ten.TEB.2020.0322DOI Listing
March 2021

Corrigendum to "Neurotoxicity and biomarkers of zinc oxide nanoparticles in main functional brain regions and dopaminergic neurons" [Sci. Total Environ. 705 (2020)135809/STOTEN-135809].

Sci Total Environ 2021 Apr 20;765:145120. Epub 2021 Jan 20.

Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China; Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment & Food Safety, Tianjin 300050, China. Electronic address:

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http://dx.doi.org/10.1016/j.scitotenv.2021.145120DOI Listing
April 2021

Acute Exposure of Atmospheric Ultrafine Particles Induced Inflammation Response and Dysregulated TGFβ/Smads Signaling Pathway in ApoE Mice.

Cardiovasc Toxicol 2021 May 21;21(5):410-421. Epub 2021 Jan 21.

Department of Toxicology, Tianjin Institute of Environmental and Operational Medicine, No. 1, Dali Road, Heping District, Tianjin, 300050, China.

Ultrafine particles (UFPs) referred to particular matters with aerosol diameter less than 100 nm. Because of the lightweight and small size, UFPs have become an occupational inhalation risk. The UFPs will be accumulated in the deep lung through inhalation, and then reach into all the organs via circulation system; some UFPs even stay in the brain. As previous study reported, UFPs exposure is usually associated with cardiovascular disease, such as atherosclerosis (AS). In our study, we tried to understand how acute UFP exposure caused the biological dysregulation in atherosclerosis. Acute exposure of UFPs were applied to mice for 6 consecutive days, mice were sacrificed after 3, 5, 7, and 10 days post-exposure. Aorta and serum were collected for histological and biomarkers analysis. Mice aortic adventitial fibroblasts (MAFs) were isolated from mice and used to further study to understand the mechanism of UFPs induced atherosclerosis. Compared to the untreated control, the inflammation responses and nitrate stress were observed after acute exposure of UFPs, with increased IL-6, MCP-1, p47phox, and 3-NT levels in the mice serum. Besides, upregulation of microRNAs: miR-301b-3p and Let-7c-1-3p, and their downstream target: Smad2, Smad3, and TGFβ1 were also observed in mouse aorta after acute exposure of UFPs. Similar results were identified in vitro as well. Acute exposure of UFPs induced the systematic nitrate stress and inflammation responses, along with the changes of vascular permeability. Dysregulated miRNAs and TGFβ/Smads signaling pathway indicated the higher risk of atherosclerosis/vasculature remodeling when exposed to UFPs.
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http://dx.doi.org/10.1007/s12012-021-09633-6DOI Listing
May 2021

Ozone exposure promotes pyroptosis in rat lungs via the TLR2/4-NF-κB-NLRP3 signaling pathway.

Toxicology 2021 Feb 28;450:152668. Epub 2020 Dec 28.

Tianjin Institute of Environmental and Operational Medicine, No. 1 Dali Road, Heping District, Tianjin, 300050, China. Electronic address:

Objective: Ozone has become a major air pollutant in recent years, which leading to a variety of lung diseases. This study aimed to explore the mechanisms of pyroptosis and related signaling pathways in ozone-induced lung injury.

Methods: We exposed 120 Wistar rats to ozone, 20 in each group (half male and half female). Ozone exposure concentrations were 0, 0.12, 0.5, 1.0, 2.0 and 4.0 ppm for 6 h. At the same time, we isolated and cultured type I alveolar epithelial cells, then intervened with high mobility group box 1 protein (HMGB1), hyaluronic acid (HA) and Toll-like receptors 2/4 (TLR2/4) inhibitor. In animal experiments, histopathological experiments, TUNEL, ELISA and biochemical indicators were performed. RT-qPCR and western blot experiments assay were used to detect the expression changes of key factors in relevant signal pathways in vivo and in vitro.

