Publications by authors named "Cuicui Liu"

109 Publications

Trigeminal nerve electrical stimulation: An effective arousal treatment for loss of consciousness.

Brain Res Bull 2021 Apr 13;169:81-93. Epub 2021 Jan 13.

Department of Rehabilitation, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510030, China. Electronic address:

Background: To determine if trigeminal nerve electrical stimulation (TNS) would be an effective arousal treatment for loss of consciousness (LOC), we applied neuroscientific methods to investigate the role of potential brain circuit and neuropeptide pathway in regulating level of consciousness.

Methods: Consciousness behavioral analysis, Electroencephalogram (EEG) recording, Chemogenetics, Microarray analysis, Milliplex MAP rat peptide assay, Chromatin immune-precipitation (ChIP), Dual-luciferase reporter experiment, Western blot, PCR and Fluorescence in situ hybridization (FISH).

Results: TNS can markedly activate the neuronal activities of the lateral hypothalamus (LH) and the spinal trigeminal nucleus (Sp5), as well as improve rat consciousness level and EEG activities. Then we proved that LH activation and upregulated neuropeptide hypocretin are beneficial for promotion of consciousness recovery. We then applied gene microarray experiment and found hypocretin might be mediated by a well-known transcription factor Early growth response gene 1 (EGR1), and the results were confirmed by ChIP and Dual-luciferase reporter experiment.

Conclusion: This study illustrates that TNS is an effective arousal strategy Treatment for LOC state via the activation of Sp5 and LH neurons and upregulation of hypocretin expression.
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http://dx.doi.org/10.1016/j.brainresbull.2021.01.008DOI Listing
April 2021

Follow-up of a Rickettsia felis encephalitis: Some new insights into clinical and imaging features.

Int J Infect Dis 2021 Mar 11;104:300-302. Epub 2021 Jan 11.

Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong, China. Electronic address:

Rickettsia felis (R. felis) infection is a cause of unspecified encephalitis. However, the incidence has been underestimated due to the intracellular features of the pathogen and insufficient understanding of its clinical picture. This study reported a case of R. felis infection in a 26-year-old female who only manifested with certain neurological symptoms. With a lack of specific systemic inflammatory symptoms, the diagnosis was initially misdiagnosed as a brain glioma. However, a brain tissue biopsy showed prominent perivascular inflammatory infiltrations, which indicated inflammatory disease. Spinal fluid metagenomic next-generation sequencing (mNGS) was taken after ruling out other common infectious and autoimmune diseases. The results suggested R. felis infection, which was also supported by Weil-Felix reaction in the serum. After the diagnosis was corrected as R. felis encephalitis, the patient was successfully treated with doxycycline and had a good prognosis at the 1-year follow-up.
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http://dx.doi.org/10.1016/j.ijid.2020.12.090DOI Listing
March 2021

Carboxyl-functionalized hollow polymer microspheres for detection of trace metal elements in complex food matrixes by ICP-MS assisted with solid-phase extraction.

Ecotoxicol Environ Saf 2021 Jan 8;208:111729. Epub 2020 Dec 8.

State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China; Research Center of Food Science and Human Health, School of Medicine, Nankai University, Tianjin 300071, China. Electronic address:

In this work, carboxyl-functionalized hollow polymer microspheres (CHPMs) was successfully fabricated using poly (styrene-itaconic anhydride) particles as the core template and itaconic anhydride and trans-anethole cross-linked with divinylbenzene as the shell. The desirable microspheres and hollow structure of CHPMs were demonstrated by scanning and transmission electron microscopies, respectively. The characterized CHPMs as an adsorbent was packed into a solid phase extraction column to simultaneously detect the V(V), Cr(III), Cu(II), Cd(II), and Pb(II) in digested food samples by inductively coupled plasma-mass spectrometry (ICP-MS). A series of experimental parameters of solid-phase extraction (SPE) were investigated through vast experiments to improve sensitivity of the proposed method in metal ions detection. The detection limits of the method reached 0.8-3.2 ng L for the target elements, and the relative standard deviations (RSDs) ranging from 1.2% to 3.5% were obtained from eleven parallel experiments using a 1.0 μg L sample solution. The stability allowed the material to withstand more than 15 cycling while the recoveries remained above 88%. In food samples, the detection limits were at 0.20-0.80 μg kg, and satisfactory recoveries of 85-104% were obtained in spike tests of laver, fish as well as chicken.
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http://dx.doi.org/10.1016/j.ecoenv.2020.111729DOI Listing
January 2021

Understanding the role of tissue-specific decellularized spinal cord matrix hydrogel for neural stem/progenitor cell microenvironment reconstruction and spinal cord injury.

Biomaterials 2021 Jan 10;268:120596. Epub 2020 Dec 10.

PCFM Lab, Guangdong HPPC Lab, School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China; Guangdong Functional Biomaterials Engineering Technology Research Center, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, China. Electronic address:

The repair of spinal cord injury (SCI) highly relies on microenvironment remodeling and facilitating the recruitment and neuronal differentiation of endogenous stem/progenitor cells. Decellularized tissue matrices (DTMs) have shown their unique and beneficial characteristics in promoting neural tissue regeneration, especially those derived from the nervous system. Herein, we present a comparative analysis of a DTM hydrogel derived from spinal cord (DSCM-gel) and a decellularized matrix hydrogel derived from peripheral nerves (DNM-gel). The tissue-specificity of DSCM-gel was evaluated both in vitro, using neural stem/progenitor cell (NSPC) culture, and in vivo, using various materials and biological analyses, including transcriptome and proteomics. It was found that DSCM-gel retained an extracellular matrix-like nanofibrous structure but exhibited higher porosity than DNM-gel, which potentiated NSPCs viability, proliferation, and migration in the early stage of 3D culturing, followed by facilitation of the NSPCs differentiation into neurons. Transcriptome analysis indicated that DSCM-gel regulates NSPCs behavior by modulating integrin α2, α9, and β1 expression profiles along with AKT/ERK related signaling pathways. Proteomics analyses suggest that DSCM specific extracellular matrix proteins, such as the tenascin family (TNC) and some soluble growth factor (FGF2) may contribute to these regulations. Furthermore, in vivo assessments confirmed that DSCM-gel provides a suitable microenvironment for endogenous stem/progenitor cell recruitment and axonal regeneration for bridging the lesion site after a completely transected SCI. Thus, this systematic study provides key insights useful for the development of the tissue-specific DTM biomaterials for translational microenvironment replacement therapies and tissue repair.
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http://dx.doi.org/10.1016/j.biomaterials.2020.120596DOI Listing
January 2021

Decoding Human Megakaryocyte Development.

