Publications by authors named "Qiaojun Fang"

53 Publications

A comprehensive assessment of the biocompatibility of Magnetospirillum gryphiswaldense MSR-1 bacterial magnetosomes in vitro and in vivo.

Toxicology 2021 Sep 14:152949. Epub 2021 Sep 14.

Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing, 100190, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing, 100190, China. Electronic address:

Bacterial magnetosomes (BMs) are iron oxide nanoparticles synthesized naturally by magnetotactic bacteria, made up of nano-sized inorganic crystals enclosed by a lipid bilayer membrane. Due to several superior characteristics, such as the narrow size distribution, uniform morphology, high purity and crystallinity, single magnetic domain as well as easy surface modification, increasing biomedical and biotechnological applications of BMs have been developed. The attracted wide attentions raise the urge for the evaluation of safety and toxicity. In this work, we performed a rather comprehensive and systematic assessment of in vitro and in vivo toxicity of BMs from MSR-1, including the cytotoxicity, mice bodyweights, blood test, organ coefficients, inflammation, and hemocompatibility study. We found that BMs have good biocompatibility except for influences on the immune response as demonstrated by enhanced activation of the complement system and inhibition of lymphocyte proliferation when used with an excessive concentration. BMs induced the production of reactive oxygen species (ROS) in macrophages at a dose-dependent manner but did not cause cell membrane damage and cell cycle arrest until the concentration is approximately 40 times the clinical dosage. We anticipate our work will guide modifications of BMs and expand their future applications.
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http://dx.doi.org/10.1016/j.tox.2021.152949DOI Listing
September 2021

Protein biomarkers in breast cancer-derived extracellular vesicles for use in liquid biopsies.

Am J Physiol Cell Physiol 2021 09 8. Epub 2021 Sep 8.

Lab of Theoretical and Computational Nanoscience, CAS Key Lab of Nanophotonic Materials and Devices, CAS Key Lab of Standardization & Measurement for Nanotechnology, CAS Ctr for Excellence in Nanoscience, Beijing Key Lab of Ambient Particles Health Effects & Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing, China.

Breast cancer is the most common malignant disease in women worldwide. Early diagnosis and treatment can greatly improve the management of breast cancer. Liquid biopsies are becoming convenient detection methods for diagnosing and monitoring breast cancer due to their non-invasiveness and ability to provide real-time feedback. A range of liquid biopsy markers, including circulating tumor proteins, circulating tumor cells, and circulating tumor nucleic acids, have been implemented for breast cancer diagnosis and prognosis, with each having its own advantages and limitations. Circulating extracellular vesicles are messengers of intercellular communication that are packed with information from mother cells and are found in a wide variety of bodily fluids; thus, they are emerging as ideal candidates for liquid biopsy biomarkers. In this review, we summarize extracellular vesicle protein markers that can be potentially used for the early diagnosis and prognosis of breast cancer or determining its specific subtypes.
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http://dx.doi.org/10.1152/ajpcell.00048.2021DOI Listing
September 2021

CD151 enrichment in exosomes of luminal androgen receptor breast cancer cell line contributes to cell invasion.

Biochimie 2021 Jun 23;189:65-75. Epub 2021 Jun 23.

Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing, 100190, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Sino-Danish Center for Education and Research, University of Chinese Academy of Sciences, Beijing, 100190, PR China. Electronic address:

Breast cancer is the most common and highly heterogeneous disease in women worldwide. Given the challenges in the treatment of advanced metastatic breast cancer, it is necessary to understand the molecular mechanisms related to disease progression. Exosomes play various roles in the progression of tumors, including promoting the invasion and advancing the distant metastasis. To study the molecular mechanisms related to the progression of luminal androgen receptor (LAR) breast cancer, we first isolated exosomes of MDA-MB-453 cells, a representative cell line of LAR. Through quantitative proteomic analysis, we identified 180 proteins specifically enriched in exosomes after comparing with those in cells, microvesicles, and the 150K supernatant. Among these, CD151, a protein involved in the regulation of cell motility was the most enriched one. CD151-knockdown exosomes reduced the invasion ability of the recipient breast cancer cell and lowered the phosphorylation level of tyrosine-protein kinase Lck, indicating that the invasion of LAR breast cancer may be due to CD151-enriched exosomes. Our work reports for the first time that CD151 was highly abundant in the exosomes of MDA-MB-453 cells and expands the understanding of the development process of LAR subtype, suggesting CD151 may be a potential candidate for the treatment of LAR breast cancer.
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http://dx.doi.org/10.1016/j.biochi.2021.06.007DOI Listing
June 2021

Biocompatibility of Bacterial Magnetosomes as MRI Contrast Agent: A Long-Term In Vivo Follow-Up Study.

Nanomaterials (Basel) 2021 May 7;11(5). Epub 2021 May 7.

Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China.

Derived from magnetotactic bacteria (MTB), magnetosomes consist of magnetite crystals enclosed within a lipid bilayer membrane and are known to possess advantages over artificially synthesized nanoparticles because of the narrow size distribution, uniform morphology, high purity and crystallinity, single magnetic domain, good biocompatibility, and easy surface modification. These unique properties have increasingly attracted researchers to apply bacterial magnetosomes (BMs) in the fields of biology and medicine as MRI imaging contrast agents. Due to the concern of biosafety, a long-term follow-up of the distribution and clearance of BMs after entering the body is necessary. In this study, we tracked changes of BMs in major organs of mice up to 135 days after intravenous injection using a combination of several techniques. We not only confirmed the liver as the well-known targeted organs of BMs, but also found that BMs accumulated in the spleen. Besides, two major elimination paths, as well as the approximate length of time for BMs to be cleared from the mice, were revealed. Together, the results not only confirm that BMs have high biocompatibility, but also provide a long-term in-vivo assessment which may further help to forward the clinical applications of BMs as an MRI contrast agent.
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http://dx.doi.org/10.3390/nano11051235DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151038PMC
May 2021

Disruption of the autism-related gene Pak1 causes stereocilia disorganization, hair cell loss, and deafness in mice.

