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1.
J Med Chem ; 67(7): 5800-5812, 2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38560986

ABSTRACT

Near-infrared (NIR) fluorescence imaging has attracted much attention in image-guided interventions with unique advantages. However, the clinical translation rate of fluorescence probes is extremely low, primarily due to weak lesion signal contrast and poor specificity. To address this dilemma, a series of small-molecule near-infrared fluorescence probes have been designed for tumor imaging. Among them, YQ-04-03 showed notable optical stability and remarkable sensitivity toward tumor targeting. Moreover, within a specific concentration and time range against oxidizing reducing agents and laser, it demonstrated better stability than ICG. The retention time of YQ-04-03 in tumors was significantly longer compared to other nonspecific uptake sites in the subjects, and its tumor-to-normal tissue ratio (TNR) outperformed ICG. Successful resection of in situ hepatocarcinoma and peritoneal carcinoma was achieved using probe imaging guidance, with the smallest visual lesion resected measuring approximately 1 mm3. Ultimately, this probe holds great potential for advancing tumor tracer.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Surgery, Computer-Assisted , Humans , Fluorescent Dyes , Optical Imaging/methods , Surgery, Computer-Assisted/methods
2.
Circulation ; 149(8): 605-626, 2024 02 20.
Article in English | MEDLINE | ID: mdl-38018454

ABSTRACT

BACKGROUND: A better understanding of the molecular mechanism of aortic valve development and bicuspid aortic valve (BAV) formation would significantly improve and optimize the therapeutic strategy for BAV treatment. Over the past decade, the genes involved in aortic valve development and BAV formation have been increasingly recognized. On the other hand, ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) gene family members have been reported to be able to modulate cardiovascular development and diseases. The present study aimed to further investigate the roles of ADAMTS family members in aortic valve development and BAV formation. METHODS: Morpholino-based ADAMTS family gene-targeted screening for zebrafish heart outflow tract phenotypes combined with DNA sequencing in a 304 cohort BAV patient registry study was initially carried out to identify potentially related genes. Both ADAMTS gene-specific fluorescence in situ hybridization assay and genetic tracing experiments were performed to evaluate the expression pattern in the aortic valve. Accordingly, related genetic mouse models (both knockout and knockin) were generated using the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9) method to further study the roles of ADAMTS family genes. The lineage-tracing technique was used again to evaluate how the cellular activity of specific progenitor cells was regulated by ADAMTS genes. Bulk RNA sequencing was used to investigate the signaling pathways involved. Inducible pluripotent stem cells derived from both BAV patients and genetic mouse tissue were used to study the molecular mechanism of ADAMTS. Immunohistochemistry was performed to examine the phenotype of cardiac valve anomalies, especially in the extracellular matrix components. RESULTS: ADAMTS genes targeting and phenotype screening in zebrafish and targeted DNA sequencing on a cohort of patients with BAV identified ADAMTS16 (a disintegrin and metalloproteinase with thrombospondin motifs 16) as a BAV-causing gene and found the ADAMTS16 p. H357Q variant in an inherited BAV family. Both in situ hybridization and genetic tracing studies described a unique spatiotemporal pattern of ADAMTS16 expression during aortic valve development. Adamts16+/- and Adamts16+/H355Q mouse models both exhibited a right coronary cusp-noncoronary cusp fusion-type BAV phenotype, with progressive aortic valve thickening associated with raphe formation (fusion of the commissure). Further, ADAMTS16 deficiency in Tie2 lineage cells recapitulated the BAV phenotype. This was confirmed in lineage-tracing mouse models in which Adamts16 deficiency affected endothelial and second heart field cells, not the neural crest cells. Accordingly, the changes were mainly detected in the noncoronary and right coronary leaflets. Bulk RNA sequencing using inducible pluripotent stem cells-derived endothelial cells and genetic mouse embryonic heart tissue unveiled enhanced FAK (focal adhesion kinase) signaling, which was accompanied by elevated fibronectin levels. Both in vitro inducible pluripotent stem cells-derived endothelial cells culture and ex vivo embryonic outflow tract explant studies validated the altered FAK signaling. CONCLUSIONS: Our present study identified a novel BAV-causing ADAMTS16 p. H357Q variant. ADAMTS16 deficiency led to BAV formation.