Cell Stem Cell 2021 Mar 18;28(3):535-549.e8. Epub 2020 Dec 18.

State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China; CAMS Center for Stem Cell Medicine, PUMC Department of Stem Cell and Regenerative Medicine, Tianjin 300020, China. Electronic address:

Despite our growing understanding of embryonic immune development, rare early megakaryocytes (MKs) remain relatively understudied. Here we used single-cell RNA sequencing of human MKs from embryonic yolk sac (YS) and fetal liver (FL) to characterize the transcriptome, cellular heterogeneity, and developmental trajectories of early megakaryopoiesis. In the YS and FL, we found heterogeneous MK subpopulations with distinct developmental routes and patterns of gene expression that could reflect early functional specialization. Intriguingly, we identified a subpopulation of CD42bCD14 MKs in vivo that exhibit high expression of genes associated with immune responses and can also be derived from human embryonic stem cells (hESCs) in vitro. Furthermore, we identified THBS1 as an early marker for MK-biased embryonic endothelial cells. Overall, we provide important insights and invaluable resources for dissection of the molecular and cellular programs underlying early human megakaryopoiesis.
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http://dx.doi.org/10.1016/j.stem.2020.11.006DOI Listing
March 2021

Platelet-rich plasma for the treatment of adolescent late-stage femoral head necrosis: a case report.

Regen Med 2020 09 26;15(9):2067-2073. Epub 2020 Nov 26.

Department of Rehabilitation Medicine, Sun Yat-sen Memorial Hospital, No.107 Yanjiang West Road, Guangzhou 510120, China.

Osteonecrosis of femoral head (ONFH) is a disabling and intractable disease. Previous studies reported the increasing failure rates of total hip arthroplasty in younger patients, thus there should be special considerations for the adolescents. In this paper, we present a case of an adolescent female with late-stage glucocorticoid-induced ONFH (according to the Association Research Circulation Osseous classification system, Association Research Circulation Osseous IV). The patient received five consecutive ultrasound-guided intra-articular injections of platelet-rich plasma, and the therapeutic effects were assessed by visual analog scale, joint range of motion, Western Ontario and McMaster Universities Osteoarthritis Index, Harris Hip Score and magnetic resonance imaging. At 9-month follow-up, clinical and radiological reassessments demonstrated favorable outcomes. This case highlights the therapeutic potential of platelet-rich plasma injections for the late-stage ONFH, especially for adolescent patients.
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http://dx.doi.org/10.2217/rme-2020-0057DOI Listing
September 2020

Primary central nervous system lymphomatoid granulomatosis: a case report.

Neurol Sci 2021 04 20;42(4):1587-1590. Epub 2020 Oct 20.

Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, No. 324 JingWu Road, Jinan, 250021, Shandong, People's Republic of China.

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http://dx.doi.org/10.1007/s10072-020-04833-4DOI Listing
April 2021

Primary Central Nervous System Lymphomatoid Granulomatosis: Systemic Review.

Front Neurol 2020 11;11:901. Epub 2020 Sep 11.

Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.

Lymphomatoid granulomatosis (LYG) is an infrequent lymphoproliferative disease that typically involves the lungs, but may also affect the central nervous system (CNS). Isolated CNS involvement is very rare, and its clinicopathological features have not been fully elucidated. Here, we systematically reviewed the English literature through PubMed to collect all relevant case reports and small case series with pathologically confirmed primary CNS-LYG. A total of 29 relevant articles with 40 cases were included in this systemic review. In cases where T cells and B cells were compared, T cells were predominant in 19 (79.2%), and B cells were predominant in 5 (20.8%). The overall infection rate of EBV was 48.1% (13/27), among which the infection rate was 40.9% (9/22) in immunocompetent patients and 80% (4/5) in immunodeficient (HIV-infected) patients. Among the patients who underwent pathological grading, 35.7% (5/14) were at grade I, 42.9% (6/14) were at grade II, and 21.4% were at grade III. In conclusion, primary CNS-LYG is closely related to EBV infection and some cases may be predominantly T-cell phenotype. Surgical resection may be effective for mass-like lesions, although there is still a lack of standard therapeutic regimen. Accurate grading of lesions is essential for treatment selection and prognosis evaluation.
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http://dx.doi.org/10.3389/fneur.2020.00901DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7516720PMC
September 2020

Open-tubular radially cyclical electric field-flow fractionation (OTR-CyElFFF): an online concentric distribution strategy for simultaneous separation of microparticles.

Lab Chip 2020 09;20(19):3535-3543

Department of Chemistry, Yanbian University, Park Road 977, Yanji City, Jilin Province 133002, PR China.

An open-tubular radially cyclical electric field-flow fractionation technique which achieves the online separation of microparticles in a functional annular channel is proposed in this study. The system was set up by using a stainless steel tube and a platinum wire modified with ionic liquid/mesoporous silica materials as the external and internal electrodes. The feasibility for online separation of various particles was experimentally demonstrated. Particles in the channel were affected by a radial electric field and field-flow fractionation (FFF). On the cross section, different particles showed distinctive migration distances depending on their own properties and the different magnitudes of forces being exerted. The same kind of particles form an annular distribution within the same annulus while different particles form annular distributions at varied concentric annuli through electrophoresis. Under a laminar flow of FFF, different sizes of particles formed a conical arrangement within the annular separation channel. With the joint influence of electric field and flow field, different trajectories were obtained and the particles were eventually separated. Voltage, frequency and duty cycle value are the main parameters affecting the separation of particles. By adjusting these parameters, particles migrate in a zigzag trajectory on one side of the electrodes (mode I) and reach both sides of the electrodes (mode II). Six polystyrene particles were completely separated with high resolution within several minutes. Our system offers numerous advantages of label-free, high-resolution and online separation without tedious operations, and it is a promising tool for the effective separation of various micro-objects.
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http://dx.doi.org/10.1039/d0lc00620cDOI Listing
September 2020

COR27 and COR28 Are Novel Regulators of the COP1-HY5 Regulatory Hub and Photomorphogenesis in Arabidopsis.