Results: After acute ozone exposure, the levels of lung cell injury indicators in bronchoalveolar lavage fluid (BALF), as well as the levels of inflammatory factors in BALF, blood, and lung tissue were significantly increased. Male rats were more sensitive to ozone exposure. Low-concentration ozone exposure caused mild interstitial inflammation in rat lung tissue. Severe inflammation and pulmonary edema appeared with increases in concentration. ELISA results in BALF showed that HMGB1 and HA expressions increased gradually with the increase of ozone exposure concentration. RT-qPCR and Western blot showed that when ozone concentrations increased above 0.5 ppm, the expression of nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing 3 (NLRP3), cleaved caspase-1, and N-gasdermin D (N-GSDMD) in the lung tissue increased significantly, suggesting that ozone exposure induces pyroptosis. At the same time, it was found that ozone exposure activated the nuclear factor kappa B (NF-κB) signal pathway, and increased the mRNA expressions of Toll-like receptors TLR2/4. The results of cell experiments showed that after the addition of HMGB1 and HA, the expression of NF-κB and pyroptosis related indexes increased in type I alveolar epithelial cells, while the corresponding expression decreased after the addition of TLR2/4 inhibitors.

Conclusion: Ozone exposure causes lung injury in a dose- and gender-dependent manner, and is more severe in males. When injured, the levels of HMGB1 and HA in BALF increased, which interact with TLR 2/4 to activate the downstream NF-κB signaling pathway. Further activating the NLRP3 inflammasome complex and regulating the ozone-induced pyroptosis.
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http://dx.doi.org/10.1016/j.tox.2020.152668DOI Listing
February 2021

Tumor Necrosis Factor-α Variations in Patients With Major Depressive Disorder Before and After Antidepressant Treatment.

Front Psychiatry 2020 7;11:518837. Epub 2020 Dec 7.

Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China.

Tumor necrosis factor-α (TNF-α) had been identified as a key pro-inflammatory cytokine in the pathophysiology of major depressive disorder (MDD) and the mechanism of antidepressant treatment. The primary aim of the present study was to examine the serum TNF-α levels in Chinese inpatients with MDD during the acute phase and to explore the changes in TNF-α levels after effective clinical treatment. Fifty-seven consecutive inpatients with MDD and 30 healthy controls were recruited. The serum TNF-α levels were detected using ELISA. Symptoms of depression were evaluated using the 24-item Hamilton Rating Scale for Depression (HAM-D-24). TNF-α levels and HAM-D-24 scores were assessed at baseline and after 2 and 12 weeks of follow-up. The serum TNF-α levels were higher in the MDD group than in the control group. After 2 and 12 weeks of antidepressant treatment, there were significant improvements in the patients' symptoms and significant decreases in the TNF-α levels. The baseline TNF-α levels significantly correlated with the decreased HAM-D-24 scores, particularly for the depressive symptoms of anxiety/somatization and weight loss. The present findings indicate that depression is accompanied by activation of TNF-α, which also has a predictive value for the antidepressant treatment response in patients with MDD.
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http://dx.doi.org/10.3389/fpsyt.2020.518837DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7750423PMC
December 2020

Potential Therapeutic Effect of Traditional Chinese Medicine on Coronavirus Disease 2019: A Review.

Front Pharmacol 2020 9;11:570893. Epub 2020 Nov 9.

The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang, China.

The Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 has been rapidly spreading globally and has caused worldwide social and economic disruption. Currently, no specific antiviral drugs or clinically effective vaccines are available to prevent and treat COVID-19. Traditional Chinese medicine (TCM) can facilitate syndrome differentiation and treatment according to the clinical manifestations of patients and has demonstrated effectiveness in epidemic prevention and control. In China, TCM intervention has helped to control the epidemic; however, TCM has not been fully recognized worldwide. In this review, we summarize the epidemiology and etiological characteristics of severe acute respiratory syndrome coronavirus 2 and the prevention and treatment measures of COVID-19. Additionally, we describe the application of TCM in the treatment of COVID-19 and the identification of small molecules of TCM that demonstrate anti-coronavirus activity. We also analyze the current problems associated with the recognition of TCM. We hope that, through the contribution of TCM, combined with modern technological research and the support of our international counterparts, COVID-19 can be effectively controlled and treated.
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http://dx.doi.org/10.3389/fphar.2020.570893DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7741169PMC
November 2020

Potential Therapeutic Effect of Traditional Chinese Medicine on Coronavirus Disease 2019: A Review.

Front Pharmacol 2020 9;11:570893. Epub 2020 Nov 9.

The Marine Biomedical Research Institute, Guangdong Medical University, Zhanjiang, China.

The Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 has been rapidly spreading globally and has caused worldwide social and economic disruption. Currently, no specific antiviral drugs or clinically effective vaccines are available to prevent and treat COVID-19. Traditional Chinese medicine (TCM) can facilitate syndrome differentiation and treatment according to the clinical manifestations of patients and has demonstrated effectiveness in epidemic prevention and control. In China, TCM intervention has helped to control the epidemic; however, TCM has not been fully recognized worldwide. In this review, we summarize the epidemiology and etiological characteristics of severe acute respiratory syndrome coronavirus 2 and the prevention and treatment measures of COVID-19. Additionally, we describe the application of TCM in the treatment of COVID-19 and the identification of small molecules of TCM that demonstrate anti-coronavirus activity. We also analyze the current problems associated with the recognition of TCM. We hope that, through the contribution of TCM, combined with modern technological research and the support of our international counterparts, COVID-19 can be effectively controlled and treated.
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http://dx.doi.org/10.3389/fphar.2020.570893DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7741169PMC
November 2020

Identification of Uncommon (a Novel Subtype XVcA2G1c) and as Well as Common Assemblages A and B in Humans in Myanmar.

Front Cell Infect Microbiol 2020 25;10:614053. Epub 2020 Nov 25.

National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Chinese Center for Tropical Diseases Research, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Key Laboratory of Parasite and Vector Biology, MOH, Shanghai, China.

and are two important zoonotic intestinal protozoa responsible for diarrheal diseases in humans and animals worldwide. Feces from infected hosts, water and food contaminated by oocysts and cysts as well as predictors such as poverty have been involved in their transmission. Myanmar is one of the world's most impoverished countries. To date, there are few epidemiological studies of and in humans. To understand the prevalence and genetic characterization of spp. and in humans in Myanmar, a molecular epidemiological investigation of the two protozoa was conducted in four villages of Shan State. 172 fecal specimens were collected from Wa people (one each) and identified for the presence of spp. and by sequence analysis of their respective small subunit ribosomal RNA genes. 1.74% of investigated people were infected with spp.- (n = 2) and (n = 1) while 11.05% infected with -assemblages A (n = 6) and B (n = 13). By sequence analysis of 60-kDa glycoprotein gene, the isolate belonged to a novel subtype XVcA2G1c. DNA preparations positive for were further subtyped. Five of them were amplified and sequenced successfully: different assemblage B sequences (n = 2) at the triosephosphate isomerase (tpi) locus; sub-assemblage AII sequence (n = 1) and identical assemblage B sequences (n = 2) at the β-giardin (bg) locus. This is the first molecular epidemiological study of spp. and in humans in Myanmar at both genotype and subtype levels. Due to unclear transmission patterns and dynamics of spp. and , future research effort should focus on molecular epidemiological investigations of the two parasites in humans and animals living in close contact in the investigated areas, even in whole Myanmar. These data will aid in making efficient control strategies to intervene with and prevent occurrence of both diseases.
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http://dx.doi.org/10.3389/fcimb.2020.614053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724083PMC
November 2020

Catalytic asymmetric formal [3+2] cycloaddition of isatogens with azlactones to construct indolin-3-one derivatives.

Chem Commun (Camb) 2021 Jan 11;57(2):239-242. Epub 2020 Dec 11.

Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, China.

The chiral amide-guanidine-catalyzed asymmetric formal [3+2] cycloaddition of isatogens with azlactones is presented. This strategy provided a facile and feasible route to chiral indolin-3-one derivatives bearing two contiguous tetrasubstituted stereocenters in moderate to good yields with high diastereoselectivities and enantioselectivities. A possible working mode was proposed to elucidate the chiral control of the process.
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http://dx.doi.org/10.1039/d0cc06418aDOI Listing
January 2021

Nanofibrous Tubular Three-Dimensional Platform for Single Dental Pulp Stem Cell Polarization.

ACS Appl Mater Interfaces 2020 Dec 30;12(49):54481-54488. Epub 2020 Nov 30.

Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas 75246, United States.

