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1.
Adv Sci (Weinh) ; : e2403376, 2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39023073

ABSTRACT

Post-replicative DNA N6-methyladenine (pr6mdA) can form via bona fide methylase-catalyzed adenine methylation, playing a pivotal role in embryonic development and other biological processes. Surprisingly, pre-methylated adenine can be erroneously incorporated into DNA as misincorporated N6-methyladenine (i6mdA) via DNA polymerase-mediated replication. Despite pr6mdA and i6mdA sharing identical chemical structures, their biological functions diverge significantly, presenting a substantial challenge in distinguishing between the two. Here, for the first-time, it is exploited that the adenosine deaminase-like (Adal) protein and a corresponding activity-null mutant to construct an Adal lentivirus toolkit. With this newly designed toolkit, both pr6mdA and i6mdA can be identified and quantified simultaneously. The presence of 6mdA in the bone marrow cells of mice is shown, with its levels serving as indicators for growth with age, probably reflecting the cellular stress-caused changes in RNA decay, nucleotide pool sanitation, and transcription. Collectively, a powerful toolkit to advance understanding of both pr6mdA and i6mdA is demonstrated.

2.
Sci Rep ; 14(1): 16830, 2024 07 22.
Article in English | MEDLINE | ID: mdl-39039227

ABSTRACT

Two important factors affecting the progress of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are the S-protein binding function of ACE2 receptors and the membrane fluidity of host cells. This study aimed to evaluate the effect of static magnetic field (SMF) on S-protein/ACE2 binding and cellular membrane fluidity of lung cells, and was performed in vitro using a Calu-3 cell model and in vivo using an animal model. The ability of ACE2 receptors to bind to SARS-CoV-2 spike protein on host cell surfaces under SMF stimulation was evaluated using fluorescence images. Host lung cell membrane fluidity was tested using fluorescence polarization to determine the effects of SMF. Our results indicate that 0.4 T SMF can affect binding between S-protein and ACE2 receptors and increase Calu-3 cell membrane fluidity, and that SMF exposure attenuates LPS-induced alveolar wall thickening in mice. These results may be of value for developing future non-contact, non-invasive, and low side-effect treatments to reduce disease severity in COVID-19-invaded lungs.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Lung , Membrane Fluidity , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Animals , COVID-19/therapy , COVID-19/virology , Angiotensin-Converting Enzyme 2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Lung/pathology , Lung/metabolism , Mice , Humans , Magnetic Fields , Cell Line , Disease Models, Animal , Protein Binding
3.
Virus Res ; 345: 199391, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38754785

ABSTRACT

Coronaviruses (CoVs) are enveloped single-stranded RNA viruses that predominantly attack the human respiratory system. In recent decades, several deadly human CoVs, including SARS-CoV, SARS-CoV-2, and MERS-CoV, have brought great impact on public health and economics. However, their high infectivity and the demand for high biosafety level facilities restrict the pathogenesis research of CoV infection. Exacerbated inflammatory cell infiltration is associated with poor prognosis in CoV-associated diseases. In this study, we used human CoV 229E (HCoV-229E), a CoV associated with relatively fewer biohazards, to investigate the pathogenesis of CoV infection and the regulation of neutrophil functions by CoV-infected lung cells. Induced pluripotent stem cell (iPSC)-derived alveolar epithelial type II cells (iAECIIs) exhibiting specific biomarkers and phenotypes were employed as an experimental model for CoV infection. After infection, the detection of dsRNA, S, and N proteins validated the infection of iAECIIs with HCoV-229E. The culture medium conditioned by the infected iAECIIs promoted the migration of neutrophils as well as their adhesion to the infected iAECIIs. Cytokine array revealed the elevated secretion of cytokines associated with chemotaxis and adhesion into the conditioned media from the infected iAECIIs. The importance of IL-8 secretion and ICAM-1 expression for neutrophil migration and adhesion, respectively, was demonstrated by using neutralizing antibodies. Moreover, next-generation sequencing analysis of the transcriptome revealed the upregulation of genes associated with cytokine signaling. To summarize, we established an in vitro model of CoV infection that can be applied for the study of the immune system perturbations during severe coronaviral disease.