Plant Cell 2020 10 7;32(10):3139-3154. Epub 2020 Aug 7.

National Key Laboratory of Plant Molecular Genetics, Chinese Academy of Sciences Center for Excellence in Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, the Chinese Academy of Sciences, Shanghai 200032, People's Republic of China

Plants have evolved sensitive signaling systems to fine-tune photomorphogenesis in response to changing light environments. Light and low temperatures are known to regulate the expression of the () genes and , which influence the circadian clock, freezing tolerance, and flowering time. Blue light stabilizes the COR27 and COR28 proteins, but the underlying mechanism is unknown. We therefore performed a yeast two-hybrid screen using COR27- and COR28 as bait and identified the E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) as an interactor. COR27 and COR28 physically interact with COP1, which is in turn responsible for their degradation in the dark. Furthermore, COR27 and COR28 promote hypocotyl elongation and act as negative regulators of photomorphogenesis in Arabidopsis (). Genome-wide gene expression analysis showed that HY5, COR27, and COR28 co-regulate many common genes. COR27 interacts directly with HY5 and associates with the promoters of the HY5 target genes and , then regulates their transcription together with HY5. Our results demonstrate that COR27 and COR28 act as key regulators in the COP1-HY5 regulatory hub, by regulating the transcription of HY5 target genes together with HY5 to ensure proper skotomorphogenic growth in the dark and photomorphogenic development in the light.
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http://dx.doi.org/10.1105/tpc.20.00195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7534460PMC
October 2020

An unusual case of recurrent episodes of muscle weakness: Co-occurrence of Andersen-Tawil syndrome and glycogen storage disease type IXd.

Neuromuscul Disord 2020 07 12;30(7):562-565. Epub 2020 Jun 12.

Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan City, China.

A 25-year-old male patient presented with periodic paralysis that increased in severity and frequency with age, accompanied with muscle pain and significantly elevated creatine kinase (CK) levels. Initial clinical and genetic examination confirmed Andersen-Tawil syndrome. Although his father carried the same genetic mutation (p.G300A), he experienced minor and infrequent attacks of paralysis. A change in the patient's symptoms, such as accompanying pain, contracture, and significant CK elevation, lead to a reconsideration of the diagnosis. A muscle biopsy of the biceps brachii in the patient revealed glycogen storage, but no tubular aggregates. Analysis of the phosphorylase kinase regulatory subunit alpha 1 (PHKA1) gene revealed a pathogenic mutation (p.C1082X), indicating glycogen storage disease type Ⅸd. The case demonstrates that co-occurrence of glycogen storage disease type Ⅸd may prolong attacks of muscle weakness, and cause serious muscle pain in patients with Andersen-Tawil syndrome.
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http://dx.doi.org/10.1016/j.nmd.2020.06.006DOI Listing
July 2020

Functional dissection of HGGT and HPT in barley vitamin E biosynthesis via CRISPR/Cas9-enabled genome editing.

Ann Bot 2020 10;126(5):929-942

Institute of Genetics and Regenerative Biology, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, College of Life Sciences, Zhejiang University, Hangzhou, China.

Background And Aims: Vitamin E (tocochromanol) is a lipid-soluble antioxidant and an essential nutrient for human health. Among cereal crops, barley (Hordeum vulgare) contains a high level of vitamin E, which includes both tocopherols and tocotrienols. Although the vitamin E biosynthetic pathway has been characterized in dicots, such as Arabidopsis, which only accumulate tocopherols, knowledge regarding vitamin E biosynthesis in monocots is limited because of the lack of functional mutants. This study aimed to obtain gene knockout mutants to elucidate the genetic control of vitamin E composition in barley.

Methods: Targeted knockout mutations of HvHPT and HvHGGT in barley were created with CRISPR/Cas9-enabled genome editing. High-performance liquid chromatography (HPLC) was performed to analyse the content of tocochromanol isomers in transgene-free homozygous Hvhpt and Hvhggt mutants.

Key Results: Mutagenesis efficiency among T0 regenerated plantlets was 50-65 % as a result of two simultaneously expressed guide RNAs targeting each gene; most of the mutations were stably inherited by the next generation. The transgene-free homozygous mutants of Hvhpt and Hvhggt exhibited decreased grain size and weight, and the HvHGGT mutation led to a shrunken phenotype and significantly lower total starch content in grains. HPLC analysis revealed that targeted mutation of HvHPT significantly reduced the content of both tocopherols and tocotrienols, whereas mutations in HvHGGT completely blocked tocotrienol biosynthesis in barley grains. Transient overexpression of an HvHPT homologue in tobacco leaves significantly increased the production of γ- and δ-tocopherols, which may partly explain why targeted mutation of HvHPT in barley grains did not eliminate tocopherol production.

Conclusions: Our results functionally validated that HvHGGT is the only committed gene for the production of tocotrienols, whereas HvHPT is partly responsible for tocopherol biosynthesis in barley.
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http://dx.doi.org/10.1093/aob/mcaa115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7539355PMC
October 2020

SETDB2 promoted breast cancer stem cell maintenance by interaction with and stabilization of ΔNp63α protein.

Int J Biol Sci 2020 18;16(12):2180-2191. Epub 2020 May 18.

Department of Laboratory Medicine & Central Laboratory, Southern Medical University Affiliated Fengxian Hospital, Shanghai 201499, China.

The histone H3K9 methyltransferase SETDB2 is involved in cell cycle dysregulation in acute leukemia and has oncogenic roles in gastric cancer. In our study, we found that SETDB2 plays essential roles in breast cancer stem cell maintenance. Depleted SETDB2 significantly decreased the breast cancer stem cell population and mammosphere formation and also inhibited breast tumor initiation and growth . Restoring SETDB2 expression rescued the defect in breast cancer stem cell maintenance. A mechanistic analysis showed that SETDB2 upregulated the transcription of the ΔNp63α downstream Hedgehog pathway gene. SETDB2 also interacted with and methylated ΔNp63α, and stabilized ΔNp63α protein. Restoring ΔNp63α expression rescued the breast cancer stem cell maintenance defect which mediated by SETDB2 knockdown. In conclusion, our study reveals a novel function of SETDB2 in cancer stem cell maintenance in breast cancer.
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http://dx.doi.org/10.7150/ijbs.43611DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7294945PMC
May 2020

Proteomic profiling analysis of postmenopausal osteoporosis and osteopenia identifies potential proteins associated with low bone mineral density.