Dental pulp stem cells (DPSCs) are the primary stem cell source for regenerative endodontics. DPSCs need to undergo a polarization process and retain the permanent polarization status to perform the function of odontoblasts. However, the factors that control DPSC polarization and its underlying mechanism remain unknown. In this study, we established a unique nanofibrous tubular three-dimensional (3D) platform to explore DPSC polarization. The 3D platform has a "clean" background and confines one single DPSC in each microisland of the platform; therefore, it is capable of deciphering any signal that initiates or regulates DPSC polarization. Using the biomimetic platform, we identified that the nanofibrous tubular architecture is the crucial factor to initiate DPSC polarization. Dynamic morphological observation showed that the cellular process of the polarized DPSCs continuously extended and reached a plateau at 72 h. Meanwhile, Golgi apparatus, a cell polarization marker, continuously moved from a juxtanuclear region, passed the nucleus, and eventually settled down at a final position that was a few micrometers away from the nucleus. Inhibition of microfilament and microtubule polymerization demonstrated the indispensable role of cytoskeleton reorganization in modulating DPSC polarization. In addition, cell tension was involved in the regulation of DPSC polarization. The findings of this work expand the in-depth understanding of DPSC polarization, which helps design new bioinspired materials for regenerative endodontics.
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http://dx.doi.org/10.1021/acsami.0c17730DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025693PMC
December 2020

Asymmetric Catalytic Reactions of Donor-Acceptor Cyclopropanes.

Angew Chem Int Ed Engl 2021 Apr 15;60(17):9192-9204. Epub 2020 Dec 15.

Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, China.

Due to the synergistic "push-pull" effect of vicinal electron-donating and electron-withdrawing groups, donor-acceptor (D-A) cyclopropanes have been recognized as one of the most powerful building blocks to generate polyfunctional reactive intermediates after a strain-driven ring cleavage. Enantioselective reactions of D-A cyclopropanes provide an efficient approach to enantioenriched acyclic and cyclic compounds. A number of chiral Lewis/Brønsted acids, transition metals, and organocatalysts have been designed for such transformations, including ring-openings, annulations, and rearrangements. This minireview highlights the developments and new advances in this field and describes new synthetic opportunities offered by these interesting methodologies.
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http://dx.doi.org/10.1002/anie.202006736DOI Listing
April 2021

Comparative studies on the binding interaction of two chiral Ru(II) polypyridyl complexes with triple- and double-helical forms of RNA.

J Inorg Biochem 2021 Jan 4;214:111301. Epub 2020 Nov 4.

Key Lab of Environment-friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan 411105, People's Republic of China; Key Laboratory for Green Organic Synthesis and Application of Hunan Province, Xiangtan University, Xiangtan 411105, People's Republic of China. Electronic address:

Two chiral Ru(II) polypyridyl complexes, Δ-[Ru(bpy)(6-F-dppz)] (Δ-1; bpy = 2,2'-bipyridine, 6-F-dppz = 6-fluorodipyrido[3,2-a:2',3'-c]phenazine) and Λ-[Ru(bpy)(6-F-dppz)] (Λ-1), have been synthesized and characterized as binders for the RNA poly(U)•poly(A)*poly(U) triplex and poly(A)•poly(U) duplex in this work. Analysis of the UV-Vis absorption spectra and fluorescence emission spectra indicates that the binding of intercalating Δ-1 with the triplex and duplex RNA is greater than that of Λ-1, while the binding affinities of the two enantiomers to triplex structure is stronger than that of duplex structure. Fluorescence titrations show that the two enantiomers can act as molecular "light switches" for triple- and double-helical RNA. Thermal denaturation studies revealed that that the two enantiomers are more stable to Watson-Crick base-paired double strand of the triplex than the Hoogsteen base-paired third strand, but their stability and selectivity are different. For Δ-enantiomer, the increase of the thermal stability of the Watson-Crick base-paired duplex (13 °C) is slightly stronger than of the Hoogsteen base-paired strand (10 °C), displaying no obvious selectivity. However, compared to the Hoogsteen base-paired strand (5 °C), the stability of the Λ-enantiomer to the Watson-Crick base-paired duplex (13 °C) is more significant, which has obvious selectivity. The overall increase in viscosity of the RNA-(Λ-1) system and its curve shape are similar to that of the RNA-(Δ-1) system, suggesting that the binding modes of two enantiomers with RNA are intercalation. The obtained results in this work may be useful for understanding the binding differences in chiral Ru(II) polypyridyl complexes toward RNA triplex and duplex.
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http://dx.doi.org/10.1016/j.jinorgbio.2020.111301DOI Listing
January 2021

Acute ozone exposure can cause cardiotoxicity: Mitochondria play an important role in mediating myocardial apoptosis.