J Genet Genomics 2021 04 24;48(4):324-332. Epub 2021 Apr 24.

State Key Laboratory of Bioelectronics, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, Jiangsu 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, China; Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing 100864, China; Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing 100069, China. Electronic address:

Several clinical studies have reported that hearing loss is correlated with autism in children. However, little is known about the underlying mechanism between hearing loss and autism. p21-activated kinases (PAKs) are a family of serine/threonine kinases that can be activated by multiple signaling molecules, particularly the Rho family of small GTPases. Previous studies have shown that Pak1 mutations are associated with autism. In the present study, we take advantage of Pak1 knockout (Pak1) mice to investigate the role of PAK1 in hearing function. We find that PAK1 is highly expressed in the postnatal mouse cochlea and that PAK1 deficiency leads to hair cell (HC) apoptosis and severe hearing loss. Further investigation indicates that PAK1 deficiency downregulates the phosphorylation of cofilin and ezrin-radixin-moesin and the expression of βII-spectrin, which further decreases the HC synapse density in the basal turn of cochlea and disorganized the HC stereocilia in all three turns of cochlea in Pak1 mice. Overall, our work demonstrates that the autism-related gene Pak1 plays a crucial role in hearing function. As the first candidate gene linking autism and hearing loss, Pak1 may serve as a potential target for the clinical diagnosis of autism-related hearing loss.
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http://dx.doi.org/10.1016/j.jgg.2021.03.010DOI Listing
April 2021

Siderophores for medical applications: Imaging, sensors, and therapeutics.

Authors:
Di Fan Qiaojun Fang

Int J Pharm 2021 Mar 1;597:120306. Epub 2021 Feb 1.

Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China; Sino-Danish Center for Education and Research, Beijing 101408, PR China. Electronic address:

Siderophores are low-molecular-weight chelators produced by microorganisms to scavenge iron from the environment and deliver it to cells via specific receptors. Tremendous researches on the molecular basis of siderophore regulation, synthesis, secretion, and uptake have inspired their diverse applications in the medical field. Replacing iron with radionuclides in siderophores, such as the most prominent Ga-68 for positron emission tomography (PET), carves out ways for targeted imaging of infectious diseases and cancers. Additionally, the high affinity of siderophores for metal ions or microorganisms makes them a potent detecting moiety in sensors that can be used for diagnosis. As for therapeutics, the notable Trojan horse-inspired siderophore-antibiotic conjugates demonstrate enhanced toxicity against multi-drug resistant (MDR) pathogens. Besides, siderophores can tackle iron overload diseases and, when combined with moieties such as hydrogels and nanoparticles, a wide spectrum of iron-induced diseases and even cancers. In this review, we briefly outline the related mechanisms, before summarizing the siderophore-based applications in imaging, sensors, and therapeutics.
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http://dx.doi.org/10.1016/j.ijpharm.2021.120306DOI Listing
March 2021

A P4 Medicine Perspective of Gut Microbiota and Prediabetes: Systems Analysis and Personalized Intervention.

J Transl Int Med 2020 Sep 25;8(3):119-130. Epub 2020 Sep 25.

Fujian Provincial Key Laboratory of Brain Aging and Neurodegenerative Diseases, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, Fujian Province, China.

Type 2 diabetes (T2D) accounts for approximately 90% of diabetes worldwide and has become a global public health problem. Generally, individuals go to hospitals and get healthcare only when they have obvious T2D symptoms. While the underlying cause and mechanism of the disease are usually not well understood, treatment is for the symptoms, but not for the disease cause, and patients often continue to progress with more symptoms. Prediabetes is the early stage of diabetes and provides a good time window for intervention and prevention. However, with few symptoms, prediabetes is usually ignored without any treatment. Obviously, it is far from ideal to rely on the traditional medical system for diabetes healthcare. As a result, the medical system must be transformed from a reactive approach to a proactive approach. Root cause analysis and personalized intervention should be conducted for patients with prediabetes. Based on systems medicine, also known as P4 medicine, with a predictive, preventive, personalized, and participatory approach, new medical system is expected to significantly promote the prevention and treatment of chronic diseases such as prediabetes and diabetes. Many studies have shown that the occurrence and development of diabetes is closely related to gut microbiota. However, the relationship between diabetes and gut microbiota has not been fully elucidated. This review describes the research on the relationship between gut microbiota and diabetes and some exploratory trials on the interventions of prediabetes based on P4 medicine model. Furthermore, we also discussed how these findings might influence the diagnosis, prevention and treatment of diabetes in the future, thereby to improve the wellness of human beings.
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http://dx.doi.org/10.2478/jtim-2020-0020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7534502PMC
September 2020

Molecular recognition of human islet amyloid polypeptide assembly by selective oligomerization of thioflavin T.

Sci Adv 2020 Aug 5;6(32):eabc1449. Epub 2020 Aug 5.

State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, P. R. China.

Selective oligomerization is a common phenomenon existing widely in the formation of intricate biological structures in nature. The precise design of drug molecules with an oligomerization state that specifically recognizes its receptor, however, remains substantially challenging. Here, we used scanning tunneling microscopy (STM) to identify the oligomerization states of an amyloid probe thioflavin T (ThT) on hIAPP assembly to be exclusively even numbers. We demonstrate that both adhesive interactions between ThT and the protein substrate and cohesive interactions among ThT molecules govern the oligomerization state of the bounded ThT. Specifically, the work of the cohesive interaction between two head/tail ThTs is determined to be 6.4 , around 50% larger than that of the cohesive interaction between two side-by-side ThTs (4.2 ). Overall, our STM imaging and theoretical understanding at the single-molecule level provide valuable insights into the design of drug compounds using the selective oligomerization of molecular probes to recognize protein self-assembly.
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http://dx.doi.org/10.1126/sciadv.abc1449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7406363PMC
August 2020

Drug-internalized bacterial swimmers for magnetically manipulable tumor-targeted drug delivery.