PeerJ 2020 14;8:e9009. Epub 2020 Apr 14.

Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, China.

Postmenopausal osteoporosis (PMOP) is a major global public health concern and older women are more susceptible to experiencing fragility fractures. Our study investigated the associations between circulating proteins with bone mineral density (BMD) in postmenopausal women with or without low BMD (osteoporosis and osteopenia) using a tandem mass tag (TMT) labeling proteomic experiment and parallel reaction monitoring testing. Across all plasma samples, we quantitatively measured 1,092 proteins, and the OP and normal control (NC) samples were differentiated by principal component analysis and a partial least squares-discrimination analysis model based on the protein profiling data. The differentially abundant proteins between the low BMD and NC samples mostly exhibited binding, molecular function regulator, transporter and molecular transducer activity, and were involved in metabolic and cellular processes, stimulus response, biological regulation, immune system processes and so forth. TMT analysis and RRM validation indicated that the expression of protein Lysozyme C (P61626) was negatively related to BMD, while the expression of proteins Glucosidase (A0A024R592) and Protein disulfideisomerase A5 (Q14554) was positively related to BMD values. Collectively, our results suggest that postmenopausal women with low BMD have a different proteomic profile or signature. Protein alterations may play an important role in the pathogenesis of PMOP, and they may act as novel biomarkers and targets of therapeutic agents for this disease.
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http://dx.doi.org/10.7717/peerj.9009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7164430PMC
April 2020

YAP1, targeted by miR-375, enhanced the pro-angiogenesis of airway smooth muscle cells in asthma via STAT3 activation.

Cell Cycle 2020 06 19;19(11):1275-1284. Epub 2020 Apr 19.

Department of Respiratory and Asthma, Xi'an Children's Hospital , Xi'an, Shanxi, China.

YAP1 was previously reported to regulate the development of multiple tumors, angiogenesis included. Angiogenesis was a specific process of remodeling in asthma. In a recent study, YAP1 was correlated with the progression of asthma. However, the role of YAP1 in airway smooth muscle cell and the asthmatic airway angiogenesis was unclear. In the present study, we used cytokine-stimulated airway smooth muscle cells as asthma cell model in vitro. The results showed a significant up-regulation of YAP1 in asthmatic airway smooth muscle tissue and cytokine-stimulated asthmatic cell model by Western blot. The experimental results of YAP1 loss-of-function combined with STAT3 inhibitor (WP1066) showed that YAP1 knockdown inhibited the expression of VEGF by deactivating STAT3 in cytokine-stimulated ASM cells, which hindered the pro-angiogenesis ability of ASM cells. Besides, by combining prediction and binding site mutation along with luciferase reporter gene experiments, we confirmed direct binding between miR-375 and YAP1. Based on that, the decreased expression level of miR-375 was found to be correlated with the pathogenesis of asthma. Finally, miR-375 was verified to participate in the YAP1-regulated pro-angiogenesis ability of ASM cells. To sum up, we provided the evidence that YAP1 directly binds to miR-375 and takes part in the regulation of the pro-angiogenic ability of ASM cells by activating STAT3 and VEGF signaling.
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http://dx.doi.org/10.1080/15384101.2020.1746874DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7469496PMC
June 2020

Effects of CDK6 regulated by miR-298 on proliferation and apoptosis of thyroid cancer cells.

Oncol Lett 2020 Apr 14;19(4):2909-2915. Epub 2020 Feb 14.

Department of Pharmacology, Cangzhou Medical College, Cangzhou, Hebei 061000, P.R. China.

Effects of CDK6 regulated by miR-298 on proliferation and apoptosis of thyroid cancer cells were explored. Seventy-five cases of thyroid carcinoma and adjacent tissues were collected. The expression levels of miR-298 and CDK6 mRNA in tissues and cells were detected by RT-PCR. In addition, thyroid cancer cells and human normal thyroid cells Nthy-ori3-1 were purchased, with the former transfected with miR-298-mimics, miR-298-inhibitor, miR-NC, si-CDK6, si-NC, Sh-CDK6, Sh-NC to build cell models. Then the expression levels of miR-298 and CDK6 in thyroid cancer tissues and cells were detected by qRT-PCR, and the expression of CDK6, Bax, Bcl-2 and caspase-3 by WB. CCK-8 and flow cytometry were employed to detect cell proliferation and apoptosis, and dual luciferase report was adopted to determine the relationship between miR-298 and CDK6. miR-298 was underexpressed in thyroid cancer, and CDK6 was highly expressed in thyroid cancer. Cell experiments revealed that overexpression of miR-298 or inhibition of CDK6 expression could suppress cell proliferation, promote apoptosis, and significantly increase the expression levels of Bax and caspase-3 proteins, decrease Bcl-2 protein expression, which was contrary to the biological phenotype of cells after inhibition of miR-298 or further overexpression of CDK6. Dual luciferase report confirmed that miR-298 was a targeting site of CDK6. miR-298 can inhibit the proliferation of thyroid cells and promote apoptosis of thyroid cancer cells by regulating the expression of CDK6, which is expected to be a potential target for clinical application.
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http://dx.doi.org/10.3892/ol.2020.11398DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7068225PMC
April 2020

Comparative study of β-glucan-degrading enzymes from Coprinopsis cinerea for their capacities to induce stipe cell wall extension.

Int J Biol Macromol 2020 Jun 26;152:516-524. Epub 2020 Feb 26.

Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, 1 Wenyuan Rd, Xianlin University Park, Nanjing 210046, PR China. Electronic address:

We previously reported endo-β-1,3-glucanase ENG in combination with β-glucosidase BGL2 at low concentration induced stipe cell wall extension. This study further explored ENG could be replaced by endo-β-1,3(4)-glucanase ENG16A in combination with BGL2 to induce stipe cell wall extension; similarly, BGL2 could be replaced by β-glucosidase BGL1 to cooperate with ENG to induce stipe cell wall extension. However, ENG could not be replaced by exo-β-1,3-glucanase EXG in combination with BGL2 to induce stipe cell wall extension, although EXG alone released higher level of soluble sugars from the stipe cell walls during the reconstituted wall extension than that released from the stipe cell walls by a combination of ENG16A or ENG and BGL2 or BGL1, which was different from chitinase-mediated stipe cell wall extension. These results indicate endo-β-1,3-glucanases loosen the stipe cell wall, whereas exo-β-1,3-glucanases and β-glucosidases play a synergistic role to maintain a low and efficient concentration of endo-β-1,3-glucanases for stipe cell wall extension. Furthermore, ENG was expressed at a very high level in the matured pilei, in contrast, ENG16A was expressed at a very high level in the elongating apical stipe. Therefore, ENG16A might be involved in stipe elongation growth, while ENG might participate in autolysis of pilei.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.02.299DOI Listing
June 2020

Size-based bioavailability of land-based DON and its impact on eutrophication of Jiaozhou bay.

