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1.
Sci Rep ; 13(1): 5331, 2023 04 01.
Article in English | MEDLINE | ID: mdl-37005450

ABSTRACT

GDP-amylose transporter protein 1 (SLC35C1) plays an important role in many types of cancer. Therefore, it is clinically important to further investigate the expression profile of SLC35C1 in human tumors to provide new molecular clues for the pathogenesis of glioma. In this study, we performed a comprehensive pan-cancer analysis of SLC35C1 using a series of bioinformatics approaches and validated its differential tissue expression and biological function. The results showed that SLC35C1 was aberrantly expressed in different types of tumors and significantly correlated with overall survival (OS) and progression-free interval (PFI). More importantly, the expression level of SLC35C1 was closely correlated with Tumor Microenvironment (TME), immune infiltration and immune-related genes. In addition, we found that SLC35C1 expression was also closely related to Tumor Mutation Burden (TMB), Microsatellite Instability (MSI) and antitumor drug sensitivity in various cancer types. Functional bioinformatics analysis indicated that SLC35C1 may be involved in multiple signaling pathways and biological processes in glioma. Based on SLC35C1 expression, a risk factor model was found to predict OS of glioma. In addition, in vitro experiments showed that SLC35C1 knockdown significantly inhibited the proliferation, migration and invasive ability of glioma cells, while SLC35C1 overexpression promoted proliferation, migration, invasion and colony formation of glioma cells. Finally, quantitative real-time PCR confirmed that SLC35C1 was highly expressed in gliomas.


Subject(s)
Glioma , Humans , Prognosis , Glioma/genetics , Amylose , Computational Biology , Biomarkers , Tumor Microenvironment/genetics , Monosaccharide Transport Proteins
2.
Int J Ophthalmol ; 15(2): 197-204, 2022.
Article in English | MEDLINE | ID: mdl-35186677

ABSTRACT

AIM: To study the braking effectiveness of artesunate on transforming growth factor (TGF)-ß2 mediated epithelial-mesenchymal transition (EMT) in retinal pigment epithelium (RPE) in vitro. METHODS: The fostered ARPE-19 cells were processed with artesunate alone or combined with the TGF-ß2. The CCK-8 examination was utilized to test the cell propagation. Cell migration was detected by scratch as well as the Transwell examination. The EMT characters and activation of PI3K/Akt signal channel were estimated by Western blotting and immunofluorescence. The Western blotting was utilized in order to confirm the vitreous of controls as well as patients with proliferative vitreoretinopathy (PVR) were collected and the levels of PI3K, phospho-PI3K, Akt. RESULTS: Disposal of ARPE-19 cells with artesunate (50-150 µmol/L) obviously suppressed their propagation and immigration, which dependent on the concentration and time. Artesunate suppressed the EMT which was induced by TGF-ß2 in ARPE-19 cells through sustaining the expression of vimentin and α-SMA through the suppression of PI3K, phospho-PI3K, phospho-Akt and Akt. Levels of PI3K, phospho-PI3K, AKT and phospho-Akt was increased in the vitreous in PVR (P<0.05). CONCLUSION: Such findings indicate that PI3K/Akt signal channel is highly activated in vitreous of PVR. Artesuante is an operative depressor of the propagation, immigration and TGF-ß2-mediated EMT of ARPE-19 cells by reduced the expression of PI3K/Akt channel.

3.
IEEE Trans Cybern ; 52(2): 836-848, 2022 Feb.
Article in English | MEDLINE | ID: mdl-32413948

ABSTRACT

In this article, we study the distributed resilient cooperative control problem for directed networked Lagrangian systems under denial-of-service (DoS) attacks. The DoS attacks will block the communication channels between the agents. Compared with the existing methods for the linear networked systems, the considered nonlinear networked Lagrangian systems with asymmetric channels under DoS attacks are more challenging and still not well explored. In order to solve this problem, a novel resilient cooperative control scheme is proposed by using the sampling control approach. Sufficient conditions are first derived in the absence of DoS attacks according to a multidimensional small-gain scheme. Then, in the presence of DoS attacks, the proposed resilient scheme works in a switching manner. Inspired by multidimensional small-gain techniques, the Lyapunov approach is used to analyze the closed-loop system, which enables us to establish sufficient stability conditions for the control gains in terms of the duration and frequency of the DoS attacks.