Subject(s)
Bicuspid Aortic Valve Disease , Heart Defects, Congenital , Heart Valve Diseases , Humans , Animals , Mice , Zebrafish/genetics , Heart Valve Diseases/metabolism , Endothelial Cells/metabolism , Disintegrins/genetics , Disintegrins/metabolism , In Situ Hybridization, Fluorescence , Aortic Valve/metabolism , Heart Defects, Congenital/complications , Extracellular Matrix/metabolism , Thrombospondins/metabolism , Metalloproteases/metabolism , ADAMTS Proteins/genetics , ADAMTS Proteins/metabolism
4.
Nat Commun ; 14(1): 7620, 2023 Nov 22.
Article in English | MEDLINE | ID: mdl-37993467

ABSTRACT

Hydroxycarboxylic acids are crucial metabolic intermediates involved in various physiological and pathological processes, some of which are recognized by specific hydroxycarboxylic acid receptors (HCARs). HCAR2 is one such receptor, activated by endogenous ß-hydroxybutyrate (3-HB) and butyrate, and is the target for Niacin. Interest in HCAR2 has been driven by its potential as a therapeutic target in cardiovascular and neuroinflammatory diseases. However, the limited understanding of how ligands bind to this receptor has hindered the development of alternative drugs able to avoid the common flushing side-effects associated with Niacin therapy. Here, we present three high-resolution structures of HCAR2-Gi1 complexes bound to four different ligands, one potent synthetic agonist (MK-6892) bound alone, and the two structures bound to the allosteric agonist compound 9n in conjunction with either the endogenous ligand 3-HB or niacin. These structures coupled with our functional and computational analyses further our understanding of ligand recognition, allosteric modulation, and activation of HCAR2 and pave the way for the development of high-efficiency drugs with reduced side-effects.


Subject(s)
Niacin , Receptors, G-Protein-Coupled , Humans , Receptors, G-Protein-Coupled/metabolism , Niacin/pharmacology , Ligands , Signal Transduction , Allosteric Regulation , Allosteric Site
5.
Nat Biotechnol ; 2023 Nov 06.
Article in English | MEDLINE | ID: mdl-37932420

ABSTRACT

The development of liver-based adeno-associated virus (AAV) gene therapies is facing concerns about limited efficiency and durability of transgene expression. We evaluated nonhuman primates following intravenous dosing of AAV8 and AAVrh10 vectors for over 2 years to better define the mechanism(s) of transduction that affect performance. High transduction of non-immunogenic transgenes was achieved, although expression declined over the first 90 days to reach a lower but stable steady state. More than 10% of hepatocytes contained single nuclear domains of vector DNA that persisted despite the loss of transgene expression. Greater reductions in vector DNA and RNA were observed with immunogenic transgenes. Genomic integration of vector sequences, including complex concatemeric structures, were detected in 1 out of 100 cells at broadly distributed loci that were not in proximity to genes associated with hepatocellular carcinoma. Our studies suggest that AAV-mediated transgene expression in primate hepatocytes occurs in two phases: high but short-lived expression from episomal genomes, followed by much lower but stable expression, likely from integrated vectors.

7.
Nature ; 622(7984): 802-809, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37853123

ABSTRACT

Ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist1, has revolutionized the treatment of depression because of its potent, rapid and sustained antidepressant effects2-4. Although the elimination half-life of ketamine is only 13 min in mice5, its antidepressant activities can last for at least 24 h6-9. This large discrepancy poses an interesting basic biological question and has strong clinical implications. Here we demonstrate that after a single systemic injection, ketamine continues to suppress burst firing and block NMDARs in the lateral habenula (LHb) for up to 24 h. This long inhibition of NMDARs is not due to endocytosis but depends on the use-dependent trapping of ketamine in NMDARs. The rate of untrapping is regulated by neural activity. Harnessing the dynamic equilibrium of ketamine-NMDAR interactions by activating the LHb and opening local NMDARs at different plasma ketamine concentrations, we were able to either shorten or prolong the antidepressant effects of ketamine in vivo. These results provide new insights into the causal mechanisms of the sustained antidepressant effects of ketamine. The ability to modulate the duration of ketamine action based on the biophysical properties of ketamine-NMDAR interactions opens up new opportunities for the therapeutic use of ketamine.