Subject(s)
Alveolar Epithelial Cells , Induced Pluripotent Stem Cells , Neutrophils , Humans , Neutrophils/immunology , Neutrophils/virology , Induced Pluripotent Stem Cells/virology , Alveolar Epithelial Cells/virology , COVID-19/virology , COVID-19/immunology , Intercellular Adhesion Molecule-1/genetics , Intercellular Adhesion Molecule-1/metabolism , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , SARS-CoV-2/immunology , Interleukin-8/genetics , Interleukin-8/metabolism
5.
Article in English | MEDLINE | ID: mdl-38821674

ABSTRACT

Environmental exposure would cause DNA damage and epigenetic modification changes, potentially resulting in physiological dysfunction, thereby triggering diseases and even cancer. DNA damage and epigenetic modifications are thus promising biomarkers for environmental exposures and disease states. Benefiting from its high sensitivity and accuracy, high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) is considered the "gold standard technique" for investigating epigenetic DNA modifications. This review summarizes the recent advancements of UHPLC-MS/MS-based technologies for DNA damage and epigenetic modifications analysis, mainly focusing on the innovative methods developed for UHPLC-MS/MS-related pretreatment technologies containing efficient genomic DNA digestion and effective removal of the inorganic salt matrix, and the new strategies for improving detection sensitivity of liquid chromatography-mass spectrometry. Moreover, we also summarized the novel hyphenated techniques of the advanced UHPLC-MS/MS coupled with other separation and analysis methods for the measurement of DNA damage and epigenetic modification changes in special regions and fragments of chromosomes.


Subject(s)
DNA Damage , Epigenesis, Genetic , Tandem Mass Spectrometry , Tandem Mass Spectrometry/methods , Chromatography, High Pressure Liquid/methods , Humans , DNA Methylation , DNA , Environmental Exposure/analysis , Animals
6.
J Chin Med Assoc ; 87(5): 488-497, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38451105

ABSTRACT

BACKGROUND: Mesenchymal stem cells (MSCs) have promising potential in clinical application, whereas their limited amount and sources hinder their bioavailability. Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have become prominent options in regenerative medicine as both possess the ability to differentiate into MSCs. METHODS: Recently, our research team has successfully developed human leukocyte antigen (HLA)-homozygous iPSC cell lines with high immune compatibility, covering 13.5% of the Taiwanese population. As we deepen our understanding of the differences between these ESCs and HLA-homozygous iPSCs, our study focused on morphological observations and flow cytometry analysis of specific surface marker proteins during the differentiation of ESCs and iPSCs into MSCs. RESULTS: The results showed no significant differences between the two pluripotent stem cells, and both of them demonstrated the equivalent ability to further differentiate into adipose, cartilage, and bone cells. CONCLUSION: Our research revealed that these iPSCs with high immune compatibility exhibit the same differentiation potential as ESCs, enhancing the future applicability of highly immune-compatible iPSCs.


Subject(s)
Cell Differentiation , Embryonic Stem Cells , Induced Pluripotent Stem Cells , Induced Pluripotent Stem Cells/cytology , Humans , Embryonic Stem Cells/cytology , Mesenchymal Stem Cells , Mesoderm/cytology , Cells, Cultured
7.
J Chin Med Assoc ; 87(3): 261-266, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38305450

ABSTRACT

BACKGROUND: Leber hereditary optic neuropathy (LHON) is mainly the degeneration of retinal ganglion cells (RGCs) associated with high apoptosis and reactive oxygen species (ROS) levels, which is accepted to be caused by the mutations in the subunits of complex I of the mitochondrial electron transport chain. The treatment is still infant while efforts of correcting genes or using antioxidants do not bring good and consistent results. Unaffected carrier carries LHON mutation but shows normal phenotype, suggesting that the disease's pathogenesis is complex, in which secondary factors exist and cooperate with the primary complex I dysfunction. METHODS: Using LHON patient-specific induced pluripotent stem cells (iPSCs) as the in vitro disease model, we previously demonstrated that circRNA_0087207 had the most significantly higher expression level in the LHON patient-iPSC-derived RGCs compared with the unaffected carrier-iPSC-derived RGCs. To elaborate the underlying pathologies regulated by circRNA_008720 mechanistically, bioinformatics analysis was conducted and elucidated that circRNA_0087207 could act as a sponge of miR-548c-3p and modulate PLSCR1/TGFB2 levels in ND4 mutation-carrying LHON patient-iPSC-derived RGCs. RESULTS: Using LHON iPSC-derived RGCs as the disease-based platform, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis on targeted mRNA of miR-548c-3p showed the connection with apoptosis, suggesting downregulation of miR548c-3p contributes to the apoptosis of LHON patient RGCs. CONCLUSION: We showed that the downregulation of miR548c-3p plays a critical role in modulating cellular dysfunction and the apoptotic program of RGCs in LHON.