Subject(s)
Communication
4.
IEEE Trans Cybern ; 52(8): 8493-8503, 2022 Aug.
Article in English | MEDLINE | ID: mdl-34133291

ABSTRACT

In this article, we consider the resilience problem in the presence of communication faults encountered in distributed secondary voltage and frequency control of an islanded alternating current microgrid. Such faults include the partial failure of communication links and some classes of data manipulation attacks. This practical and important yet challenging issue has been taken into limited consideration by existing approaches, which commonly assume that the measurement or communication between the distributed generations (DGs) is ideal or satisfies some restrictive assumptions. To achieve communication resilience, a novel adaptive observer is first proposed for each individual DG to estimate the desired reference voltage and frequency under unknown communication faults. Then, to guarantee the stability of the closed-loop system, voltage and frequency restoration, and accurate power sharing regardless of unknown communication faults, sufficient conditions are derived. Some simulation results are presented to verify the effectiveness of the proposed secondary control approach.

5.
Tree Physiol ; 42(5): 1016-1028, 2022 05 09.
Article in English | MEDLINE | ID: mdl-34918132

ABSTRACT

Mangrove ecosystems are vulnerable to rising sea levels. When the sea level rises, the plants are exposed to increased salinity and tidal submergence. In Taiwan, the mangrove species Kandelia obovata and Rhizophora stylosa grow in different habitats and at different elevations. To understand the response of photosynthesis to salinity and submergence in mangroves adapted to different tidal elevations, gas exchange and chlorophyll fluorescence parameters were measured in K. obovata and R. stylosa under different salinity (20 and 40‰) and submergence treatments. The period of light induction of photosynthesis for the two mangrove species was >60 min. In the induction process, the increase in photosystem efficiency was faster than the increase in stomatal opening, but CO2 fixation efficiency was restricted by stomatal conductance. The constraint of stomatal opening speed is related to the conservative water-use strategy developed in response to mangrove environments. Submergence increased the photosynthetic rate of K. obovata, but not that of R. stylosa. Although R. stylosa was more salt tolerant than K. obovata, R. stylosa was not submergence tolerant in a high-salinity environment, which may be the reason for the higher intertidal elevations observed for R. stylosa in comparison with K. obovata. The photosynthetic rate and energy-dependent quenching (qE) of the two mangroves presented a negative relationship with photoinhibition, and high-salt treatment simultaneously reduced photosynthetic rate and qE. A decrease in the photosynthetic rate increased excess energy, whereas a decrease in qE decreased photoprotection; both increased photoinhibition. As the degree of photoinhibition can be easily measured in the field, it is a useful ecological monitoring index that provides a suitable reference for mangrove restoration, habitat construction and ecological monitoring.


Subject(s)
Rhizophoraceae , Adaptation, Physiological , Ecosystem , Photosynthesis , Rhizophoraceae/physiology , Salinity
6.
Exp Eye Res ; 213: 108859, 2021 12.
Article in English | MEDLINE | ID: mdl-34822854

ABSTRACT

Proliferative vitreoretinopathy (PVR) is the main cause of retinal detachment surgery failure. The epithelial-mesenchymal transition (EMT) induced by transforming growth factor (TGF-ß2) plays an important role in the development of PVR. Artesunate has been widely studied as a treatment for ophthalmic diseases because of its antioxidant, anti-inflammatory, antiapoptotic and antiproliferative properties. The purpose of this study was to investigate the effects of artesunate on the TGF-ß2-induced EMT in ARPE-19 cells and PVR development. We found that artesunate inhibited the proliferation and contraction of ARPE-19 cells after the EMT and the autocrine effects of TGF-ß2 on ARPE-19 cells. Additionally, the levels of Smad3 and p-Smad3 were increased in clinical samples, and artesunate decreased the levels of Smad3 and p-Smad3 in ARPE-19 cells treated with TGF-ß2. Artesunate also inhibited the occurrence and development of PVR in vivo. In summary, artesunate inhibits the occurrence and development of PVR by inhibiting the EMT in ARPE-19 cells.