Subject(s)
Antidepressive Agents , Depression , Habenula , Ketamine , Receptors, N-Methyl-D-Aspartate , Animals , Mice , Antidepressive Agents/administration & dosage , Antidepressive Agents/metabolism , Antidepressive Agents/pharmacokinetics , Antidepressive Agents/pharmacology , Depression/drug therapy , Depression/metabolism , Habenula/drug effects , Habenula/metabolism , Half-Life , Ketamine/administration & dosage , Ketamine/metabolism , Ketamine/pharmacokinetics , Ketamine/pharmacology , Neurons/physiology , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Receptors, N-Methyl-D-Aspartate/metabolism , Time Factors , Protein Binding
8.
PLoS One ; 18(4): e0284730, 2023.
Article in English | MEDLINE | ID: mdl-37098081

ABSTRACT

To determine the relevance of morphometric properties attributed to the meat yield and fatness index of the saltwater hard clam Meretrix meretrix. A new strain of M. meretrix with red shell color was produced after five generations of selection within a family of full-sibs. 7 morphometric traits, including shell length (SL), shell height (SH), shell width (SW), ligament length (LL), projection length (PL), projection width (PW), and live body weight (LW), and 2 meat characteristics, including meat yield (MY) and fatness index (FI) were measured from 50 individuals of three-year-old M. meretrix. The correlation coefficients, path coefficients, determination coefficients among attributes were analyzed. The results indicated that correlation achieved very significant levels (P<0.01). In addition, the multiple regression equations were formulated by considering the meat yield and fatness index as the dependent variables, respectively, and 7 other morphometric traits as independent variables. The correlation indices (R2) of morphometric traits against the meat yield and fatness index of clams were 0.901 and 0,929, respectively, indicating that the live body weight and shell length were the common main factors influencing the meat characteristics. By testing the significance of partial regression coefficient and gradually removing the non-significant morphometric traits, a multiple regression equation was established to estimate the relationship between shell length (SL, mm), live body weight (LW, g), ligament length (LL, mm) and meat yield (MY, %), fat index (FI, %): MY (%) = 0.432SL+0.251LW and FI (%) = 0.156SL+0.067LL+0.42LW-3.533. The study draws a conclusion that live body weight and shell length have a predominant direct effect on the meat yield and fatness index, which provides theoretical information for the breeding of M. meretrix.


Subject(s)
Bivalvia , Meat , Humans , Child, Preschool , Animals , Seafood , Phenotype , Body Weight
9.
Int J Ment Health Addict ; : 1-23, 2023 Feb 10.
Article in English | MEDLINE | ID: mdl-36817983

ABSTRACT

Cannabis is the fourth psychoactive substance to be legalized which are of far-reaching significance to the world. We analyzed data from the 2019 Global Burden of Disease Study (GBD) to estimate the incidence and prevalence of cannabis use disorder (CUD) and calculated the disease burden of CUD in 204 countries and territories and 21 regions over the past three decades. We reported disease burden due to CUD in terms of disability-adjusted life years (DALYs), age-standardized rate (ASR), estimated annual percentage change (EAPC), and analyzed associations between the burden of CUD and sociodemographic index (SDI) quintiles. Globally, the number of incidence cases of CUD was estimated to be increasing by 32.3% from 1990 to 2019 and males are nearly double higher than that of female. DALYs increase 38.6% from 1990. Young people aged 20-24 years old with cannabis use disorder have the highest DALYs in 2019, followed by those younger than 20 years old. India, Canada, USA, Qatar, Kenya, and high SDI quintile areas showed a high burden of disease. Nearly 200 million individuals are cannabis users worldwide, and CUD is a notable condition of GBD. The global cultivation of cannabis, rooted in different cultures, diversified access to cannabis, legalization in controversy, the promotion of medical cannabis, and many other factors promote the global cannabis industry is constantly updated and upgraded. It deserves more discussion in the future in terms of pathophysiological mechanisms, socioeconomics, law, and policy improvement. Supplementary Information: The online version contains supplementary material available at 10.1007/s11469-022-00999-4.