Chemosphere 2021 Apr 2;268:128838. Epub 2020 Nov 2.

Tianjin Institute of Environmental and Operational Medicine, No. 1 Dali Road, Heping District, Tianjin, 300050, China. Electronic address:

Objective: To clarify the cardiotoxicity induced by acute exposure to different concentrations of ozone in both gender rats and explore the underlying mechanisms.

Methods: A total of 240 rats were randomly sorted into 6 groups with equal numbers of male and female rats in each group. The rats were subjected to ozone inhalation at concentrations of 0, 0.12, 0.5, 1.0, 2.0 and 4.0 ppm, respectively, for 6 h. After ozone exposure, function indicators, myocardial injury indexes and risk factors of cardiovascular disease in blood were assayed.

Results: High ozone exposure resulted in sustained ventricular tachycardia in male and female rats. Myocardial apoptosis in male rats started from 1.0 ppm ozone, and that in female rats started from 2.0 ppm ozone (p < 0.05). Caspase-9 increased significantly from 0.12 ppm ozone (p < 0.01) in both gender rats, while caspase-3 was initially activated at 0.5 ppm ozone. From 1.0 ppm ozone, mitochondrial cristae and myofilaments dissolved. The ratio of Bcl-2/Bax decreased significantly from 0.12 ppm and MRCC-IV decreased significantly from 2.0 ppm by ozone.

Conclusion: Acute ozone exposure can cause paroxysmal ventricular tachycardia in rats. Moreover, the changes of inflammatory factors in the heart tissues of female and male rats after ozone exposure were greater than those of oxidative stress. This study reported for the first time that 6 h ozone exposure does not cause acute cardiomyocyte necrosis, but promotes cardiomyocyte apoptosis in a mitochondrial-dependent manner. Ozone could regulate caspases-3 dependent cardiomyocyte apoptosis by affecting the balance between caspase-9 and XIAP.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128838DOI Listing
April 2021

Aloperine Exerts Antitumor Effects on Bladder Cancer in vitro.

Onco Targets Ther 2020 13;13:10351-10360. Epub 2020 Oct 13.

Department of Urology, The First Affiliated Hospital of University of South of China, Hengyang, Hunan Province, People's Republic of China.

Background: Human bladder cancer is the most common malignant tumor of the urinary system and one of the 10 most common tumors of the whole body. Although most patients with bladder cancer exhibit a good prognosis with standard treatment, effective therapies for patients with a recurrent or advanced bladder cancer are unavailable. Therefore, highly effective drugs to treat such patients need to be developed. Aloperine (ALO), a natural compound isolated from , has antitumor properties. However, the role of ALO in human bladder cancer remains unclear.

Methods: In the present study, MTT was used to detect the cytotoxic effect of ALO on human BC cell line EJ and human urothelium cell line SV-HUC-1cells. Meanwhile, in order to investigate the effects of ALO on the proliferation, apoptosis, migration, and invasion of BC EJ cells and its mechanism by Cell Counting Kit-8 (CCK-8) assay, immunofluorescence, Hoechst 33342 staining, wound scratch assay, transwell migration and invasion assay, Western blot analysis.

Results: ALO can inhibit the proliferation and invasion of human bladder cancer EJ cells, and is low-toxic to human urothelium cells. Moreover, it can promote cellular apoptosis in vitro. Further analysis demonstrated the involvement of Caspase-dependent apoptosis following ALO treatment. ALO also downregulated the protein expression levels of Ras, p-Raf1 and p-Erk1/2.

Conclusion: ALO is a potential drug for human bladder cancer therapy.
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http://dx.doi.org/10.2147/OTT.S260215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568640PMC
October 2020

The Developmental and Translational Study on Biomarkers and Clinical Characteristics-based Diagnostic and Therapeutic Identification of Major Depressive Disorder: Study Protocol for a Multicenter Randomized Controlled Trial in China.

Neuropsychiatr Dis Treat 2020 9;16:2343-2351. Epub 2020 Oct 9.

Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.