Subject(s)
Antimalarials/therapeutic use , Artesunate/therapeutic use , Epithelial-Mesenchymal Transition/drug effects , Retinal Pigment Epithelium/drug effects , Smad3 Protein/antagonists & inhibitors , Transforming Growth Factor beta2/antagonists & inhibitors , Vitreoretinopathy, Proliferative/drug therapy , Animals , Antimalarials/pharmacology , Artesunate/pharmacology , Blotting, Western , Cell Cycle/physiology , Cell Line , Cell Movement/drug effects , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Humans , Intravitreal Injections , Rabbits , Retinal Pigment Epithelium/metabolism , Signal Transduction/drug effects , Smad3 Protein/metabolism , Transforming Growth Factor beta2/metabolism , Vitreoretinopathy, Proliferative/metabolism
7.
Insect Sci ; 28(3): 718-734, 2021 Jun.
Article in English | MEDLINE | ID: mdl-32428381

ABSTRACT

The Asian citrus psyllid, Diaphorina citri is the principal vector of huanglongbing, which transmits Candidatus Liberibacter asiaticus. Trehalase is a key enzyme involved in trehalose hydrolysis and plays an important role in insect growth and development. The specific functions of this enzyme in D. citri have not been determined. In this study, three trehalase genes (DcTre1-1, DcTre1-2, and DcTre2) were identified based on the D. citri genome database. Bioinformatic analysis showed that DcTre1-1 and DcTre1-2 are related to soluble trehalase, whereas DcTre2 is associated with membrane-bound trehalase. Spatiotemporal expression analysis indicated that DcTre1-1 and DcTre1-2 had the highest expression levels in the head and wing, respectively, and DcTre2 had high expression levels in the fat body. Furthermore, DcTre1-1 and DcTre1-2 expression levels were induced by 20-hydroxyecdysone and juvenile hormone Ⅲ, but DcTre2 was unaffected. The expression levels of DcTre1-1, DcTre1-2, and DcTre2 were significantly upregulated, which resulted in high mortality after treatment with validamycin. Trehalase activities and glucose contents were downregulated, but the trehalose content increased after treatment with validamycin. In addition, the expression levels of chitin metabolism-related genes significantly decreased at 24 and 48 h after treatment with validamycin. Furthermore, silencing of DcTre1-1, DcTre1-2, and DcTre2 reduced the expression levels of chitin metabolism-related genes and led to a malformed phenotype of D. citri. These results indicate that D. citri trehalase plays an essential role in regulating chitin metabolism and provides a new target for control of D. citri.


Subject(s)
Hemiptera , Trehalase , Animals , Chitin/metabolism , Gene Expression Regulation , Genes, Insect , Hemiptera/genetics , Hemiptera/metabolism , Inositol/analogs & derivatives , Inositol/pharmacology , Pest Control , RNA Interference , Trehalase/drug effects , Trehalase/genetics , Trehalase/metabolism , Trehalose/metabolism
8.
EMBO Mol Med ; 13(1): e12828, 2021 01 11.
Article in English | MEDLINE | ID: mdl-33159417

ABSTRACT

To circumvent the devastating pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, a humanized decoy antibody (ACE2-Fc fusion protein) was designed to target the interaction between viral spike protein and its cellular receptor, angiotensin-converting enzyme 2 (ACE2). First, we demonstrated that ACE2-Fc could specifically abrogate virus replication by blocking the entry of SARS-CoV-2 spike-expressing pseudotyped virus into both ACE2-expressing lung cells and lung organoids. The impairment of viral entry was not affected by virus variants, since efficient inhibition was also observed in six SARS-CoV-2 clinical strains, including the D614G variants which have been shown to exhibit increased infectivity. The preservation of peptidase activity also enables ACE2-Fc to reduce the angiotensin II-mediated cytokine cascade. Furthermore, this Fc domain of ACE2-Fc was shown to activate NK cell degranulation after co-incubation with Spike-expressing H1975 cells. These promising characteristics potentiate the therapeutic prospects of ACE2-Fc as an effective treatment for COVID-19.


Subject(s)
Antibodies, Monoclonal, Humanized/pharmacology , Antibodies, Viral/pharmacology , COVID-19/prevention & control , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/immunology , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/immunology , Animals , Antibodies, Monoclonal, Humanized/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Chlorocebus aethiops , HEK293 Cells , Host-Pathogen Interactions/drug effects , Humans , Killer Cells, Natural/drug effects , Killer Cells, Natural/immunology , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/pharmacology , SARS-CoV-2/immunology , SARS-CoV-2/physiology , Vero Cells
9.
IEEE Trans Cybern ; 51(1): 199-209, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32217493

ABSTRACT

In this article, we address the bearing-only formation control problem of 3-D networked robotic systems with parametric uncertainties. The contributions of this article are two-fold: 1) the bearing-rigid theory is extended to solve the nonlinear robotic systems with the Euler-Lagrange-like model and 2) a novel almost global stable distributed bearing-only formation control law is proposed for the nonlinear robotic systems. Specifically, the robotic systems subject to nonholonomic constraints and dynamics are first transformed into a Euler-Lagrange-like model. By exploring the bearing-rigid graph theory, a backstepping approach is used to design the distributed formation controller. Simulations for 3-D robotics are given to demonstrate the effectiveness of the proposed control law. Compared to the distance-rigid formation control approach, the bearing-rigid approach guarantees almost global stability while naturally excluding flip ambiguities.