Mar Pollut Bull 2020 Mar 17;152:110898. Epub 2020 Jan 17.

Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qing Dao 266100, China.

With the increase in human activities, dissolved organic nitrogen (DON) has been the major nitrogen pool, which might impact on eutrophication of coastal water. We studied the bioavailability of different molecular size DON from the major sources of agricultural, domestic, industrial, and urban non-point source, respectively, in Jiaozhou bay, China. By clarifying the relationship between the source and molecular size, the bioavailability of terrestrial DON can be further understood based on the aspects of bioavailability proportion (BDON%) and kinetics with the help of ultraviolet radiation. The bioavailability proportion of high molecular size DON (HDON; >1000 Da) was higher than that of low molecular size DON (LDON; <1000 Da), with values of 58.0% to 35.1% for the HDON and values of 47.2% to 29.5% for the LDON, respectively. There were significant differences in the degradation rate constants (p < 0.05), which varied from 0.30 to 0.67 d for HDON and from 0.13 to 0.75 d for LDON. The SUVA values were significantly and negatively correlated with the bioavailabilities of DON, which can reflect to some extent the structure and molecular size. In order to study the influences of the different terrestrial DON inputs on the eutrophication of Jiaozhou bay, a modified 3D coupled biogeochemical model was used based on the survey data in August 2012. Two scenarios of DON loads from Haibo river and Dagu river were modeled. The impact on eutrophication of Jiaozhou bay is higher for the agricultural source of DON from Dagu river than for the domestic source from Haibo river.
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http://dx.doi.org/10.1016/j.marpolbul.2020.110898DOI Listing
March 2020

Investigating Polymer Transformation during the Encapsulation of Metal Nanoparticles by Polystyrene--poly(acrylic acid) in Colloids.

ACS Appl Mater Interfaces 2020 Jan 7;12(3):3969-3975. Epub 2020 Jan 7.

Department of Chemistry and Biological Chemistry , Nanyang Technological University , 50 Nanyang Avenue , Singapore 639798 , Singapore.

The colloidal self-assembly method holds great potential for large-scale synthesis at low expense of energy as compared to methods that assemble molecules by manipulating building blocks one after another. The development of the colloidal method, however, requires careful and intelligent design of the single building blocks as numerous degrees of freedom like isotropic nanoparticles (NPs) generally form highly repetitive, lattice-like structures or random aggregates upon self-assembly because of their identical surfaces throughout. Specifically, it is an interesting direction that if one can precisely control the localization of surface functionalities (i.e., ligands or polymer shells) on the NPs, a plethora of self-assembled structures (e.g., chains, sheets, rings, twisted, and even staircase structures) would be possible. Despite numerous simulations and modeling for this type of NPs, just a handful literature studies reported the controlling synthesis of metal-polymer patchy NPs through polymer shell shrinking/transformation in colloids. However, there are no detailed control experiments showing the mechanism of this polymer shell shrinking or transformation phenomenon. With the absence of a fundamental understanding of the driving forces and interactions between metal NP surface ligands and the hydrophobic polymer shell domain, simple and efficient design and synthesis of unique metal-polymer hybrid nanostructures are still obscure. Here, we report a detailed mechanistic study on the polymer shell transformation by using different types of surface ligands in encapsulation of metal NPs by polymer shells. The polymer shell transformation dynamic is studied after postheating treatment. The polymer shell transformation/shrinking on the metal NP surface depends on its surface ligand size being applied in the encapsulation step (polymer-ligand hydrophobic interaction effect). Longer-chain ligands provide stronger interactions between NPs and the hydrophobic domain of the polymer shell, which inhibits the polymer shell transformation. In contrast, short-chain ligands lead to weaker interactions, which assist in the polymer shell transformation. By understanding the underlying mechanisms, many new types of NPs, such as metal-polymer core-shell NPs, metal-polymer Janus NPs, silica-metal-polymer hybrid NPs, and silica-metal-polymer flower-like NPs have been synthesized for the first time. A new bottom-up platform for the synthesis of anisotropic NPs with the ability to control the patches in a precise manner has been created, which will benefit both nanotechnology (such as self-assembly in the nanoscale) and applications such as selective detection of the underlying ligands on the metal surface by using a surface-enhanced Raman spectrum study.
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http://dx.doi.org/10.1021/acsami.9b19264DOI Listing
January 2020

Myricitrin exhibits anti-atherosclerotic and anti-hyperlipidemic effects in diet-induced hypercholesterolemic rats.

AMB Express 2019 Dec 21;9(1):204. Epub 2019 Dec 21.

Department of Cardiovascular Surgery, Affiliated Hospital of Qingdao University, Qingdao, 266000, China.

The present study investigated the anti-atherosclerotic potential of myricitrin in hypercholesterolemic rats. Rats were divided into the following groups: sham (standard food), control [1% high-cholesterol diet (HCD)], 1 μM myricitrin + 1% HCD, 10 μM myricitrin + 1% HCD, 100 μM myricitrin + 1% HCD, and the positive control (10 mg/kg body weight atorvastatin). The dose was given to rats via oral gavage for 45 consecutive days. Feeding of rats with 1% HCD caused substantial increases in the levels of LDL, cholesterol, and triglycerides (TG), while high-density lipoprotein (HDL) was reduced. However, rats supplemented with myricitrin had reduced levels of cholesterol, LDL, and TG to near-normal levels, whereas HDL was increased. Catalase, superoxide dismutase (SOD), glutathione peroxidase (Gpx), and reduced glutathione (GSH) levels were substantially reduced in the HCD-fed rats compared with sham rats. However, the rats supplemented with 100 μM myricitrin showed > 50% increases in these levels. Lipid peroxidation and reactive oxygen species (ROS) levels were reduced following myricitrin treatment. The aortic cell wall area was significantly increased by 14.5% in HCD-fed rats. However, rats supplemented with 1, 10, and 100 μM myricitrin showed significant reductions in the aortic cell wall area of 2.3%, 4%, and 27.5%, respectively. This is the first report of the anti-atherosclerotic and hypolipidemic effects of myricitrin in hypercholesterolemic rats. Myricitrin decreased the level of total serum cholesterol and the role of aortic atherosclerosis in hypercholesterolemic rats.
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http://dx.doi.org/10.1186/s13568-019-0924-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6925610PMC
December 2019

HMGB1 was negatively regulated by HSF1 and mediated the TLR4/MyD88/NF-κB signal pathway in asthma.