Nanoscale 2020 Jul;12(25):13513-13522

CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China. and Laboratory of Theoretical and Computational Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China and University of Chinese Academy of Sciences, Beijing 100049, China and Sino-Danish Center for Education and Research, Beijing 101408, China and Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Beijing 100190, China.

Tumor-targeted drug carriers are becoming attractive for precise drug delivery in anti-tumor therapy. However, a lot of the reported drug delivery systems are complicatedly designed and their destiny in vivo is beyond our control, which limited their clinical applications. Hence, it is urgently needed to develop spatio-manipulable self-propelled nanosystems for drug delivery in a facile way. Here, we have successfully constructed drug-internalized bacterial swimmers, whose movement can be manually controlled by an external magnetic field (MF). We demonstrate that the swimmers maintain the mobility to align and swim along MF lines. Further studies reveal that the doxorubicin (DOX-) internalized bacterial swimmers are able to navigate toward tumor sites under the guidance of MF, rendering enhanced anti-tumor efficacy compared with that of dead ones and free DOX. Therefore, the MF-guided bacterial swimmers hold great promise for spatio-manipulable drug delivery in precision medicine.
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http://dx.doi.org/10.1039/d0nr01892aDOI Listing
July 2020

A Protein Corona Adsorbed to a Bacterial Magnetosome Affects Its Cellular Uptake.

Int J Nanomedicine 2020 6;15:1481-1498. Epub 2020 Mar 6.

CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China.

Purpose: It is well known that when exposed to human blood plasma, nanoparticles are predominantly coated by a layer of proteins, forming a corona that will mediate the subsequent cell interactions. Magnetosomes are protein-rich membrane nanoparticles which are synthesized by magnetic bacteria; these have gained a lot of attention owing to their unique magnetic and biochemical characteristics. Nevertheless, whether bacterial magnetosomes have a corona after interacting with the plasma, and how such a corona affects nanoparticle-cell interactions is yet to be elucidated. The aim of this study was to characterize corona formation around a bacterial magnetosome and to assess the functional consequences.

Methods: Magnetosomes were isolated from the magnetotactic bacteria, (MSR-1). Size, morphology, and zeta potential were measured by transmission electron microscopy and dynamic light scattering. A quantitative characterization of plasma corona proteins was performed using LC-MS/MS. Protein absorption was further examined by circular dichroism and the effect of the corona on cellular uptake was investigated by microscopy and spectroscopy.

Results: Various serum proteins were found to be selectively adsorbed on the surface of the bacterial magnetosomes following plasma exposure, forming a corona. Compared to the pristine magnetosomes, the acquired corona promoted efficient cellular uptake by human vascular endothelial cells. Using a protein-interaction prediction method, we identified cell surface receptors that could potentially associate with abundant corona components. Of these, one abundant corona protein, ApoE, may be responsible for internalization of the magnetosome-corona complex through LDL receptor-mediated internalization.

Conclusion: Our findings provide clues as to the physiological response to magnetosomes and also reveal the corona composition of this membrane-coated nanomaterial after exposure to blood plasma.
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http://dx.doi.org/10.2147/IJN.S220082DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7065717PMC
May 2020

Three-Dimensional Graphene Enhances Neural Stem Cell Proliferation Through Metabolic Regulation.

Front Bioeng Biotechnol 2019 8;7:436. Epub 2020 Jan 8.

MOE Key Laboratory for Developmental Genes and Human Disease, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Institute of Life Sciences, Southeast University, Nanjing, China.

Graphene consists of two-dimensional sp2-bonded carbon sheets, a single or a few layers thick, which has attracted considerable interest in recent years due to its good conductivity and biocompatibility. Three-dimensional graphene foam (3DG) has been demonstrated to be a robust scaffold for culturing neural stem cells (NSCs) that not only supports NSCs growth, but also maintains cells in a more active proliferative state than 2D graphene films and ordinary glass. In addition, 3DG can enhance NSCs differentiation into astrocytes and especially neurons. However, the underlying mechanisms behind 3DG's effects are still poorly understood. Metabolism is the fundamental characteristic of life and provides substances for building and powering the cell. Metabolic activity is tightly tied with the proliferation, differentiation, and self-renewal of stem cells. This study focused on the metabolic reconfiguration of stem cells induced by culturing on 3DG. This study established the correlation between metabolic reconfiguration metabolomics with NSCs cell proliferation rate on different scaffold. Several metabolic processes have been uncovered in association with the proliferation change of NSCs. Especially, culturing on 3DG triggered pathways that increased amino acid incorporation and enhanced glucose metabolism. These data suggested a potential association between graphene and pathways involved in Parkinson's disease. Our work provides a very useful starting point for further studies of NSC fate determination on 3DG.
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http://dx.doi.org/10.3389/fbioe.2019.00436DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6961593PMC
January 2020

On-Surface Crystallization Behaviors of H-Bond Donor-Acceptor Complexes at Liquid/Solid Interfaces.

Langmuir 2019 Jul 26;35(27):8935-8942. Epub 2019 Jun 26.

Center of Materials Science and Optoelectronics Engineering , University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.