10.
Mar Pollut Bull ; 162: 111797, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33183750

ABSTRACT

This study reports on a sediment toxicity test developed with a native amphipod strain of Ptilohyale barbicornis where sediments from 10 estuarine stations along the western coastline of Taiwan were evaluated with respect to trace metals and PAHs. The test was validated by determining dose-response relationships for aqueous copper, and cadmium and sodium dodecyl sulfate as well as copper-spiked sediment, showing a sensitivity of P. barbicornis indicating its capability serving as a toxicity test species. A significant negative correlation between growth effects after 28 days of exposure to field-collected contaminated sediments and PAHs concentrations was observed. Similarly, the chronic toxicity test showed that growth was mostly inhibited compared to controls, body lengths in particular being significantly different from controls (p < 0.05). Various estuarine sediment pollutants in the quality guidelines can be further evaluated using P. barbicornis to understand their comprehensive biological effects and ecological risks.


Subject(s)
Amphipoda , Water Pollutants, Chemical , Animals , Environmental Monitoring , Geologic Sediments , Taiwan , Toxicity Tests , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicity
11.
Hepatobiliary Pancreat Dis Int ; 20(3): 251-261, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33129711

ABSTRACT

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most highly malignant tumors. Liver tumor-initiating cells (LTICs) have been considered to contribute to HCC progression and metastasis. ATP-citrate lyase (ACLY), as a key enzyme for de novo lipogenesis, has been reported to be upregulated in various tumors. However, its expression and role in HCC and LTICs remain unknown. METHODS: The expressions of ACLY in HCC tissues were detected by quantitative real-time PCR (qRT-PCR), Western blotting and immunohistochemistry. Kaplan-Meier curves and Chi-square test were used to determine the clinical significance of ACLY expression in HCC patients. A series of assays were performed to determine the function of ACLY on stemness, migration and invasion of HCC cells. Luciferase reporter assay, Western blotting and immunoprecipitation were used to study the regulation of the Wnt/ß-catenin signaling by ACLY. Rescue experiments were performed to investigate whether ß-catenin was the mediator of ACLY-regulated stemness and migration in HCC cells. RESULTS: ACLY was highly expressed in HCC tissues and LTICs. Overexpression of ACLY was significantly correlated with poor prognosis, progression and metastasis of HCC patients. Knockdown of ACLY remarkably suppressed stemness properties, migration and invasion in HCC cells. Mechanistically, ACLY could regulate the canonical Wnt pathway by affecting the stability of ß-catenin, and Lys49 acetylation of ß-catenin might mediate ACLY-regulated ß-catenin level in HCC cells. CONCLUSIONS: ACLY is a potent regulator of Wnt/ß-catenin signaling in modulating LTICs stemness and metastasis in HCC. ACLY may serve as a new target for the diagnosis and treatment of HCC.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , ATP Citrate (pro-S)-Lyase/genetics , Adenosine Triphosphate , Carcinoma, Hepatocellular/genetics , Cell Line, Tumor , Cell Proliferation , Gene Expression Regulation, Neoplastic , Humans , Liver Neoplasms/genetics , Multienzyme Complexes , Oxo-Acid-Lyases , Wnt Signaling Pathway , beta Catenin/genetics
12.
Neuropsychopharmacology ; 46(4): 721-730, 2021 03.
Article in English | MEDLINE | ID: mdl-33096543