Life Sci 2020 Jan 9;241:117120. Epub 2019 Dec 9.

Department of Respiratory and Asthma, Xi'an Children's Hospital, Xi'an, Shaanxi, 710003, PR China. Electronic address:

Aims: The present study explored the function and regulatory mechanism of High mobility group box 1 (HMGB1) in asthma.

Main Methods: OVA (ovalbumin)-induced asthmatic mice model and LPS-treated cellular model were established in this study. Airway inflammation was measured through detecting the expression of IL-4, IL-5, IL-13 and Interferon-γ (IFN-γ) in serum and BALF (bronchoalveolar lavage fluid) by ELISA kits. Bioinformatics predictive analysis, ChIP assays, Luciferase reporter assay and Western blotting were used to explore the relation between HMGB1 and HSF1 (Heat shock factor 1).

Key Findings: HMGB1 expression was increased in OVA-induced asthmatic mice. Silencing HMGB1 attenuated the increasing of IgE, inflammatory factors (IL-4, IL-5 and IL-13), and airway hyperresponsiveness that induced by OVA. In addition, our study found that HSF1 directly bind with the HMGB1 promoter and negatively regulation of HMGB1. HSF-1 were upregulated in OVA-induced asthmatic mice, and knockdown of HSF1 aggravated the OVA-induced airway inflammation and airway hyperreactivity in mice may through promoting the expression of HMGB1 and the activation of the Toll-like receptor 4 (TLR4)/Myeloid differentiation primary response 88 (MyD88)/Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signal pathway.

Significance: The expression of HMGB1 could be negatively regulated by HSF1, and the TLR4/MyD88/NF-κB signal pathway was involved in HSF1/HMGB1-mediated regulation of asthma.
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http://dx.doi.org/10.1016/j.lfs.2019.117120DOI Listing
January 2020

β-Glucosidase BGL1 from Exhibits a Distinctive Hydrolysis and Transglycosylation Activity for Application in the Production of 3-O-β-d-Gentiobiosyl-d-laminarioligosaccharides.

J Agric Food Chem 2019 Sep 17;67(38):10744-10755. Epub 2019 Sep 17.

Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science , Nanjing Normal University , Nanjing 210023 , PR China.

We previously reported that β-glucosidase BGL1 at low concentration (15 μg mL) from exhibited hydrolytic activity only toward laminarioligosaccharides but not toward cellooligosaccharides and gentiobiose. This study shows that BGL1 at high concentration (200 μg mL) also hydrolyzed cellobiose and gentiobiose, which accounted for only 0.83 and 2.05% of its activity toward laminaribiose, respectively. Interestingly, BGL1 at low concentration (1.5 μg mL) showed transglycosylation but BGL1 at high concentration (200 μg mL) did not. BGL1 utilizes only laminarioligosaccharides but not glucose, gentiobiose, and cellobiose to synthesize the higher oligosaccharides. BGL1 transferred one glucosyl residue from substrate laminarioligosaccharide to another laminarioligosaccharide as an acceptor in a β(1 → 3) or β(1 → 6) fashion to produce higher laminarioligosaccharides or 3-O-β-d-gentiobiosyl-d-laminarioligosaccharides. The BGL1-digested laminaritriose exhibited approximately 90% enhancement in the anti-oxidant activity compared to that of untreated laminaritriose, implying a potential application of BGL1-based transglycosylation for the production of high value-added rare oligosaccharides.
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http://dx.doi.org/10.1021/acs.jafc.9b04488DOI Listing
September 2019

Glucanase-Induced Stipe Wall Extension Shows Distinct Differences from Chitinase-Induced Stipe Wall Extension of Coprinopsis cinerea.

Appl Environ Microbiol 2019 11 16;85(21). Epub 2019 Oct 16.

Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China

This study reports that a high concentration of the endo-β-1,3-glucanase ENG (200 μg ml) induced heat-inactivated stipe wall extension of , whereas a high concentration of the extracellular β-glucosidase BGL2 (1,000 μg ml) did not; however, in combination, low concentrations of ENG (25 μg ml) and BGL2 (260 μg ml) induced heat-inactivated stipe cell wall extension. In contrast to the previously reported chitinase-reconstituted stipe wall extension, β-1,3-glucanase-reconstituted heat-inactivated stipe cell wall extension initially exhibited a fast extension rate that quickly decreased to zero after approximately 60 min; the stipe cell wall extension induced by a high concentration of β-1,3-glucanase did not result in stipe breakage during measurement, and the inner surfaces of glucanase-reconstituted extended cell walls still remained as amorphous matrices that did not appear to have been damaged. These distinctive features of the β-1,3-glucanase-reconstituted wall extension may be because chitin chains are cross-linked not only to the nonreducing termini of the side chains and the backbones of β-1,6 branched β-1,3-glucans but also to other polysaccharides. Remarkably, a low concentration of either the β-1,3-glucanase ENG or of chitinase ChiE1 did not induce heat-inactivated stipe wall extension, but a combination of these two enzymes, each at a low concentration, showed stipe cell wall extension activity that exhibited a steady and continuous wall extension profile. Therefore, we concluded that the stipe cell wall extension is the result of the synergistic actions of glucanases and chitinases. We previously reported that the chitinase could induce stipe wall extension and was involved in stipe elongation growth of the mushroom In this study, we explored that β-1,3-glucanase also induced stipe cell wall extension. Interestingly, the extension profile and extended ultra-architecture of β-1,3-glucanase-reconstituted stipe wall were different from those of chitinase-reconstituted stipe wall. However, β-1,3-glucanase cooperated with chitinase to induce stipe cell wall extension. The significance of this synergy between glucanases and chitinases is that it enables a low concentration of active enzymes to induce wall extension, and the involvement of β-1,3-glucanases is necessary for the cell wall remodeling and the addition of new β-glucans during stipe elongation growth.
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http://dx.doi.org/10.1128/AEM.01345-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6803297PMC
November 2019

Effect of Core Stability Training Monitored by Rehabilitative Ultrasound Image and Surface Electromyogram in Local Core Muscles of Healthy People.