Subject(s)
MicroRNAs , Optic Atrophy, Hereditary, Leber , Humans , Optic Atrophy, Hereditary, Leber/genetics , Optic Atrophy, Hereditary, Leber/pathology , RNA, Circular/genetics , Mitochondria , Apoptosis , Mutation , MicroRNAs/genetics , MicroRNAs/metabolism , Transforming Growth Factor beta2/genetics , Transforming Growth Factor beta2/metabolism
8.
iScience ; 27(2): 108721, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38303704

ABSTRACT

n-3 polyunsaturated fatty acids (PUFAs) are closely related to the progression of numerous chronic inflammatory diseases, but the role of n-3 PUFAs in the intervertebral disc degeneration (IVDD) remains unclear. In this study, male C57BL/6 wildtype mice (WT group, n = 30) and fat-1 transgenic mice (TG group, n = 30) were randomly selected to construct the IVDD model. The results demonstrated that the optimized composition of PUFAs in the TG mice had a significant impact on delaying IVDD and cellular senescence of intervertebral disc (IVD). Mechanismly, n-3 PUFAs inhibited IVD senescence by alleviating NCOA4-mediated iron overload. NCOA4 overexpression promoted iron overload and weakened the pro-proliferation and anti-senescence effect of DHA on the IVD cells. Furthermore, this study futher revealed n-3 PUFAs downregulated NCOA4 expression by inactiviting the LGR5/ß-catenin signaling pathway. This study provides an important theoretical basis for preventing and treating IVDD and low back pain.

9.
J Chin Med Assoc ; 87(3): 267-272, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38277620

ABSTRACT

BACKGROUND: Mesenchymal stem cells (MSCs) have garnered significant attention in the field of cell-based therapy owing to their remarkable capabilities for differentiation and self-renewal. However, primary tissue-derived MSCs are plagued by various limitations, including constrained tissue sources, arduous and invasive retrieval procedures, heterogeneous cell populations, diminished purity, cellular senescence, and a decline in self-renewal and proliferative capacities after extended expansion. Addressing these challenges, our study focuses on establishing a robust differentiation platform to generate mesenchymal stem cells derived from induced pluripotent stem cells (iMSCs). METHODS: To achieve this, we used a comprehensive methodology involving the differentiation of induced pluripotent stem cells into MSCss. The process was meticulously designed to ensure the expression of key MSC positive markers (CD73, CD90, and CD105) at elevated levels, coupled with the minimal expression of negative markers (CD34, CD45, CD11b, CD19, and HLA-DR). Moreover, the stability of these characteristics was evaluated across 10th generations. RESULTS: Our findings attest to the success of this endeavor. iMSCs exhibited robust expression of positive markers and limited expression of negative markers, confirming their MSC identity. Importantly, these characteristics remained stable even up to the 10th generation, signifying the potential for sustained use in therapeutic applications. Furthermore, our study demonstrated the successful differentiation of iMSCs into osteocytes, chondrocytes, and adipocytes, showcasing their multilineage potential. CONCLUSION: In conclusion, the establishment of induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs) presents a significant advancement in overcoming the limitations associated with primary tissue-derived MSCs. The remarkable stability and multilineage differentiation potential exhibited by iMSCs offer a strong foundation for their application in regenerative medicine and tissue engineering. This breakthrough paves the way for further research and development in harnessing the full therapeutic potential of iMSCs.


Subject(s)
Induced Pluripotent Stem Cells , Mesenchymal Stem Cells , Cell Differentiation
10.
Nat Struct Mol Biol ; 31(1): 42-53, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38177668