ABSTRACT

This study examined the klotho (KL) longevity gene polymorphism rs9315202 and psychopathology, including posttraumatic stress disorder (PTSD), depression, and alcohol-use disorders, in association with advanced epigenetic age in three postmortem cortical tissue regions: dorsolateral and ventromedial prefrontal cortices and motor cortex. Using data from the VA National PTSD Brain Bank (n = 117), we found that rs9315202 interacted with PTSD to predict advanced epigenetic age in motor cortex among the subset of relatively older (>=45 years), white non-Hispanic decedents (corrected p = 0.014, n = 42). An evaluation of 211 additional common KL variants revealed that only variants in linkage disequilibrium with rs9315202 showed similarly high levels of significance. Alcohol abuse was nominally associated with advanced epigenetic age in motor cortex (p = 0.039, n = 114). The rs9315202 SNP interacted with PTSD to predict decreased KL expression via DNAm age residuals in motor cortex among older white non-Hispanics decedents (indirect ß = -0.198, p = 0.027). Finally, in dual-luciferase enhancer reporter system experiments, we found that inserting the minor allele of rs9315202 in a human kidney cell line HK-2 genomic DNA resulted in a change in KL transcriptional activities, likely operating via long noncoding RNA in this region. This was the first study to examine multiple forms of psychopathology in association with advanced DNA methylation age across several brain regions, to extend work concerning the association between rs9315202 and advanced epigenetic to brain tissue, and to identify the effects of rs9315202 on KL gene expression. KL augmentation holds promise as a therapeutic intervention to slow the pace of cellular aging, disease onset, and neuropathology, particularly in older, stressed populations.


Subject(s)
Glucuronidase/genetics , Stress Disorders, Post-Traumatic , Aged , Alleles , DNA Methylation , Epigenesis, Genetic , Epigenomics , Humans , Klotho Proteins , Middle Aged , Stress Disorders, Post-Traumatic/genetics
13.
Chem Res Toxicol ; 33(8): 2208-2217, 2020 08 17.
Article in English | MEDLINE | ID: mdl-32633501

ABSTRACT

Nomilin is a furan-containing triterpenoid isolated from the medicinal plants of citrus. The aim of this study was to investigate the in vitro and in vivo bioactivation of nomilin and the role in nomilin-induced hepatotoxicity. Microsomal incubations of nomilin supplemented with NADPH and GSH or NAL resulted in the detection of six conjugates (M1-M6). The structures of the metabolites were characterized based on LC-HRMS and NMR. Nomilin was bioactivated to a reactive cis-butene-dial (BDA) intermediate dependent on NADPH, and this intermediate suffered from the reaction with the nucleophiles (GSH and NAL) to form stable adducts. M1-M4 were identified as pyrrole derivatives, and M5 and M6 were pyrrolinone derivatives. M1 was further chemically synthesized and characterized by 13C NMR spectroscopy. M1 was the major metabolite detected in mice bile. Pretreatment with ketoconazole significantly reduced the formation of M1 in mice bile, while pretreatment with rifampicin significantly increased the formation of M1. Chemical inhibition together with recombinant human CYP450 phenotyping demonstrated that CYP3A4 was the major enzyme contributing to the bioactivation of nomilin. Toxicity study suggested that nomilin displayed dose-dependent liver injury in mice, while tetrahydro-nomilin was found to be nonhepatotoxic. Pretreatment with ketoconazole prevented mice from nomilin-induced liver injury. The liver injury induced by nomilin was deteriorated when the mice were pretreated with rifampicin. These findings provide evidence that CYP3A4-mediated bioactivation was indispensable in nomilin-induced hepatotoxicity.


Subject(s)
Benzoxepins/toxicity , Cytochrome P-450 CYP3A/metabolism , Limonins/toxicity , Liver/drug effects , Administration, Oral , Animals , Benzoxepins/administration & dosage , Female , Humans , Limonins/administration & dosage , Liver/metabolism , Male , Mice , Mice, Inbred ICR , Microsomes, Liver/chemistry , Microsomes, Liver/metabolism
14.
Int J Biochem Cell Biol ; 123: 105747, 2020 06.
Article in English | MEDLINE | ID: mdl-32315771