Pain Res Manag 2019 23;2019:9130959. Epub 2019 Jun 23.

Rehabilitation Medicine Department, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.

Background: The purpose of this study is to investigate the influence of transverses abdominis and lumbar multifidus thickness activation and electromyogram signal characteristics after core stability training monitored by rehabilitative ultrasound imaging and surface electromyogram.

Methods: 60 healthy volunteers were allocated randomly into two groups, one of which received monitoring training and the other participated identical training without monitoring. Ultrasound image and surface electromyogram signal were collected at 0, 4, and 8 weeks during training. The muscle thickness activation ratio value and integrated electromyogram value were then extracted. During the training, the monitoring group was monitored by real-time rehabilitative ultrasound imaging and surface electromyogram while the control group was not.

Results: There are no differences in performance of local core muscles between both groups before training ( > 0.05). Compared with the control group, the thickness contraction ratio value and integrated electromyogram value of core muscles in the monitoring group were higher after 8 weeks' training ( < 0.05).

Conclusion: Together, the core stability training monitored by rehabilitative ultrasound imaging and surface electromyogram can markedly activate and enhance local core muscles in healthy people, providing a potential strategy to treat low back pain more effectively.
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http://dx.doi.org/10.1155/2019/9130959DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6612403PMC
December 2019

A case of recurrent vomiting: extending the spectrum of neuronal intranuclear inclusion disease.

Neurol Sci 2019 12 2;40(12):2661-2664. Epub 2019 Jul 2.

Department of Neurology, Shandong Provincial Hospital affiliated to Shandong University, 324# Jingwu Road, Jinan, 250021, People's Republic of China.

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http://dx.doi.org/10.1007/s10072-019-03986-1DOI Listing
December 2019

Generation of functional dopaminergic neurons from human spermatogonial stem cells to rescue parkinsonian phenotypes.

Stem Cell Res Ther 2019 06 27;10(1):195. Epub 2019 Jun 27.

Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Xi'an, 710054, China.

Background: Recent progress in the induced generation of dopaminergic (DA) neurons from different types of stem cells or reprogrammed somatic cells holds tremendous potential for the treatment of Parkinson's disease (PD). However, the lack of a reliable source for cell replacement therapy remains a major limitation in the treatment of human neurological disorders. Additionally, the current protocols for in vitro differentiation or cell reprogramming to generate human DA neurons are laborious, time-consuming, and expensive, and efficient conversion of human spermatogonial stem cells (hSSCs) to functional DA neurons has not yet been achieved.

Methods: Primary hSSCs from testicular tissues of patients were exposed to an improved induction system, which consisted mainly of olfactory ensheathing cell conditioned culture medium (OECCM) and a set of defined cell-extrinsic factors and small molecules. Morphological changes were assessed, along with the expression of various DA neuron phenotypic markers (e.g., Tuj-1, TH, Nurr1, DAT) and several critical pro-DA neurogenesis effectors (e.g., EN-1, Pitx3, Foxa2, Lmx1a, Lmx1b, and OTX2). In addition, transcriptome analysis was used to further evaluate the genetic similarity between the artificially differentiated DA neurons and genuine ones. Concomitantly, the functional properties of converted DA neurons including synapse formation, dopamine release, electrophysiological activity, and neuron-specific Ca signaling images were determined. Finally, hSSCs in the early stage of induction were evaluated for survival, differentiation, migration, tumorigenicity in the mouse striatum, and improvement of functional deficits in MPTP-induced PD animals.

Results: The hSSC-derived neurons not only acquired neuronal morphological features but also expressed various phenotypic genes and protein characteristic of DA neurons and several effectors critical for pro-DA neurogenesis. Strikingly, as the period of induction was prolonged, expression of the critical molecules for DA neuron epigenetic status gradually increased while hSSC-specific markers sharply decreased. After 3 weeks of induction, the transdifferentiation efficiency reached 21%. In addition, hierarchical clustering analysis showed that the differentiated DA neurons closely resembled genuine ones. Furthermore, the hSSC-derived neurons gained sophisticated functional properties of wild-type DA neurons, and pro-induced hSSCs efficiently survived, migrated, and differentiated into DA neurons without tumorigenesis after transplantation into mouse striatum, leading to improvement of functional deficits in PD animals.

Conclusions: The results showed that, using the present improved straightforward approach, hSSCs could acquire DA neuron morphological features and functional properties and rescue parkinsonian phenotypes. Our strategy for the conversion of hSSCs into DA neurons is very efficient and thus may provide an alternative approach suitable for clinical cell therapy to treat neurodegenerative diseases including PD.
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http://dx.doi.org/10.1186/s13287-019-1294-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6598262PMC
June 2019

Histone demethylase KDM7A is required for stem cell maintenance and apoptosis inhibition in breast cancer.

J Cell Physiol 2020 02 24;235(2):932-943. Epub 2019 Jun 24.

Fengxian District Center Hospital Graduate Student Training Base, Jinzhou Medical University, Shanghai, 201499, China.

Histone demethylase KDM7A regulates neuronal differentiation and development in mammals. In this study, we found that KDM7A was also required for breast cancer stem cells (BCSCs) maintenance. Silencing KDM7A significantly reduced the BCSCs population and mamosphere formation in vitro, and inhibited breast tumor growth in vivo. Restoring KDM7A expression rescued the defect in stem cell maintenance. Our mechanism analysis suggested that KDM7A upregulated the stemness-associated factors KLF4 and c-MYC for BCSCs maintenance. In addition, KDM7A knockdown promoted apoptosis through decreasing BCL2 expression and BAD phosphorylation in breast cancer (BrCa). Furthermore, restoring KDM7A and BCL2 expression rescued apoptosis inhibition in breast cancer, suggesting that KDM7A inhibited apoptosis by upregulating the BCL2 level in breast cancer. In conclusion, KDM7A promotes cancer stem cell maintenance and apoptosis inhibition in breast cancer.
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http://dx.doi.org/10.1002/jcp.29008DOI Listing
February 2020

Sonic Hedgehog Effectively Improves Oct4-Mediated Reprogramming of Astrocytes into Neural Stem Cells.