ABSTRACT

DNA cytosine methylation plays a vital role in repressing retrotransposons, and such derepression is linked with developmental failure, tumorigenesis and aging. DNA methylation patterns are formed by precisely regulated actions of DNA methylation writers (DNA methyltransferases) and erasers (TET, ten-eleven translocation dioxygenases). However, the mechanisms underlying target-specific oxidation of 5mC by TET dioxygenases remain largely unexplored. Here we show that a large low-complexity domain (LCD), located in the catalytic part of Tet enzymes, negatively regulates the dioxygenase activity. Recombinant Tet3 lacking LCD is shown to be hyperactive in converting 5mC into oxidized species in vitro. Endogenous expression of the hyperactive Tet3 mutant in mouse oocytes results in genome-wide 5mC oxidation. Notably, the occurrence of aberrant 5mC oxidation correlates with a consequent loss of the repressive histone mark H3K9me3 at ERVK retrotransposons. The erosion of both 5mC and H3K9me3 causes ERVK derepression along with upregulation of their neighboring genes, potentially leading to the impairment of oocyte development. These findings suggest that Tet dioxygenases use an intrinsic auto-regulatory mechanism to tightly regulate their enzymatic activity, thus achieving spatiotemporal specificity of methylome reprogramming, and highlight the importance of methylome integrity for development.


Subject(s)
5-Methylcytosine , Dioxygenases , Animals , Mice , 5-Methylcytosine/metabolism , Dioxygenases/genetics , Dioxygenases/metabolism , Retroelements/genetics , DNA Methylation , Oocytes/metabolism , Demethylation
11.
J Chin Med Assoc ; 87(1): 12-16, 2024 01 01.
Article in English | MEDLINE | ID: mdl-38016117

ABSTRACT

A maternal inheritance disorder called Leber's hereditary optic neuropathy (LHON) is the most common primary mitochondrial deoxyribonucleic acid (DNA) disorder. In most studies, there are more male patients than female patients, which contradicts the usual pattern in mitochondrial hereditary diseases. This suggests that nuclear DNA (nDNA) may influence the degeneration of retinal ganglion cells (RGCs) in LHON. The primary cause of this is dysfunction in complex I of the electron transport chain, leading to ineffective adenosine triphosphate (ATP) production. In addition to MT-ND4 or MT-ND1 mutations, genes such as PRICKLE3 , YARS2 , and DNAJC30 , which come from nDNA, also play a role in LHON. These three genes affect the electron chain transport differently. PRICKLE3 interacts with ATP synthase (complex V) at Xp11.23, while YARS2 is a tyrosyl-tRNA synthetase 2 involved in mitochondria . DNAJC30 mutations result in autosomal recessive LHON (arLHON). Understanding how genes impact the disease is crucial for developing new treatments. Idebenone has been approved for treating LHON and has shown safety and efficacy in clinical trials. Mesenchymal stem cell-based therapy has also emerged as a potential treatment for LHON by transferring mitochondria into target cells. Gene therapy research focuses on specific gene mutations, and the wild-type ND4 gene target in the adeno-associated viruses (AAV) vector has shown promise in clinical trials as a potential treatment for LHON.


Subject(s)
Optic Atrophy, Hereditary, Leber , Humans , Male , Female , Optic Atrophy, Hereditary, Leber/therapy , Optic Atrophy, Hereditary, Leber/drug therapy , DNA, Mitochondrial/genetics , Mitochondria , Mutation , Adenosine Triphosphate/therapeutic use
12.
J Chin Med Assoc ; 87(2): 163-170, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38132887

ABSTRACT

BACKGROUND: The potential of induced pluripotent stem cells (iPSCs) in revolutionizing regenerative medicine cannot be overstated. iPSCs offer a profound opportunity for therapies involving cell replacement, disease modeling, and cell transplantation. However, the widespread application of iPSC cellular therapy faces hurdles, including the imperative to regulate iPSC differentiation rigorously and the inherent genetic disparities among individuals. To address these challenges, the concept of iPSC super donors emerges, holding exceptional genetic attributes and advantageous traits. These super donors serve as a wellspring of standardized, high-quality cell sources, mitigating inter-individual variations and augmenting the efficacy of therapy. METHODS: In pursuit of this goal, our study embarked on the establishment of iPSC cell lines specifically sourced from donors possessing the HLA type (A33:03-B58:01-DRB1*03:01). The reprogramming process was meticulously executed, resulting in the successful generation of iPSC lines from these carefully selected donors. Subsequently, an extensive characterization was conducted to comprehensively understand the features and attributes of these iPSC lines. RESULTS: The outcomes of our research were highly promising. The reprogramming efforts culminated in the generation of iPSC lines from donors with the specified HLA type. These iPSC lines displayed a range of distinctive characteristics that were thoroughly examined and documented. This successful generation of iPSC lines from super donors possessing advantageous genetic traits represents a significant stride towards the realization of their potential in therapeutic applications. CONCLUSION: In summary, our study marks a crucial milestone in the realm of regenerative medicine. The establishment of iPSC lines from super donors with specific HLA types signifies a paradigm shift in addressing challenges related to iPSC cellular therapy. The standardized and high-quality cell sources derived from these super donors hold immense potential for various therapeutic applications. As we move forward, these findings provide a solid foundation for further research and development, ultimately propelling the field of regenerative medicine toward new horizons of efficacy and accessibility.