Two-dimensional (2D) crystallization behaviors of A-TPC ( n = 4, 6, 10), T3C, and hydrogen-bonded complexes [email protected] ( n = 4, 6, 10) are investigated by means of scanning tunneling microscope (STM) observations and density functional theory (DFT) calculations. The STM observations reveal that A-TPC, A-TPC, and T3C self-organize into dumbbell-shaped structures, well-ordered bright arrays, and zigzag structures, respectively. Interestingly, [email protected] fails to form the cage-ball structure, whereas [email protected] and [email protected] co-assemble into cage-ball structures with the same lattice parameters. The filling rates of the balls of these two kinds of cage-ball structures depend heavily on the deposition sequence. As a result, the filling rates of the cages in T3C/A-TPC ( n = 4, 6) with deposition of T3C anterior to A-TPC are higher than those in A-TPC /T3C ( n = 4, 6) with the opposite deposition sequence. Furthermore, lattice defects formed by T3C coexist with the cage-ball structures. Moreover, the similar energy per unit area of lattice defects (-0.101 kcal mol Å) and the two cage-ball networks (-0.194 and -0.208 kcal mol Å, respectively), illustrating the similar stabilities of lattice defects and cage-ball networks, demonstrates the rationality of lattice defects. Combining STM investigations and DFT calculations, this work could provide a useful approach to investigate the 2D crystallization mechanisms of supramolecular liquid crystals on surfaces.
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http://dx.doi.org/10.1021/acs.langmuir.9b01350DOI Listing
July 2019

Peptosome Coadministration Improves Nanoparticle Delivery to Tumors through NRP1-Mediated Co-Endocytosis.

Biomolecules 2019 05 5;9(5). Epub 2019 May 5.

CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, Beijing 100190, China.

Improving the efficacy of nanoparticles (NPs) delivery to tumors is critical for cancer diagnosis and therapy. In our previous work, amphiphilic peptide APPA self-assembled nanocarriers were designed and constructed for cargo delivery to tumors with high efficiency. In this study, we explore the use of APPA self-assembled peptosomes as a nanoparticle adjuvant to enhance the delivery of nanoparticles and antibodies to integrin αvβ3 and neuropilin-1 (NRP1) positive tumors. The enhanced tumor delivery of coadministered NPs was confirmed by better magnetosome (Mag)-based T-weighted magnetic resonance imaging (MRI), liposome-based fluorescence imaging, as well as the improved anti-tumor efficacy of monoclonal antibodies (trastuzumab in this case) and doxorubicin (DOX)-containing liposomes. Interestingly, the improvement is most significant for the delivering of compounds that have active or passive tumor targeting ability, such as antibodies or NPs that have enhanced permeability and retention (EPR) effect. However, for non-targeting small molecules, the effect is not significant. In vitro and in vivo studies suggest that both peptosomes and the coadministered compounds might be internalized into cells through a NRP1 mediated co-endocytosis (CoE) pathway. The improved delivery of coadministered NPs and antibodies to tumors suggests that the coadministration with APPA self-assembled peptosomes could be a valuable approach for advancing αvβ3 and NRP1 positive tumors diagnosis and therapy.
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http://dx.doi.org/10.3390/biom9050172DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6572427PMC
May 2019

Single and double boron atoms doped nanoporous CN-h2D electrocatalysts for highly efficient N reduction reaction: a density functional theory study.

Nanotechnology 2019 Aug 26;30(33):335403. Epub 2019 Apr 26.

Institute of Industrial Catalysis, College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.

The electrocatalytical process is the most efficient way to produce ammonia (NH) under ambient conditions, but developing a highly efficient and low-cost metal-free electrocatalysts remains a major scientific challenge. Hence, single atom and double boron (B) atoms doped 2D graphene-like carbon nitride (CN-h2D) electrocatalysts have been designed ([email protected] and [email protected]), and the efficiency of N reduction reaction (NRR) is examined by density functional theory calculation. The results show that the single and double B atoms can both be strongly embedded in natural nanoporous CN with superior catalytic activity for N activation. The reaction mechanisms of NRR on the [email protected] and [email protected] are both following an enzymatic pathway, and [email protected] is a more efficient electrocatalyst with extremely low overpotential of 0.19 eV comparing to [email protected] (0.29 eV). In the low energy region, the hydrogenation of N is thermodynamically more favorable than the hydrogen production, thereby improving the selectivity for NRR. Based on these results, a new double-atom strategy may help guiding the experimental synthesis of highly efficient NRR electrocatalysts.
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http://dx.doi.org/10.1088/1361-6528/ab1d01DOI Listing
August 2019

Fetal bovine serum inhibits neomycin-induced apoptosis of hair cell-like HEI-OC-1 cells by maintaining mitochondrial function.

Am J Transl Res 2019 15;11(3):1343-1358. Epub 2019 Mar 15.

Department of Otolaryngology, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University Nanjing 210008, China.

Aging and exposure to noise or ototoxic drugs are major causes of hair cell death leading to human hearing loss, and many agents have been developed to protect hair cells from apoptosis. Fetal bovine serum (FBS) is a fundamental ingredient in the culture medium of hair cell-like House Ear Institute Organ of Corti 1 (HEI-OC-1) cells, but there have been no reports about the function of FBS in HEI-OC-1 cell apoptosis. In this study, we found that FBS deprivation alone significantly increased HEI-OC-1 cell apoptosis in the absence of neomycin exposure and that the presence of FBS significantly inhibited HEI-OC-1 cell apoptosis after neomycin exposure compared to FBS-deprived cells. Further, we found that the protective effect of FBS was dose dependent and more effective than the growth factors B27, N2, EGF, bFGF, IGF-1, and heparan sulfate. We also found that FBS deprivation significantly disrupted the expression level of mitochondrial proteins, increased pro-apoptotic gene expression, decreased the mitochondrial membrane potential, and increased reactive oxygen species accumulation in HEI-OC-1 cells after neomycin exposure. These findings indicate that FBS is involved in maintaining the level of mitochondrial proteins, maintaining the balance of oxidant gene expression, and preventing the accumulation of ROS, and thus FBS maintains normal mitochondrial function and inhibits apoptosis in HEI-OC-1 cells after neomycin exposure.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6456536PMC
March 2019

Bilayer Adsorption of Porphyrin Molecules Substituted with Carboxylic Acid atop the NN4A Network Revealed by STM and DFT.