10.
Int Immunopharmacol ; 114: 109484, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36450207

ABSTRACT

Rheumatoid arthritis (RA) is a systemic autoimmune inflammatory disorder affecting primarily the joints. Neutrophils and the release of neutrophil extracellular traps (NETs) contribute to the pathogenesis of RA. However, IgD, which was abnormally higher in RA, has not been studied for its pathological role in neutrophil activation and NETs formation. To investigate the effects of IgD on neutrophil activation and NETs formation via IgD receptor (FcδR), we collect peripheral blood of RA patients and established adjuvant-induced arthritis (AA) rat model. We found that the expression of FcδR on neutrophils was significantly higher in RA patients compared with healthy controls. As a specific marker of NETs, the level of citrullinated histone H3 was positively correlated with sIgD and FcδR in RA patients. IgD enhances the release of NETs and promotes the proliferation of fibroblast-like synoviocytes (FLS) from RA patients by activating neutrophils. As a competitive FcδR blocker, IgD-Fc-Ig fusion protein could significantly reduce NETs formation and FcδR expression on neutrophils in vitro. In vivo, IgD-Fc-Ig could restrain IgD-induced neutrophil activation and NETs formation, thus inhibited FLS proliferation in AA rats. Data presented here demonstrate that neutrophils could be triggered by IgD to release NETs and take part in FLS proliferation in RA patients with excessive IgD. Blocking IgD-FcδR could inhibit neutrophil activation and NETs formation, and represent an additional attractive novel therapeutic strategy for the treatment of RA.


Subject(s)
Arthritis, Rheumatoid , Extracellular Traps , Synoviocytes , Rats , Animals , Neutrophils , Histones/metabolism , Synoviocytes/metabolism
11.
Hum Gene Ther ; 33(21-22): 1174-1186, 2022 11.
Article in English | MEDLINE | ID: mdl-36375122

ABSTRACT

Transthyretin amyloidosis (ATTR) is a progressive and fatal disease caused by transthyretin (TTR) amyloid fibril accumulation in tissues, which disrupts organ function. As the TTR protein is primarily synthesized by the liver, liver transplantation can cure familial ATTR but is not an option for the predominant age-related wild-type ATTR. Approved treatment approaches include TTR stabilizers and an RNA-interference therapeutic, but these require regular re-administration. Gene editing could represent an effective one-time treatment. We evaluated adeno-associated virus (AAV) vector-delivered, gene-editing meganucleases to reduce TTR levels. We used engineered meganucleases targeting two different sites within the TTR gene. AAV vectors expressing TTR meganuclease transgenes were first tested in immunodeficient mice expressing the human TTR sequence delivered using an AAV vector and then against the endogenous TTR gene in rhesus macaques. Following a dose of 3 × 1013 genome copies per kilogram, we detected on-target editing efficiency of up to 45% insertions and deletions (indels) in the TTR genomic DNA locus and >80% indels in TTR RNA, with a concomitant decrease in serum TTR levels of >95% in macaques. The significant reduction in serum TTR levels following TTR gene editing indicates that this approach could be an effective treatment for ATTR.