ABSTRACT

OBJECTIVE: To investigate circular RNA (circRNA) expression profile via microarray, and further assess the potential of candidate circRNAs as biomarkers in Alzheimer's disease (AD). METHODS: CircRNA expression profile in cerebrospinal fluid from 8 AD patients and 8 control (Ctrl) subjects was assessed by microarray. Subsequently, 10 candidate circRNAs from microarray were validated by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in cerebrospinal fluid from 80 AD patients and 40 Ctrl subjects. RESULTS: By microarray, 112 circRNAs were upregulated and 51 circRNAs were downregulated in AD patients compared with Ctrl subjects, and these circRNAs were enriched in AD related pathways such as neurotrophin signaling pathway, natural killer cell mediated cytotoxicity and cholinergic synapse. By RT-qPCR, circ-LPAR1, circ-AXL and circ-GPHN were increased, whereas circ-PCCA, circ-HAUS4, circ-KIF18B and circ-TTC39C were decreased in AD patients compared with Ctrl subjects, and these circRNAs were disclosed to predict AD risk by receiver operating characteristics curve analysis. Further forward-stepwise multivariate logistic regression revealed that circ-AXL, circ-GPHN, circ-ITPR3, circ-PCCA and cic-TTC39C were independent predictive factors for AD risk. Besides, in AD patients, circ-AXL and circ-GPHN negatively correlated, while circ-PCCA and circ-HAUS4 positively correlated with mini-mental state examination score; Circ-AXL negatively correlated, while circ-PCCA, circ-HAUS4 and circ-KIF18B positively correlated with Aß42; Circ-AXL and circ-GPHN positively correlated, whereas circ-HAUS4 negatively correlated with t-tau; Circ-AXL positively correlated with p-tau. CONCLUSION: Our study provides an overview of circRNA expression profile in AD, and identifies that circ-AXL, circ-GPHN and circ-PCCA hold clinical implications for guiding disease management in AD patients.


Subject(s)
Alzheimer Disease/cerebrospinal fluid , Amyloid beta-Peptides/cerebrospinal fluid , Peptide Fragments/cerebrospinal fluid , RNA, Circular/cerebrospinal fluid , Signal Transduction/genetics , tau Proteins/cerebrospinal fluid , Aged , Alzheimer Disease/genetics , Amyloid beta-Peptides/genetics , Amyloid beta-Peptides/metabolism , Biomarkers/cerebrospinal fluid , Disease Progression , Down-Regulation , Female , Gene Ontology , Humans , Killer Cells, Natural/immunology , Logistic Models , Male , MicroRNAs/cerebrospinal fluid , MicroRNAs/genetics , Microarray Analysis , Middle Aged , Nerve Growth Factors/cerebrospinal fluid , Nerve Growth Factors/genetics , Non-Neuronal Cholinergic System/genetics , Peptide Fragments/genetics , Peptide Fragments/metabolism , RNA, Circular/genetics , ROC Curve , Real-Time Polymerase Chain Reaction , Up-Regulation , tau Proteins/genetics , tau Proteins/metabolism
15.
FASEB J ; 34(6): 7234-7246, 2020 06.
Article in English | MEDLINE | ID: mdl-32347987

ABSTRACT

There is an unmet need for treatments for diseases associated with aging. The antiaging, life-extending, and cognition-enhancing protein Klotho is neuroprotective due to its anti-inflammatory, antioxidative, and pro-myelinating effects. In addition, Klotho is also a tumor suppressor and has beneficial roles in multiple organs. Klotho is downregulated as part of the aging process. Thus, upregulating Klotho in the brain may lead to novel therapeutics to people suffering or at risk for neurodegenerative diseases such as Alzheimer's, Parkinson's, and amyotrophic lateral sclerosis, and demyelinating diseases such as multiple sclerosis. We attempted to upregulate Klotho for its beneficial effects in the brain and elsewhere. Here, we describe a method to specifically activate Klotho gene expression. To accomplish this task, we designed zinc finger proteins (ZFPs) targeting within -300 bps of the human Klotho promoter. We designed the ZPF constructs either de novo from modular building blocks, or modified sequences from the natural endogenous Egr1 transcription factor backbone structure. Egr1 is known to upregulate Klotho expression. We tested the transcriptional activation effects of these ZFPs in a dual luciferase coincidence reporter system under the control of 4-kb promoter of human Klotho in stable HEK293 cells and in HK-2 cells that express Klotho protein endogenously. We found that the best ZFPs are the de novo designed ones targeting -250 bps of Klotho promoter and one of the Egr1-binding sites. We further enhanced Klotho's activation using p65-Rta transcriptional activation domains in addition to VP64. These upregulation approaches could be useful for studying Klotho's protective effects and designing Klotho boosting therapeutics for future in vivo experiments.