Langmuir 2019 Apr 18;35(13):4428-4434. Epub 2019 Mar 18.

CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology (NCNST) , Beijing 100190 , China.

Bottom-up technology is a bridge connecting a two-dimensional (2D) monolayer structure with a three-dimensional (3D) bulk structure. From 2D to 3D, it helps us to understand the driving force of an organization process to control the molecular arrangement in the 3D phase. Here, we aimed at the fabrication of multilayer nanostructures on solid substrates. Bis(3,5-diacidic)diazobenzene (NN4A) was chosen as one molecule because of its photosensitive azo group and carboxylic group possessing hydrogen bonding effect, while porphyrin molecules composed of different numbers and positions of carboxylic acid groups were used as the other component. It was found that the porphyrin molecules could adopt different adsorption configurations because of the influence of carboxylic groups, leading to different subsequent coassemblies on the solid surface. The NN4A/porphyrin systems underwent structural transformation when NN4A molecules were adsorbed on the highly oriented pyrolytic graphite surface with predeposited porphyrin. This work displayed an efficient method on the construction of multilayer nanostructures in the molecular surface engineering and provided a new way to construct 3D structures based on the molecular design.
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http://dx.doi.org/10.1021/acs.langmuir.8b03507DOI Listing
April 2019

Deletion of Limk1 and Limk2 in mice does not alter cochlear development or auditory function.

Sci Rep 2019 03 4;9(1):3357. Epub 2019 Mar 4.

Department of Biomedical Engineering, Southern University of Science and Technology, 518000, Shenzhen, China.

Inherited hearing loss is associated with gene mutations that result in sensory hair cell (HC) malfunction. HC structure is defined by the cytoskeleton, which is mainly composed of actin filaments and actin-binding partners. LIM motif-containing protein kinases (LIMKs) are the primary regulators of actin dynamics and consist of two members: LIMK1 and LIMK2. Actin arrangement is directly involved in the regulation of cytoskeletal structure and the maturation of synapses in the central nervous system, and LIMKs are involved in structural plasticity by controlling the activation of the actin depolymerization protein cofilin in the olfactory system and in the hippocampus. However, the expression pattern and the role of LIMKs in mouse cochlear development and synapse function also need to be further studied. We show here that the Limk genes are expressed in the mouse cochlea. We examined the morphology and the afferent synapse densities of HCs and measured the auditory function in Limk1 and Limk2 double knockout (DKO) mice. We found that the loss of Limk1 and Limk2 did not appear to affect the overall development of the cochlea, including the number of HCs and the structure of hair bundles. There were no significant differences in auditory thresholds between DKO mice and wild-type littermates. However, the expression of p-cofilin in the DKO mice was significantly decreased. Additionally, no significant differences were found in the number or distribution of ribbon synapses between the DKO and wild-type mice. In summary, our data suggest that the Limk genes play a different role in the development of the cochlea compared to their role in the central nervous system.
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http://dx.doi.org/10.1038/s41598-019-39769-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6399249PMC
March 2019

Inhibition of Histone Methyltransferase G9a Attenuates Noise-Induced Cochlear Synaptopathy and Hearing Loss.

J Assoc Res Otolaryngol 2019 06 1;20(3):217-232. Epub 2019 Feb 1.

Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Walton Research Building, Room 403-E, 39 Sabin Street, Charleston, SC, 29425, USA.

Posttranslational modification of histones alters their interaction with DNA and nuclear proteins, influencing gene expression and cell fate. In this study, we investigated the effect of G9a (KMT1C, EHMT2), a major histone lysine methyltransferase encoded by the human EHMT2 gene and responsible for histone H3 lysine 9 dimethylation (H3K9me2) on noise-induced permanent hearing loss (NIHL) in adult CBA/J mice. The conditions of noise exposure used in this study led to losses of cochlear synapses and outer hair cells (OHCs) and permanent auditory threshold shifts. Inhibition of G9a with its specific inhibitor BIX 01294 or with siRNA significantly attenuated these pathological features. Treatment with BIX 01294 also prevented the noise-induced decrease of KCNQ4 immunolabeling in OHCs. Additionally, G9a was increased in cochlear cells, including both outer and inner sensory hair cells, some spiral ganglion neurons (SGNs), and marginal cells, 1 h after the completion of the noise exposure. Also subsequent to noise exposure, immunoreactivity for H3K9me2 appeared in some nuclei of OHCs following a high-to-low frequency gradient with more labeled OHCs in the 45-kHz than the 32-kHz region, as well as in the marginal cells and in some SGNs of the basal turn. These findings suggest that epigenetic modifications of H3K9me2 are involved in NIHL and that pharmacological targeting of G9a may offer a strategy for protection against cochlear synaptopathy and NIHL.
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http://dx.doi.org/10.1007/s10162-019-00714-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513956PMC
June 2019

Mitochondrial Calcium Transporters Mediate Sensitivity to Noise-Induced Losses of Hair Cells and Cochlear Synapses.

Front Mol Neurosci 2018 8;11:469. Epub 2019 Jan 8.

Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC, United States.