Subject(s)
Amyloid Neuropathies, Familial , Dependovirus , Humans , Mice , Animals , Dependovirus/genetics , Dependovirus/metabolism , Macaca mulatta/genetics , Macaca mulatta/metabolism , Amyloid Neuropathies, Familial/therapy , Amyloid Neuropathies, Familial/drug therapy , Prealbumin/genetics , Prealbumin/metabolism , Prealbumin/therapeutic use , RNA/therapeutic use
12.
Phys Rev Lett ; 129(19): 196602, 2022 Nov 04.
Article in English | MEDLINE | ID: mdl-36399761

ABSTRACT

Higher-dimensional topological phases play a key role in understanding the lower-dimensional topological phases and the related topological responses through a dimensional reduction procedure. In this work, we present a Dirac-type model of four-dimensional Z_{2} topological insulator (TI) protected by CP symmetry, whose 3D boundary supports an odd number of Dirac cones. A specific perturbation splits each bulk massive Dirac cone into two valleys separated in energy-momentum space with opposite second Chern numbers, in which the 3D boundary modes become a nodal sphere or a Weyl semimetallic phase. By introducing the electromagnetic (EM) and pseudo-EM fields, exotic topological responses of our 4D system are revealed, which are found to be described by the (4+1)D mixed Chern-Simons theories in the low-energy regime. Notably, several topological phase transitions occur from a CP-broken Z_{2} TI to a Z TI when the bulk gap closes by giving rise to exotic double-nodal-line or nodal-hyper-torus gapless phases. Finally, we propose to probe experimentally these topological effects in cold atoms.

13.
Int J Anal Chem ; 2022: 4996265, 2022.
Article in English | MEDLINE | ID: mdl-35782585

ABSTRACT

In this research article, the molybdenum alloy was prepared by solid-solid doping, selecting pure Mo powder, amorphous Si powder, and B powder as the experimental raw materials for SLM molding. The density and mechanical properties of Mo-Si-B alloys prepared by SLM technology under different processes and compositions were explored, and at the same time, the microstructure of the obtained alloy was observed. The result shows that, with a laser power of 250 W, a scanning speed of 500 mm/s, and a scanning distance of 60 µm, the Mo4.5-Si2-B (at.%) alloy has the highest forming rate under the 120°parameters of the rotating scanning strategy, and the highest density is 94.22%.

14.
Article in English | MEDLINE | ID: mdl-35677384

ABSTRACT

Currently, there are many effective pharmacological treatments for generalized anxiety disorder (GAD), formulated herbal granule is also an alternative way. Our research intends to construct a pharmacological network on genetic targets and pathways between Jiu Wei Zhen Xin Formula (JWZXF) and GAD. Through the TCMSP database, we collected the active ingredients of JWZXF and potential targets of the active ingredients. The GAD-related proteins collected from GeneCards database and DisGeNET database were combined. Component-target protein networks were constructed and visualized using Cytoscape 3.8.2 software to comprehensively clarify the relationships between ingredients, components, and targets. The intersection targets were imported into the STRING database, and the protein-protein interaction (PPI) network was constructed. We constructed and analyzed the visualized "drug-target-disease" network. Gene Ontology (GO) enrichment together with Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis were conducted on the common target through R language. Forty-one effective components and 106 potential targets of JWZXF were found. There were top ten hub genes and multiple important signaling pathways involved in the treatment of GAD with the JWZXF. This study expounded the pharmacological actions and molecular mechanisms of the JWZXF in treating GAD from a holistic perspective. The potential pharmacological effects of the JWZXF are closely related to regulation because not only does it comprehensively analyze the possible mechanism of JWZXF treatment of GAD but it can also facilitate further in-depth research and provide a theoretical basis for the clinical expansion of its application.

15.
iScience ; 25(4): 104042, 2022 Apr 15.
Article in English | MEDLINE | ID: mdl-35330682

ABSTRACT

Extracellular vesicles (EVs) participate in intercellular communication and contribute to the angiogenesis. However, the understanding of the mechanisms underlying EVs secretion by neurons and their action on the vascular system of the central nervous system (CNS) remain rudimentary. Here, we show that vacuolar protein sorting 28 (Vps28) is essential for the sprouting of brain central arteries (CtAs) and for the integrity of blood-brain barrier (BBB) in zebrafish. Disruption of neuron-enriched Vps28 significantly decreased EVs secretion by regulating the formation of intracellular multivesicular bodies (MVBs). EVs derived from zebrafish embryos or mouse cortical neurons partially rescued the brain vasculature defect and brain leakage. Further investigations revealed that neuronal EVs containing vascular endothelial growth factor A (VEGF-A) are key regulators in neurovascular communication. Our results indicate that Vps28 acts as an intercellular endosomal regulator mediating the secretion of neuronal EVs, which in turn communicate with endothelial cells to mediate angiogenesis through VEGF-A trafficking.