Background: Major depressive disorder (MDD) is a heterogeneous mental disease that encompasses different subtypes and specifiers. Clinically targeted treatments have not been identified yet, although standardized strategies are recommended by several clinical guidelines. The main aim of this study is to respectively identify the precise treatment for three different subtypes of MDD (ie, melancholic, atypical, and anxious).

Methods: An 8-to-12-week, multicenter randomized controlled trial (RCT) with a parallel group design will be conducted to determine the most effective and appropriate treatment. A total of 750 adults diagnosed with MDD will be recruited, categorized into melancholic, atypical or anxious type based on the assessment of the Inventory of Depressive Symptomatology (IDS30) and the Hamilton Anxiety Scale (HAMA), and 1:1 randomly assigned to different intervention groups. Blood draw, EEG test, and MRI scan will be performed at baseline and endpoint. Clinical symptom and side-effects will be evaluated at critical decision points (CDP) including weeks two, four, six, eight, and 12 after treatment. The primary outcome is total score and reduction rate of the 17-Hamilton Depression Rating Scale (17-HDRS). The secondary outcomes include the scores of the Quick Inventory of Depressive Symptomatology-self-report (QIDS-SR), IDS30, HAMA and the Treatment Emergent Symptom Scale (TESS). All the data will be analyzed by SAS software.

Discussion: The study commenced recruitment in August 2017 and is currently ongoing.

Trial Registration: ClinicalTrials.gov Identifier: NCT03219008 (July 17, 2017).
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http://dx.doi.org/10.2147/NDT.S271842DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7553657PMC
October 2020

Biophysical insights into the interaction of two enantiomers of Ru(II) complex [Ru(bpy)(7-CH-dppz)] with the RNA poly(U-A⁎U) triplex.

J Biol Inorg Chem 2020 12 11;25(8):1085-1095. Epub 2020 Oct 11.

Key Lab of Environment-Friendly Chemistry and Application in Ministry of Education, Xiangtan University, Xiangtan, 411105, People's Republic of China.

To determine the factors affecting the stabilization of RNA triple-stranded structure by chiral Ru(II) polypyridyl complexes, a new pair of enantiomers, ∆-[Ru(bpy)(7-CH-dppz)] (∆-1; bpy = 2,2'-bipyridine, 7-CH-dppz = 7-methyl-dipyrido[3,2-a,2',3'-c]phenazine) and Λ-[Ru(bpy)(7-CH-dppz)] (Λ-1), have been synthesized and characterized in this work. Binding properties of the two enantiomers with the RNA poly(U-A⁎U) triplex (where "-" denotes the Watson - Crick base pairing and "⁎" denotes the Hoogsteen base pairing) have been studied by spectroscopy and hydrodynamics methods. Under the conditions used in this study, changes in absorption spectra of the two enantiomers are not very different from each other when bound to the triplex, although the binding affinity of ∆-1 is higher than that of Λ-1. Fluorescence titrations and viscosity experiments give convincing evidence for a true intercalative binding of enantiomers with the triplex. However, melting experiments indicated that the two enantiomers selectively stabilized the triplex. The enantiomer ∆-1 stabilize the template duplex and third-strand of the triplex, while it's more effective for stabilization of the template duplex. In stark contrast to ∆-1, Λ-1 stabilizes the triplex without any effect on the third-strand stabilization, suggesting this one extremely prefers to stabilize the template duplex rather than third-strand. Besides, the triplex stabilization effect of ∆-1 is more marked in comparison with that of Λ-1. The obtained results suggest that substituent effects and chiralities of Ru(II) polypyridyl complexes play important roles in the triplex stabilization. Complexes Λ/Δ-[Ru(bpy)(7-CH-dppz)] (Λ/Δ-1; bpy = 2,2'-bipyridine, 7-CH-dppz = 7-methyl-dipyrido[3,2-a,2',3'-c]phenazine) were prepared as stabilizers for poly(U-A ∗ U) triplex. Results suggest the triplex stabilization depends the chiral structures of Λ/Δ-1, indicating that [Ru(bpy)(7-CH-dppz)] is a non-specific intercalator for poly(U-A ∗ U) investigated in this work.
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http://dx.doi.org/10.1007/s00775-020-01825-9DOI Listing
December 2020