Mitochondria modulate cellular calcium homeostasis by the combined action of the mitochondrial calcium uniporter (MCU), a selective calcium entry channel, and the sodium calcium exchanger (NCLX), which extrudes calcium from mitochondria. In this study, we investigated MCU and NCLX in noise-induced hearing loss (NIHL) using adult CBA/J mice and noise-induced alterations of inner hair cell (IHC) synapses in MCU knockout mice. Following noise exposure, immunoreactivity of MCU increased in cochlear sensory hair cells of the basal turn, while immunoreactivity of NCLX decreased in a time- and exposure-dependent manner. Inhibition of MCU activity MCU siRNA pretreatment or the specific pharmacological inhibitor Ru360 attenuated noise-induced loss of sensory hair cells and synaptic ribbons, wave I amplitudes, and NIHL in CBA/J mice. This protection was afforded, at least in part, through reduced cleavage of caspase 9 (CC9). Furthermore, MCU knockout mice on a hybrid genetic CD1 and C57/B6 background showed resistance to noise-induced seizures compared to wild-type littermates. Owing to the CD1 background, MCU knockouts and littermates suffer genetic high frequency hearing loss, but their IHCs remain intact. Noise-induced loss of IHC synaptic connections and reduction of auditory brainstem response (ABR) wave I amplitude were recovered in MCU knockout mice. These results suggest that cellular calcium influx during noise exposure leads to mitochondrial calcium overload MCU and NCLX. Mitochondrial calcium overload, in turn, initiates cell death pathways and subsequent loss of hair cells and synaptic connections, resulting in NIHL.
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http://dx.doi.org/10.3389/fnmol.2018.00469DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6331433PMC
January 2019

Proteomic profiling of RAW264.7 macrophage cells exposed to graphene oxide: insights into acute cellular responses.

Nanotoxicology 2019 02 17;13(1):35-49. Epub 2019 Jan 17.

a CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety , CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology , Beijing , China.

Although the toxicity and molecular mechanisms of graphene oxide (GO) have been reported for several cell types, no proteomic study of GO has yet been conducted on macrophage cells. In this study, we used proteomics based on stable isotope labeling with amino acids in cell culture (SILAC) to quantify the proteomic changes in macrophage RAW 264.7 cells following GO treatment. We found 73 proteins that were significantly dysregulated after GO treatment. The down-regulated proteins included many ribosomal subunit proteins, indicating that GO affected cell growth. The most elevated proteins were lipoprotein lipase (LPL) and lysozyme 1 (LYZ1) which have not been reported before, and both can be used as candidate markers for GO exposure. Further enrichment analysis of the up-regulated proteins indicated these proteins are associated with the integrin complex and membrane rafts, as well as with two signal pathways: the phagosome and steroid biosynthesis pathways. We confirmed a GO concentration-dependent increase in membrane rafts and the production of phagosomes. GO exposure also induced necrotic cell death and an inflammation response in RAW 264.7 cells. We also observed an increase in the oxidative stress response (ROS) and autophagy, and the results suggest that ROS induced autophagy by the ROS-NRF2-P62 pathway.
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http://dx.doi.org/10.1080/17435390.2018.1530389DOI Listing
February 2019

Uncovering the Conduction Behavior of van der Waals Ambipolar Semiconductors.

Adv Mater 2019 Jan 29;31(1):e1805317. Epub 2018 Oct 29.

CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, China.

A long-standing puzzle about van der Waals semiconductors (vdWS) is regarding the origin(s) of the conduction behavior they exhibit. Of particular interest are those with ambipolar conduction, which may provide an alternative choice for practical applications when considering the difficulties of doping the ultrathin bodies of vdWS. Here, the conduction behavior of ambipolar vdWS is analytically and theoretically studied. Using numerical simulation, it is shown that ambipolar vdWS can be fully captured by a Schottky-barrier FET model. Based on this, it is found that the widely observed conduction polarity transition while changing the body thickness mainly comes from the tuning of band alignment at the metal/vdWS interfaces. This transition can be suppressed/inversed by introducing an inert hBN layer between the vdWS and the substrate. Through first-principles calculations, it is demonstrated that metal/vdWS/substrate interactions play a crucial role in tuning the Schottky-barrier heights, which finally determines the conduction behavior that ambipolar vdWS exhibit.
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http://dx.doi.org/10.1002/adma.201805317DOI Listing
January 2019

The role of FOXG1 in the postnatal development and survival of mouse cochlear hair cells.

Neuropharmacology 2019 01 15;144:43-57. Epub 2018 Oct 15.

Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China; Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 211189, China; Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China. Electronic address:

The development of therapeutic interventions for hearing loss requires a detailed understanding of the genes and proteins involved in hearing. The FOXG1 protein plays an important role in early neural development and in a variety of neurodevelopmental disorders. Previous studies have shown that there are severe deformities in the inner ear in Foxg1 knockout mice, but due to the postnatal lethality of Foxg1 knockout mice, the role of FOXG1 in hair cell (HC) development and survival during the postnatal period has not been investigated. In this study, we took advantage of transgenic mice that have a specific knockout of Foxg1 in HCs, thus allowing us to explore the role of FOXG1 in postnatal HC development and survival. In the Foxg1 conditional knockout (CKO) HCs, an extra row of HCs appeared in the apical turn of the cochlea and some parts of the middle turn at postnatal day (P)1 and P7; however, these HCs gradually underwent apoptosis, and the HC number was significantly decreased by P21. Auditory brainstem response tests showed that the Foxg1 CKO mice had lost their hearing by P30. The RNA-Seq results and the qPCR verification both showed that the Wnt, Notch, IGF, EGF, and Hippo signaling pathways were down-regulated in the HCs of Foxg1 CKO mice. The significant down-regulation of the Notch signaling pathway might be the reason for the increased numbers of HCs in the cochleae of Foxg1 CKO mice at P1 and P7, while the down-regulation of the Wnt, IGF, and EGF signaling pathways might lead to subsequent HC apoptosis. Together, these results indicate that knockout of Foxg1 induces an extra row of HCs via Notch signaling inhibition and induces subsequent apoptosis of these HCs by inhibiting the Wnt, IGF, and EGF signaling pathways. This study thus provides new evidence for the function and mechanism of FOXG1 in HC development and survival in mice.
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http://dx.doi.org/10.1016/j.neuropharm.2018.10.021DOI Listing
January 2019

Switchable counterion gradients around charged metallic nanoparticles enable reception of radio waves.