16.
J Phys Chem Lett ; 13(12): 2792-2799, 2022 Mar 31.
Article in English | MEDLINE | ID: mdl-35319208

ABSTRACT

Spontaneous enhancement of the photovoltaic performance of perovskite solar cells (PSCs) after aging has been reported, but the underlying reasons for such behavior are still under debate. Herein, we demonstrate that this spontaneous improvement effect accompanied by self-attenuation of hysteresis in the current-voltage characteristics is time- and temperature-dependent. Moreover, it is universal to PSCs based on a range of mixed-ion perovskites and coupled to different hole- and electron-transporting materials. Time-resolved confocal fluorescence microscopy and other characterization techniques suggest that the "self-healing" phenomenon is accompanied by the homogenization and enhancement of the charge extraction efficiency as well as suppressed recombination throughout cm2-scale perovskite layers. These dynamic effects need to be accounted for when assessing the initial and stabilized performance of PSCs.

17.
Science ; 375(6584): 1017-1020, 2022 03 04.
Article in English | MEDLINE | ID: mdl-35239384

ABSTRACT

Magnetic monopoles play a central role in areas of physics that range from electromagnetism to topological matter. String theory promotes conventional vector gauge fields of electrodynamics to tensor gauge fields and predicts the existence of more exotic tensor monopoles. Here, we report the synthesis of a tensor monopole in a four-dimensional parameter space defined by the spin degrees of freedom of a single solid-state defect in diamond. Using two complementary methods, we characterized the tensor monopole by measuring its quantized topological charge and its emanating Kalb-Ramond field. By introducing a fictitious external field that breaks chiral symmetry, we further observed an intriguing spectral transition, characterized by spectral rings protected by mirror symmetries. Our work demonstrates the possibility of emulating exotic topological structures inspired by string theory.

18.
Oxid Med Cell Longev ; 2022: 2265725, 2022.
Article in English | MEDLINE | ID: mdl-35198094

ABSTRACT

Oxidative stress plays a critical role in age-related macular degeneration (AMD), and epithelial-mesenchymal transition (EMT) is involved in this process. The aim of this study was to investigate the protective effects of luteolin, a natural flavonoid with strong antioxidant activity, on H2O2-induced EMT in ARPE-19 cells. ARPE-19 cells were incubated with H2O2 at 200 µΜ to induce oxidative stress-associated injury. Cell viability assay showed that luteolin at 20 and 40 µM significantly promoted cell survival in H2O2-treated ARPE-19 cells. Luteolin also markedly protected ARPE-19 cells from H2O2-induced apoptosis. Cell migration assay presented that luteolin significantly reduced H2O2-induced migration in APRE-19 cells. EMT in ARPE-19 cells was detected by western blotting and immunofluorescence. The results showed that H2O2 significantly upregulated the expression of α-SMA and vimentin and downregulated the expression of ZO-1 and E-cadherin, while cells pretreated with luteolin showed a reversal. Meanwhile, the assessment of effects of luteolin on the Nrf2 pathway indicated that luteolin promoted Nrf2 nuclear translocation and upregulated the expressions of HO-1 and NQO-1. In addition, luteolin significantly increased the activities of SOD and GSH-PX and decreased intracellular levels of ROS and MDA in H2O2-treated ARPE-19 cells. Meanwhile, we observed that the expression of TGF-ß2, p-AKT, and p-GSK-3ß was upregulated in H2O2-treated ARPE-19 cells and downregulated in luteolin-treated cells, revealing that luteolin inhibited the activation of the AKT/GSK-3ß pathway. However, these effects of luteolin were all annulled by transfecting ARPE-19 cells with Nrf2 siRNA. Our current data collectively indicated that inhibition of luteolin on EMT was induced by oxidative injury in ARPE-19 cell through the Nrf2 and AKT/GSK-3ß pathway, suggesting that luteolin could be a potential drug for the treatment of dry AMD.