Subject(s)
Early Growth Response Protein 1/genetics , Glucuronidase/genetics , Promoter Regions, Genetic/genetics , Zinc Fingers/genetics , Aging/genetics , Binding Sites/genetics , Brain/metabolism , Cell Line , Cognition/physiology , Gene Expression/genetics , HEK293 Cells , Humans , Klotho Proteins , Luciferases/genetics , Neurodegenerative Diseases/genetics , Neurodegenerative Diseases/metabolism , Transcriptional Activation/genetics , Up-Regulation/genetics
16.
Insects ; 11(3)2020 Mar 07.
Article in English | MEDLINE | ID: mdl-32156093

ABSTRACT

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important transmission vector of the citrus greening disease Candidatus Liberibacter asiaticus (CLas). The D. citri midgut exhibits an important tissue barrier against CLas infection. However, the molecular mechanism of the midgut response to CLas infection has not been comprehensively elucidated. In this study, we identified 778 differentially expressed genes (DEGs) in the midgut upon CLas infection, by comparative transcriptome analyses, including 499 upregulated DEGs and 279 downregulated DEGs. Functional annotation analysis showed that these DEGs were associated with ubiquitination, the immune response, the ribosome, endocytosis, the cytoskeleton and insecticide resistance. KEGG enrichment analysis revealed that most of the DEGs were primarily involved in endocytosis and the ribosome. A total of fourteen DEG functions were further validated by reverse transcription quantitative PCR (RT-qPCR). This study will contribute to our understanding of the molecular interaction between CLas and D. citri.

17.
PLoS One ; 15(1): e0226382, 2020.
Article in English | MEDLINE | ID: mdl-31929539

ABSTRACT

Klotho is an age-extending, cognition-enhancing protein found to be down-regulated in aged mammals when age-related diseases start to appear. Low levels of Klotho occur in neurodegenerative diseases, kidney disease and many cancers. Many normal and pathologic processes involve the proteolytic shedding of membrane proteins. Transmembrane (TM) Klotho contains two homologous domains, KL1 and KL2 with homology to glycosidases. After shedding by ADAM 10 and 17, a shed Klotho isoform is released into serum and urine by the kidney, and into the CSF by the choroid plexus. We previously reported that human Klotho contains two major cleavage sites. However, the exact cleavage site responsible for the cleavage between the KL1 and KL2 domains remains unknown for the human Klotho, and both sites are unknown for mouse Klotho. In this study, we aimed to identify the cleavage sites leading to the shed forms of human and mouse Klotho. Mutations in the region close to the TM domain of mouse Klotho result in the reduced shedding of the 130 kD (KL1+KL2) and 70 kD (KL1) fragments, suggesting that the cleavage site lies within the mutated region. We further identified the cleavage sites responsible for the cleavage between KL1 and KL2 of human and mouse Klotho. Moreover, mutated Klotho proteins have similar subcellular localization patterns as wild type Klotho. Finally, in an FGF23 functional assay, all Klotho mutants with a nine amino acid deletion can also function as an FGFR1 co-receptor for FGF23 signaling, however, the signaling activity was greatly reduced. The study provides new and important information on Klotho shedding, and paves the way for studies aimed to distinguish between the distinct roles of the various isoforms of Klotho.


Subject(s)
Glucuronidase/metabolism , ADAM10 Protein/metabolism , Amino Acid Sequence , Animals , COS Cells , Chlorocebus aethiops , Fibroblast Growth Factor-23 , Fibroblast Growth Factors/metabolism , Glucuronidase/chemistry , Glucuronidase/genetics , HEK293 Cells , Humans , Klotho Proteins , Mice , Microscopy, Fluorescence , Mutagenesis , Protein Domains , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/metabolism , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Sequence Alignment , Signal Transduction
18.
FASEB J ; 34(2): 2087-2104, 2020 02.
Article in English | MEDLINE | ID: mdl-31907991

ABSTRACT

Proteinuria is associated with renal function decline and cardiovascular mortality. This association may be attributed in part to alterations of Klotho expression induced by albuminuria, yet the underlying mechanisms are unclear. The presence of albumin decreased Klotho expression in the POD-ATTAC mouse model of proteinuric kidney disease as well as in kidney epithelial cell lines. This downregulation was related to both decreased Klotho transcription and diminished protein half-life, whereas cleavage by ADAM proteases was not modified. The regulation was albumin specific since it was neither observed in the analbuminemic Col4α3-/- Alport mice nor induced by exposure of kidney epithelial cells to purified immunoglobulins. Albumin induced features of ER stress in renal tubular cells with ATF3/ATF4 activation. ATF3 and ATF4 induction downregulated Klotho through altered transcription mediated by their binding on the Klotho promoter. Inhibiting ER stress with 4-PBA decreased the effect of albumin on Klotho protein levels without altering mRNA levels, thus mainly abrogating the increased protein degradation. Taken together, albuminuria decreases Klotho expression through increased protein degradation and decreased transcription mediated by ER stress induction. This implies that modulating ER stress may improve proteinuria-induced alterations of Klotho expression, and hence renal and extrarenal complications associated with Klotho loss.