Sci Adv 2018 10 12;4(10):eaau3546. Epub 2018 Oct 12.

CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.

Mechanically flexible, easy-to-process, and environmentally benign materials capable of current rectification are interesting alternatives to "hard" silicon-based devices. Among these materials are metallic/charged-organic nanoparticles in which electronic currents though metal cores are modulated by the gradients of counterions surrounding the organic ligands. Although layers of oppositely charged particles can respond to both electronic and chemical signals and can function even under significant mechanical deformation, the rectification ratios of these "chemoelectronic" elements have been, so far, low. This work shows that significantly steeper counterion gradients and significantly higher rectification ratios can be achieved with nanoparticles of only one polarity but in contact with a porous electrode serving as a counterion "sink." These composite structures act as rectifiers even at radio frequencies, providing a new means of interfacing counterions' dynamics with high-frequency electronic currents.
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http://dx.doi.org/10.1126/sciadv.aau3546DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6184746PMC
October 2018

Quantitative proteomic analysis to the first commercialized liposomal paclitaxel nano-platform Lipusu revealed the molecular mechanism of the enhanced anti-tumor effect.

Artif Cells Nanomed Biotechnol 2018 19;46(sup3):S147-S155. Epub 2018 Sep 19.

a CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety , CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China , Beijing , China.

The first nano-platform commercialized as a drug delivery system was a liposomal formulation. The application of liposome technology resolved the issues of paclitaxel (PTX) insolubility and eliminated the use of solvents causing toxic side-effects, which enabled to apply higher drug doses leading to an enhanced drug efficacy. The growth-inhibitory activity of liposome-encapsulated PTX was retained in vitro against a variety of tumor cell. To investigate the drug efficacy in the system biological level, quantitative proteomic analysis was employed to study the molecular mechanism of the anti-tumor effect of Lipusu (lip) compared with PTX on lung cancer cell A549. The functions of the differential expressed proteins were correlated to the negative effect to cell proliferation due to regulation of hippo pathway and prolonged cell cycle, as well as inhibitory cell exocytosis, which would cause the aggregation of free PTX. This investigation focused on the direct biological effect of lip to cancer cells. It was different from pharmaceutical issues about drug exposure, delivery and distribution which were widely investigated in other traditional studies. It was the first study about the drug effect of lip from the global molecular biological aspect.
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http://dx.doi.org/10.1080/21691401.2018.1489822DOI Listing
June 2019

Unravelling the Self-Assembly of Diketopyrrolopyrrole-Based Photovoltaic Molecules.

Langmuir 2018 10 28;34(40):11952-11959. Epub 2018 Sep 28.

CAS Key Laboratory of Standardization and Measurement for Nanotechnology , CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology (NCNST) , Beijing 100190 , P. R. China.

The nanostructure of bulk heterojunction in an organic solar cell dominating the electron transport process plays an important role in improving the device efficiency. However, there is still a great need for further understanding the local nanostructures from the viewpoint of molecular design because of the complex alignment in the solid film. In this work, four kinds of photovoltaic materials containing a diketopyrrolopyrrole (DPP) unit combined with other different building blocks were selected and their self-assembled structures on a solid surface were studied by scanning tunneling microscopy technique in combination with theory calculations. The results reveal these DPP-based photovoltaic molecules self-assembled into different nanostructures, which strongly depend on the chemical structure, in particular the backbones and alkyl side chains. The planarities of backbones are affected both by molecule-substrate interaction and steric hindrance induced by the substituted thiophene or benzo[ b]thiophene units on DPP and porphyrin building blocks. The substituted branched alkyl side chains are out of the plane, which are influenced by the alignments of molecular backbones. In addition, the solution concentration also shows a large effect on the self-assembled nanostructures. This systematic research on the self-assembled structures of DPP-based semiconductors on a surface would provide guidance for designing materials and controlling the morphology of a donor/acceptor heterojunction system.
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http://dx.doi.org/10.1021/acs.langmuir.8b01798DOI Listing
October 2018

Conic shapes have higher sensitivity than cylindrical ones in nanopore DNA sequencing.

Sci Rep 2018 06 14;8(1):9097. Epub 2018 Jun 14.

CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, beijing, 100190, China.

Nanopores have emerged as helpful research tools for single molecule detection. Through continuum modeling, we investigated the effects of membrane thickness, nanopore size, and pore shape on current signal characteristics of DNA. The simulation results showed that, when reducing the pore diameter, the amplitudes of current signals of DNA increase. Moreover, we found that, compared to cylindrically shaped nanopores, conical-shaped nanopores produce greater signal amplitudes from biomolecules translocation. Finally, we demonstrated that continuum model simulations for the discrimination of DNA and RNA yield current characteristics approximately consistent with experimental measurements and that A-T and G-C base pairs can be distinguished using thin conical solid-state nanopores. Our study not only suggests that computational approaches in this work can be used to guide the designs of nanopore for single molecule detection, but it also provides several possible ways to improve the current amplitudes of nanopores for better resolution.
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http://dx.doi.org/10.1038/s41598-018-27517-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6002541PMC
June 2018

Autophagy protects auditory hair cells against neomycin-induced damage.

Autophagy 2017 2;13(11):1884-1904. Epub 2017 Oct 2.

a Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences , Southeast University , Nanjing , China.