Subject(s)
Epithelial-Mesenchymal Transition/drug effects , Glycogen Synthase Kinase 3 beta/metabolism , Luteolin/pharmacology , NF-E2-Related Factor 2/metabolism , Oxidative Stress/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Active Transport, Cell Nucleus/drug effects , Antioxidants/metabolism , Cell Line , Cell Movement/drug effects , Cell Nucleus/metabolism , Humans , Hydrogen Peroxide/toxicity , Retinal Pigment Epithelium/cytology , Signal Transduction/drug effects
19.
J Mol Cell Biol ; 13(12): 902-917, 2022 01 29.
Article in English | MEDLINE | ID: mdl-34791311

ABSTRACT

18S, 5.8S, and 28S ribosomal RNAs (rRNAs) are cotranscribed as a pre-ribosomal RNA (pre-rRNA) from the rDNA by RNA polymerase I whose activity is vigorous during the S-phase, leading to a conflict with rDNA replication. This conflict is resolved partly by replication-fork-barrier (RFB)-sites sequences located downstream of the rDNA and RFB-binding proteins such as Ttf1. However, how Ttf1 is displaced from RFB-sites to allow replication fork progression remains elusive. Here, we reported that loss-of-function of Bms1l, a nucleolar GTPase, upregulates rDNA transcription, causes replication-fork stall, and arrests cell cycle at the S-to-G2 transition; however, the G1-to-S transition is constitutively active characterized by persisting DNA synthesis. Concomitantly, ubf, tif-IA, and taf1b marking rDNA transcription, Chk2, Rad51, and p53 marking DNA-damage response, and Rpa2, PCNA, Fen1, and Ttf1 marking replication fork stall are all highly elevated in bms1l mutants. We found that Bms1 interacts with Ttf1 in addition to Rc1l. Finally, we identified RFB-sites for zebrafish Ttf1 through chromatin immunoprecipitation sequencing and showed that Bms1 disassociates the Ttf1‒RFB complex with its GTPase activity. We propose that Bms1 functions to balance rDNA transcription and replication at the S-phase through interaction with Rcl1 and Ttf1, respectively. TTF1 and Bms1 together might impose an S-phase checkpoint at the rDNA loci.


Subject(s)
GTP Phosphohydrolases , Zebrafish , Animals , DNA Replication , DNA, Ribosomal/genetics , GTP Phosphohydrolases/genetics , GTP Phosphohydrolases/metabolism , RNA Polymerase I/metabolism , RNA, Ribosomal/genetics , Zebrafish/genetics
20.
Front Pediatr ; 9: 718704, 2021.
Article in English | MEDLINE | ID: mdl-34513766

ABSTRACT

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common neurological disorder triggered by perinatal cerebral ischemia and hypoxia. Accumulating evidence has shown that peptides have neuroprotective effects in nerve injury. However, the function of endogenous peptides in the pathogenesis of HIE has not been studied. In the present study, a comparative peptidomic profile was performed in the serum of the human umbilical cord blood with HIE (three patients) and the control group (three health control) by liquid chromatography-mass spectrometry (LC-MS). Our study demonstrated that a total of 49 peptides derived from 25 precursor proteins were differentially expressed in the serum of HIE compared with normal controls, including 33 upregulated peptides and 16 downregulated peptides. Each of the differentially expressed peptides has specific characteristics, including pI, Mw, and cleavage pattern. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that the precursor proteins of differentially expressed peptides participate in the different biological process. Moreover, among the 49 differentially expressed peptides, 21 peptides were identified from the fibrinogen chain family, which plays a role in neurological diseases, suggesting that these peptides may play an important role in maintaining brain health. In conclusion, our results showed a comparative peptidomic profile from human umbilical cord blood of HIE patients and normal controls. These dysregulated peptides may have potentially important functions in umbilical cord blood with HIE and may be involved in the pathogenesis of the HIE.

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