Subject(s)
Induced Pluripotent Stem Cells , Humans , Cellular Reprogramming , Cell Differentiation , Cell- and Tissue-Based Therapy
13.
Cells ; 12(22)2023 11 13.
Article in English | MEDLINE | ID: mdl-37998352

ABSTRACT

BACKGROUND: Mesenchymal stem cells (MSCs) hold promise for cell-based therapy, yet the sourcing, quality, and invasive methods of MSCs impede their mass production and quality control. Induced pluripotent stem cell (iPSC)-derived MSCs (iMSCs) can be infinitely expanded, providing advantages over conventional MSCs in terms of meeting unmet clinical demands. METHODS: The potential of MSC therapy for Leber's hereditary optic neuropathy (LHON) remains uncertain. In this study, we used HLA-homozygous induced pluripotent stem cells to generate iMSCs using a defined protocol, and we examined their therapeutic potential in rotenone-induced LHON-like models in vitro and in vivo. RESULTS: The iMSCs did not cause any tumorigenic incidence or inflammation-related lesions after intravitreal transplantation, and they remained viable for at least nine days in the mouse recipient's eyes. In addition, iMSCs exhibited significant efficacy in safeguarding retinal ganglion cells (RGCs) from rotenone-induced cytotoxicity in vitro, and they ameliorated CGL+IPL layer thinning and RGC loss in vivo. Optical coherence tomography (OCT) and an electroretinogram demonstrated that iMSCs not only prevented RGC loss and impairments to the retinal architecture, but they also improved retinal electrophysiology performance. CONCLUSION: The generation of iMSCs via the HLA homozygosity of iPSCs offers a compelling avenue for overcoming the current limitations of MSC-based therapies. The results underscore the potential of iMSCs when addressing retinal disorders, and they highlight their clinical significance, offering renewed hope for individuals affected by LHON and other inherited retinal conditions.


Subject(s)
Induced Pluripotent Stem Cells , Mesenchymal Stem Cells , Optic Atrophy, Hereditary, Leber , Mice , Animals , Optic Atrophy, Hereditary, Leber/chemically induced , Optic Atrophy, Hereditary, Leber/therapy , Optic Atrophy, Hereditary, Leber/pathology , Rotenone/toxicity , Induced Pluripotent Stem Cells/pathology , Retinal Ganglion Cells/pathology , Mesenchymal Stem Cells/pathology
14.
EMBO J ; 42(15): e113684, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37366109

ABSTRACT

Intracellular decay of N6 -methyladenine (m6A)-containing RNA potentially induces aberrant N6 -methyl-2'-adenine (6mdA) misincorporation into DNA. Biophysically, misincorporated 6mdA may destabilize the DNA duplex in a manner similar to bona fide methylated 6mdA DNA, thereby affecting DNA replication and transcription. Utilizing heavy stable isotope labeling and ultrasensitive UHPLC-MS/MS assay, we demonstrate that intracellular m6A-RNA decay does not generate free 6mdA species, nor lead to any misincorporated DNA 6mdA in most mammalian cell lines tested, unveiling the existence of a sanitation mechanism that prevents 6mdA misincorporation. Depletion of deaminase ADAL increases the levels of free 6mdA species, concomitant with the presence of DNA-misincorporated 6mdA resulting from intracellular RNA m6A decay, suggesting that ADAL catabolizes 6mdAMP in vivo. Furthermore, we show that the overexpression of adenylate kinase 1 (AK1) promotes 6mdA misincorporation, while AK1 knockdown diminishes 6mdA incorporation, in ADAL-deficient cells. We conclude that ADAL together with other factors (such as MTH1) contributes to 2'-deoxynucleotide pool sanitation in most cells but compromised sanitation (e.g., in NIH3T3 cells) and increased AK1 expression may facilitate aberrant 6mdA incorporation. This sanitation mechanism may provide a framework for the maintenance of the epigenetic 6mdA landscape.