Aminoglycosides are toxic to sensory hair cells (HCs). Macroautophagy/autophagy is an essential and highly conserved self-digestion pathway that plays important roles in the maintenance of cellular function and viability under stress. However, the role of autophagy in aminoglycoside-induced HC injury is unknown. Here, we first found that autophagy activity was significantly increased, including enhanced autophagosome-lysosome fusion, in both cochlear HCs and HEI-OC-1 cells after neomycin or gentamicin injury, suggesting that autophagy might be correlated with aminoglycoside-induced cell death. We then used rapamycin, an autophagy activator, to increase the autophagy activity and found that the ROS levels, apoptosis, and cell death were significantly decreased after neomycin or gentamicin injury. In contrast, treatment with the autophagy inhibitor 3-methyladenine (3-MA) or knockdown of autophagy-related (ATG) proteins resulted in reduced autophagy activity and significantly increased ROS levels, apoptosis, and cell death after neomycin or gentamicin injury. Finally, after neomycin injury, the antioxidant N-acetylcysteine could successfully prevent the increased apoptosis and HC loss induced by 3-MA treatment or ATG knockdown, suggesting that autophagy protects against neomycin-induced HC damage by inhibiting oxidative stress. We also found that the dysfunctional mitochondria were not eliminated by selective autophagy (mitophagy) in HEI-OC-1 cells after neomycin treatment, suggesting that autophagy might not directly target the damaged mitochondria for degradation. This study demonstrates that moderate ROS levels can promote autophagy to recycle damaged cellular constituents and maintain cellular homeostasis, while the induction of autophagy can inhibit apoptosis and protect the HCs by suppressing ROS accumulation after aminoglycoside injury.
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http://dx.doi.org/10.1080/15548627.2017.1359449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5788479PMC
June 2019

Bone morphogenetic protein 4 promotes the survival and preserves the structure of flow-sorted Bhlhb5+ cochlear spiral ganglion neurons in vitro.

Sci Rep 2017 06 14;7(1):3506. Epub 2017 Jun 14.

Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China.

SGNs are the primary auditory neurons, and damage or loss of SGNs leads to sensorineural hearing loss. BMP4 is a growth factor that belongs to the TGF-β superfamily and has been shown to play a key role during development, but little is known about its effect on postnatal cochlear SGNs in mice. In this study, we used the P3 Bhlhb5-cre/tdTomato transgenic mouse model and FACS to isolate a pure population of Bhlhb5+ SGNs. We found that BMP4 significantly promoted SGN survival after 7 days of culture. We observed fewer apoptotic cells and decreased expression of pro-apoptotic marker genes after BMP4 treatment. We also found that BMP4 promoted monopolar neurite outgrowth of isolated SGNs, and high concentrations of BMP4 preserved the number and the length of neurites in the explant culture of the modiolus harboring the SGNs. We showed that high concentration of BMP4 enhanced neurite growth as determined by the higher average number of filopodia and the larger area of the growth cone. Finally, we found that high concentrations of BMP4 significantly elevated the synapse density of SGNs in explant culture. Thus, our findings suggest that BMP4 has the potential to promote the survival and preserve the structure of SGNs.
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http://dx.doi.org/10.1038/s41598-017-03810-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5471210PMC
June 2017

Peptide probes derived from pertuzumab by molecular dynamics modeling for HER2 positive tumor imaging.

PLoS Comput Biol 2017 Apr 13;13(4):e1005441. Epub 2017 Apr 13.

CAS Key Laboratory for Biological Effects of Nanomaterials & Nanosafety, National Center for Nanoscience and Technology, Beijing, China.

A high level of HER2 expression in breast cancer correlates with a higher tumor growth rate, high metastatic potential, and a poor long-term patient survival rate. Pertuzumab, a human monoclonal antibody, can reduce the effect of HER2 overexpression by preventing HER2 dimerization. In this study, a combination protocol of molecular dynamics modeling and MM/GBSA binding free energy calculations was applied to design peptides that interact with HER2 based on the HER2/pertuzumab crystal structure. Based on a β hairpin in pertuzumab from Glu46 to Lys65-which plays a key role in interacting with HER2-mutations were carried out in silico to improve the binding free energy of the hairpin that interacts with the Phe256-Lys314 of the HER2 protein. Combined the use of one-bead-one-compound library screening, among all the mutations, a peptide (58F63Y) with the lowest binding free energy was confirmed experimentally to have the highest affinity, and it may be used as a new probe in diagnosing and treating HER2-positive breast cancer.
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http://dx.doi.org/10.1371/journal.pcbi.1005441DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390981PMC
April 2017

A Three-Dimensional Culture System with Matrigel Promotes Purified Spiral Ganglion Neuron Survival and Function In Vitro.

Mol Neurobiol 2018 03 10;55(3):2070-2084. Epub 2017 Mar 10.

Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.

In vitro culture of spiral ganglion neurons (SGNs) is a useful approach to investigate numerous aspects of neuronal behavior and to identify potential therapeutic targets for SGN protection and regeneration. However, the isolation of SGNs and the long-term maintenance of their structure and function in vitro remain challenging. In this study, we isolated SGNs from Bhlhb5-cre and Rosa26-tdTomato mice with fluorescence-activated cell sorting and determined the cell purity. We then encapsulated the pure SGNs in matrigel and cultured the SGNs in vitro. We found that the three-dimensional (3D)-matrigel culture environment significantly suppressed apoptosis and improved SGN survival in vitro, which enabled the long-term culture of SGNs for up to 6 months. The 3D-matrigel system also significantly promoted neurite outgrowth of the SGNs, increased the cells' polarity, promoted the area of growth cones, and significantly increased the synapse density of the SGNs. More importantly, the 3D-matrigel system helped to maintain and promote the electrophysiological properties of the SGNs. In conclusion, the 3D-matrigel culture system promoted the survival of purified SGNs in vitro and maintained their morphological structure and function and thus could be a useful tool for studying the physiology and pathophysiology of purified SGNs in long-term culture.
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http://dx.doi.org/10.1007/s12035-017-0471-0DOI Listing
March 2018
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