Subject(s)
Activating Transcription Factor 3/metabolism , Albuminuria/metabolism , Down-Regulation , Endoplasmic Reticulum Stress , Glucuronidase/biosynthesis , Kidney Tubules/metabolism , Transcription, Genetic , Activating Transcription Factor 3/genetics , Albuminuria/genetics , Albuminuria/pathology , Animals , Autoantigens/genetics , Autoantigens/metabolism , Collagen Type IV/genetics , Collagen Type IV/metabolism , Glucuronidase/genetics , Humans , Kidney Tubules/pathology , Klotho Proteins , Mice , Mice, Knockout
19.
Cancers (Basel) ; 13(1)2020 Dec 31.
Article in English | MEDLINE | ID: mdl-33396393

ABSTRACT

Oncogenic mutations of epidermal growth factor receptor (EGFR) are responsive to targeted tyrosine kinase inhibitor (TKI) treatment in non-small-cell lung cancer (NSCLC). However, NSCLC patients harboring activating EGFR mutations inevitably develop resistance to TKIs. The acquired EGFR C797S mutation is a known mechanism that confers resistance to third-generation EGFR TKIs such as AZD9291. In this work, we employed CRISPR/Cas9 genome-editing technology to knock-in the EGFR C797S mutation into an NSCLC cell line harboring EGFR L858R/T790M. The established cell model was used to investigate the biology and treatment strategy of acquired EGFR C797S mutations. Transcriptome and proteome analyses revealed that the differentially expressed genes/proteins in the cells harboring the EGFR C797S mutation are associated with a mesenchymal-like cell state with elevated expression of AXL receptor tyrosine kinase. Furthermore, we presented evidence that inhibition of AXL is effective in slowing the growth of NSCLC cells harboring EGFR C797S. Our findings suggest that AXL inhibition could be a second-line or a potential adjuvant treatment for NSCLC harboring the EGFR C797S mutation.

20.
J Mol Neurosci ; 69(2): 264-285, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31250273

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by the loss of motor neurons in the brain and spinal cord. ALS neuropathology is associated with increased oxidative stress, excitotoxicity, and inflammation. We and others reported that the anti-aging and cognition-enhancing protein Klotho is a neuroprotective, antioxidative, anti-inflammatory, and promyelinating protein. In mice, its absence leads to an extremely shortened life span and to multiple phenotypes resembling human aging, including motor and hippocampal neurodegeneration and cognitive impairment. In contrast, its overexpression extends life span, enhances cognition, and confers resistance against oxidative stress; it also reduces premature mortality and cognitive and behavioral abnormalities in an animal model for Alzheimer's disease (AD). These pleiotropic beneficial properties of Klotho suggest that Klotho could be a potent therapeutic target for preventing neurodegeneration in ALS. Klotho overexpression in the SOD1 mouse model of ALS resulted in delayed onset and progression of the disease and extended survival that was more prominent in females than in males. Klotho reduced the expression of neuroinflammatory markers and prevented neuronal loss with the more profound effect in the spinal cord than in the motor cortex. The effect of Klotho was accompanied by reduced expression of proinflammatory cytokines and enhanced the expression of antioxidative and promyelinating factors in the motor cortex and spinal cord of Klotho × SOD1 compared to SOD1 mice. Our study provides evidence that increased levels of Klotho alleviate ALS-associated pathology in the SOD1 mouse model and may serve as a basis for developing Klotho-based therapeutic strategies for ALS.


Subject(s)
Amyotrophic Lateral Sclerosis/genetics , Glucuronidase/genetics , Superoxide Dismutase-1/genetics , Amyotrophic Lateral Sclerosis/metabolism , Animals , Cells, Cultured , Cytokines/genetics , Cytokines/metabolism , Female , Glucuronidase/metabolism , Klotho Proteins , Longevity/genetics , Male , Mice , Mice, Inbred C57BL , Motor Cortex/cytology , Motor Cortex/metabolism , Neuroglia/metabolism , Neurons/metabolism
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