Mol Ther 2019 08 16;27(8):1467-1482. Epub 2019 May 16.

Translational Medicine Center, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China; Department of Spine Surgery, Hong Hui Hospital, Xi'an Jiaotong University, Shaanxi 710054, China. Electronic address:

Irreversible neuron loss following spinal cord injury (SCI) usually results in persistent neurological dysfunction. The generation of autologous neural stem cells (NSCs) holds great potential for neural replenishment therapies and drug screening in SCI. Our recent studies demonstrated that mature astrocytes from the spinal cord can directly revert back to a pluripotent state under appropriate signals. However, in previous attempts, the reprogramming of astrocytes into induced NSCs (iNSCs) was unstable, inefficient, and frequently accompanied by generation of intermediate precursors. It remained unknown how to further increase the efficiency of astrocyte reprogramming into iNSCs. Here, we show that mature astrocytes could be directly converted into iNSCs by a single transcription factor, Oct4, and that the iNSCs displayed typical neurosphere morphology, authentic NSC gene expression, self-renewal capacity, and multipotency. Strikingly, Oct4-driven reprogramming of astrocytes into iNSCs was potentiated with continuous sonic hedgehog (Shh) stimulation, as demonstrated by a sped-up reprogramming and increased conversion efficiency. Moreover, the iNSC-derived neurons possessed functionality as neurons. Importantly, crosstalk between Sox2/Shh-targeted downstream signals and phosphatidylinositol 3-kinase/cyclin-dependent kinase 2/Smad ubiquitin regulatory factor 2 (PI3K/Cdk2/Smurf2) signaling is likely involved in the mechanisms underlying this cellular event. The highly efficient reprogramming of astrocytes to generate iNSCs will provide an alternative therapeutic approach for SCI using autologous cells.
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http://dx.doi.org/10.1016/j.ymthe.2019.05.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6698197PMC
August 2019

Chitinases Play a Key Role in Stipe Cell Wall Extension in the Mushroom .

Appl Environ Microbiol 2019 08 18;85(15). Epub 2019 Jul 18.

Jiangsu Key Laboratory for Microbes and Microbial Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing, People's Republic of China

The elongation growth of the mushroom stipe is a characteristic but not well-understood morphogenetic event of basidiomycetes. We found that extending native stipe cell walls of were associated with the release of -acetylglucosamine and chitinbiose and with chitinase activity. Two chitinases among all detected chitinases from , ChiE1 and ChiIII, reconstituted heat-inactivated stipe wall extension and released -acetylglucosamine and chitinbiose. Interestingly, both ChiE1 and ChiIII hydrolyze insoluble crystalline chitin powder, while other chitinases do not, suggesting that crystalline chitin components of the stipe cell wall are the target of action for ChiE1 and ChiIII. ChiE1- or ChiIII-reconstituted heat-inactivated stipe walls showed maximal extension activity at pH 4.5, consistent with the optimal pH for native stipe wall extension ; ChiE1- or ChiIII-reconstituted heat-inactivated stipe wall extension activities were associated with stipe elongation growth regions; and the combination of ChiE1 and ChiIII showed a synergism to reconstitute heat-inactivated stipe wall extension at a low action concentration. Field emission scanning electron microscopy (FESEM) images showed that the inner surface of acid-induced extended native stipe cell walls and ChiE1- or ChiIII-reconstituted extended heat-inactivated stipe cell walls exhibited a partially broken parallel microfibril architecture; however, these broken transversely arranged microfibrils were not observed in the unextended stipe cell walls that were induced by neutral pH buffer or heat inactivation. Double knockdown of ChiE1 and ChiIII resulted in the reduction of stipe elongation, mycelium growth, and heat-sensitive cell wall extension of native stipes. These results indicate a chitinase-hydrolyzing mechanism for stipe cell wall extension. A remarkable feature in the development of basidiomycete fruiting bodies is stipe elongation growth that results primarily from manifold cell elongation. Some scientists have suggested that stipe elongation is the result of enzymatic hydrolysis of cell wall polysaccharides, while other scientists have proposed the possibility that stipe elongation results from nonhydrolytic disruption of the hydrogen bonds between cell wall polysaccharides. Here, we show direct evidence for a chitinase-hydrolyzing mechanism of stipe cell wall elongation in the model mushroom that is different from the expansin nonhydrolysis mechanism of plant cell wall extension. We presumed that in the growing stipe cell walls, parallel chitin microfibrils are tethered by β-1,6-branched β-1,3-glucans, and that the breaking of the tether by chitinases leads to separation of these microfibrils to increase their spacing for insertion of new synthesized chitin and β-1,3-glucans under turgor pressure .
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http://dx.doi.org/10.1128/AEM.00532-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6643254PMC
August 2019

KIBRA controls exosome secretion via inhibiting the proteasomal degradation of Rab27a.

Nat Commun 2019 04 9;10(1):1639. Epub 2019 Apr 9.

Department of Neurology, Shandong Provincial Hospital affiliated to Shandong University, 250021, Jinan, Shandong, China.

Exosomes are nanosized membrane vesicles released from cells after fusion of multivesicular bodies (MVBs) with the plasma membrane (PM) and play important roles in intercellular communication and numerous biological processes. However, the molecular mechanisms regulating exosome secretion remain poorly understood. Here we identify KIBRA as an adaptor-like protein that stabilizes Rab27a, which in turn controls exosome secretion both in vitro and in vivo. Knockdown or overexpression of KIBRA in neuronal and podocyte cell lines leads to a decrease or increase of exosome secretion, respectively, and KIBRA depletion increases MVB size and number. Comparing protein profiles between KIBRA knockout and wild-type mouse brain showed significantly decreased Rab27a, a small GTPase that regulates MVB-PM docking. Rab27a is stabilized by interacting with KIBRA, which prevents ubiquitination and degradation via the ubiquitin-proteasome pathway. In conclusion, we show that KIBRA controls exosome secretion via inhibiting the proteasomal degradation of Rab27a.
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http://dx.doi.org/10.1038/s41467-019-09720-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6456494PMC
April 2019