Subject(s)
Sanitation , Tandem Mass Spectrometry , Animals , Mice , NIH 3T3 Cells , DNA , Adenylate Kinase/genetics , RNA , Mammals
15.
Anal Chem ; 95(18): 7071-7075, 2023 05 09.
Article in English | MEDLINE | ID: mdl-37098799

ABSTRACT

N6-Methyladenine (m6A/6mA) is a functional epigenetic base modification found in RNA and DNA. By selecting one RNA m6A reader as a template, we created a series of libraries of 3 × 108 RNA m6A reader mutants and developed a yeast surface-display-based evolution approach. Using high-throughput fluorescence-activated cell sorting, we ultimately obtained three evolved 6mA-binding proteins (e6mABPs), which displayed increased affinity for 6mA-containing DNA and reduced affinity for 6mA-free DNA. These e6mABPs are applicable for m6A/6mA enrichment and are potentially applied for modulating cell behavior.


Subject(s)
DNA , RNA , RNA/genetics , RNA/metabolism , DNA/genetics , DNA/metabolism , DNA Replication , Adenine/metabolism , DNA Methylation
16.
Cell Rep Med ; 4(2): 100912, 2023 02 21.
Article in English | MEDLINE | ID: mdl-36669488

ABSTRACT

Medical artificial intelligence (AI) has been moving from the research phase to clinical implementation. However, most AI-based models are mainly built using high-quality images preprocessed in the laboratory, which is not representative of real-world settings. This dataset bias proves a major driver of AI system dysfunction. Inspired by the design of flow cytometry, DeepFundus, a deep-learning-based fundus image classifier, is developed to provide automated and multidimensional image sorting to address this data quality gap. DeepFundus achieves areas under the receiver operating characteristic curves (AUCs) over 0.9 in image classification concerning overall quality, clinical quality factors, and structural quality analysis on both the internal test and national validation datasets. Additionally, DeepFundus can be integrated into both model development and clinical application of AI diagnostics to significantly enhance model performance for detecting multiple retinopathies. DeepFundus can be used to construct a data-driven paradigm for improving the entire life cycle of medical AI practice.


Subject(s)
Artificial Intelligence , Flow Cytometry , ROC Curve , Area Under Curve
17.
Curr Opin Chem Biol ; 73: 102259, 2023 04.
Article in English | MEDLINE | ID: mdl-36652775

ABSTRACT

DNA N6-methyladenine modification (6mA) is a predominant epigenetic mark in prokaryotes but rarely present in multicellular metazoa. The analytical technologies have been developed for sensitive detection of 6mA, including ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS/MS) and single molecule real-time sequencing (SMRTseq). However, it remains challenging to detect 6mA at global level and/or in the context of sequence in multicellular metazoa (including mammals). This mini-review brings insights into current dilemma and potential solutions for the identification and quantifications of 6mA in mammals.


Subject(s)
DNA , Tandem Mass Spectrometry , Animals , DNA/chemistry , DNA Methylation , Mammals/genetics
18.
J Chin Med Assoc ; 86(4): 426-430, 2023 04 01.
Article in English | MEDLINE | ID: mdl-36661280

ABSTRACT

BACKGROUND: The volar locking plates have been widely used in a variety of distal radius fractures, but they still have several limitations when dealing with small fragments located around the watershed line with widely reported complications. The volar rim fragments play a critical role in radiocarpal joint stability and failing to secure the volar rim fragment usually results in carpal instability, subluxation, or even dislocation. This study investigates clinical outcomes in the use of a novel implant, the Trident distal radial (TDR) locking plate to treat distal radius fracture with the intermedium column edge (lunate fossa volar rim) fragment involvement. METHODS: A retrospective study of 25 patients was conducted, all patients had intermedium column fractures with lunate fossa volar rim involvement and treat with the TDR between January 2016 and December 2019. The clinical assessment outcomes included VAS Pain, PRWE, and DASH scores. Objective measurements included ROM of the injured wrist and grip strength. Final radiographs were used to evaluate radial inclination, volar tilt, ulnar variance, and distal radioulnar joint instability. Secondary operations related to hardware complications were also recorded. RESULTS: The outcome revealed that the mean VAS Pain Score was 1.3, mean DASH score was 10.5, and mean PRWE score was 9.3. Objective measurements revealed good ROM recovery and an 89% gripping strength recovery compared with contralateral hand. Radiographic measurements revealed good maintenance of volar tilt, radial inclination, and mean ulnar variance. There were no complications related to the implant and all fracture sites were union. CONCLUSION: We believe that the TDR provided more stable fixation among distal radial fractures that predominantly involved the intermedial column and volar rim fragment, and allowing early rehabilitation. We could obtain excellent results in the wrist ROM, gripping power, and Pain Score (VAS).


Subject(s)
Radius Fractures , Wrist Fractures , Humans , Radius/surgery , Radius Fractures/surgery , Retrospective Studies , Fracture Fixation, Internal/methods , Bone Plates , Pain , Range of Motion, Articular , Treatment Outcome
19.
Br J Ophthalmol ; 107(1): 109-115, 2023 01.
Article in English | MEDLINE | ID: mdl-34348922

ABSTRACT

AIMS: To develop a deep learning (DL) model for automatic classification of macular hole (MH) aetiology (idiopathic or secondary), and a multimodal deep fusion network (MDFN) model for reliable prediction of MH status (closed or open) at 1 month after vitrectomy and internal limiting membrane peeling (VILMP). METHODS: In this multicentre retrospective cohort study, a total of 330 MH eyes with 1082 optical coherence tomography (OCT) images and 3300 clinical data enrolled from four ophthalmic centres were used to train, validate and externally test the DL and MDFN models. 266 eyes from three centres were randomly split by eye-level into a training set (80%) and a validation set (20%). In the external testing dataset, 64 eyes were included from the remaining centre. All eyes underwent macular OCT scanning at baseline and 1 month after VILMP. The area under the receiver operated characteristic curve (AUC), accuracy, specificity and sensitivity were used to evaluate the performance of the models. RESULTS: In the external testing set, the AUC, accuracy, specificity and sensitivity of the MH aetiology classification model were 0.965, 0.950, 0.870 and 0.938, respectively; the AUC, accuracy, specificity and sensitivity of the postoperative MH status prediction model were 0.904, 0.825, 0.977 and 0.766, respectively; the AUC, accuracy, specificity and sensitivity of the postoperative idiopathic MH status prediction model were 0.947, 0.875, 0.815 and 0.979, respectively. CONCLUSION: Our DL-based models can accurately classify the MH aetiology and predict the MH status after VILMP. These models would help ophthalmologists in diagnosis and surgical planning of MH.


Subject(s)
Deep Learning , Retinal Perforations , Humans , Retinal Perforations/diagnosis , Retinal Perforations/etiology , Retinal Perforations/surgery , Retrospective Studies , Visual Acuity , Vitrectomy/methods , Tomography, Optical Coherence/methods
20.
J Nanobiotechnology ; 20(1): 511, 2022 Dec 03.
Article in English | MEDLINE | ID: mdl-36463195

ABSTRACT

Inherited Retinal Diseases (IRDs) are considered one of the leading causes of blindness worldwide. However, the majority of them still lack a safe and effective treatment due to their complexity and genetic heterogeneity. Recently, gene therapy is gaining importance as an efficient strategy to address IRDs which were previously considered incurable. The development of the clustered regularly-interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has strongly empowered the field of gene therapy. However, successful gene modifications rely on the efficient delivery of CRISPR-Cas9 components into the complex three-dimensional (3D) architecture of the human retinal tissue. Intriguing findings in the field of nanoparticles (NPs) meet all the criteria required for CRISPR-Cas9 delivery and have made a great contribution toward its therapeutic applications. In addition, exploiting induced pluripotent stem cell (iPSC) technology and in vitro 3D retinal organoids paved the way for prospective clinical trials of the CRISPR-Cas9 system in treating IRDs. This review highlights important advances in NP-based gene therapy, the CRISPR-Cas9 system, and iPSC-derived retinal organoids with a focus on IRDs. Collectively, these studies establish a multidisciplinary approach by integrating nanomedicine and stem cell technologies and demonstrate the utility of retina organoids in developing effective therapies for IRDs.


Subject(s)
Nanoparticles , Retinal Diseases , Humans , CRISPR-Cas Systems/genetics , Prospective Studies , Retinal Diseases/genetics , Retinal Diseases/therapy , Retina , Genetic Therapy
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