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1.
Am J Gastroenterol ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38534155

RESUMO

INTRODUCTION: The prospective study aimed to investigate the long-term associated risks of cirrhosis and hepatocellular carcinoma (HCC) across various subtypes of steatotic liver disease (SLD). METHODS: We enrolled 332,175 adults who participated in a health screening program between 1997 and 2013. Participants were categorized into various subtypes, including metabolic dysfunction-associated SLD (MASLD), MASLD with excessive alcohol consumption (MetALD), and alcohol-related liver disease (ALD), based on ultrasonography findings, alcohol consumption patterns, and cardiometabolic risk factors. We used computerized data linkage with nationwide registries from 1997 to 2019 to ascertain the incidence of cirrhosis and HCC. RESULTS: After a median follow-up of 16 years, 4,458 cases of cirrhosis and 1,392 cases of HCC occurred in the entire cohort, resulting in an incidence rate of 86.1 and 26.8 per 100,000 person-years, respectively. The ALD group exhibited the highest incidence rate for cirrhosis and HCC, followed by MetALD, MASLD, and non-SLD groups. The multivariate adjusted hazard ratios for HCC were 1.92 (95% confidence interval [CI] 1.51-2.44), 2.91 (95% CI 2.11-4.03), and 2.59 (95% CI 1.93-3.48) for MASLD, MetALD, and ALD, respectively, when compared with non-SLD without cardiometabolic risk factors. The pattern of the associated risk of cirrhosis was similar to that of HCC (all P value <0.001). The associated risk of cirrhosis for ALD increased to 4.74 (95% CI 4.08-5.52) when using non-SLD without cardiometabolic risk factors as a reference. DISCUSSION: This study highlights elevated risks of cirrhosis and HCC across various subtypes of SLD compared with non-SLD, emphasizing the importance of behavioral modifications for early prevention.

2.
Acta Neuropathol ; 147(1): 13, 2024 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-38194050

RESUMO

The development of the cerebral cortex involves a series of dynamic events, including cell proliferation and migration, which rely on the motor protein dynein and its regulators NDE1 and NDEL1. While the loss of function in NDE1 leads to microcephaly-related malformations of cortical development (MCDs), NDEL1 variants have not been detected in MCD patients. Here, we identified two patients with pachygyria, with or without subcortical band heterotopia (SBH), carrying the same de novo somatic mosaic NDEL1 variant, p.Arg105Pro (p.R105P). Through single-cell RNA sequencing and spatial transcriptomic analysis, we observed complementary expression of Nde1/NDE1 and Ndel1/NDEL1 in neural progenitors and post-mitotic neurons, respectively. Ndel1 knockdown by in utero electroporation resulted in impaired neuronal migration, a phenotype that could not be rescued by p.R105P. Remarkably, p.R105P expression alone strongly disrupted neuronal migration, increased the length of the leading process, and impaired nucleus-centrosome coupling, suggesting a failure in nucleokinesis. Mechanistically, p.R105P disrupted NDEL1 binding to the dynein regulator LIS1. This study identifies the first lissencephaly-associated NDEL1 variant and sheds light on the distinct roles of NDE1 and NDEL1 in nucleokinesis and MCD pathogenesis.


Assuntos
Lisencefalia , Humanos , Lisencefalia/genética , Movimento Celular/genética , Proliferação de Células , Córtex Cerebral , Dineínas/genética , Proteínas de Transporte , Proteínas Associadas aos Microtúbulos/genética
3.
Artigo em Inglês | MEDLINE | ID: mdl-38725327

RESUMO

BACKGROUND AND AIM: This study estimated the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) according to cardiometabolic risk factors. The long-term impacts of MASLD on all-cause and cardiometabolic-specific mortality were evaluated. METHODS: We enrolled 343 816 adults aged ≥30 years who participated in a health screening program from 1997 through 2013. MASLD was identified on the basis of abdominal ultrasonography and metabolic profiles. The participants were further categorized by liver enzyme elevation. Baseline cardiometabolic comorbidities were classified on the basis of self-reported medication use and clinical seromarkers. All-cause and cardiometabolic-specific deaths were determined through computerized data linkage with nationwide death certifications until December 31, 2020. RESULTS: The overall prevalence of MASLD was 36.4%. Among patients with MASLD, 35.9% had abnormal liver enzyme levels. Compared with patients without MASLD, abnormal liver enzymes were positively associated with cardiometabolic comorbidities in patients with MASLD (Pfor trend < 0.001). After follow-up, patients with MASLD had a 9%-29% higher risk of all-cause, cardiovascular-related, or diabetes-related mortality. In the groups with MASLD and elevated and normal liver enzyme levels, the multivariate-adjusted hazard ratios for cardiovascular deaths were 1.14 (1.05-1.25) and 1.10 (1.03-1.17), respectively, and those for diabetes deaths were 1.42 (1.05-1.93) and 1.24 (0.98-1.57), respectively, compared with those in the non-MASLD group (Pfor trend < 0.001). DISCUSSION: Individuals with MASLD and elevated liver enzyme levels exhibited significantly higher risks of all-cause and cardiometabolic deaths and should be monitored and given consultation on cardiometabolic modifications.

4.
Neuropathol Appl Neurobiol ; 49(2): e12890, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36765387

RESUMO

AIMS: Muscleblind-like 2 (MBNL2) plays a crucial role in regulating alternative splicing during development and mouse loss of MBNL2 recapitulates brain phenotypes in myotonic dystrophy (DM). However, the mechanisms underlying DM neuropathogenesis during brain development remain unclear. In this study, we aim to investigate the impact of MBNL2 elimination on neuronal development by Mbnl2 conditional knockout (CKO) mouse models. METHODS: To create Mbnl2 knockout neurons, cDNA encoding Cre-recombinase was delivered into neural progenitors of Mbnl2flox/flox mouse brains by in utero electroporation. The morphologies and dynamics of dendritic spines were monitored by confocal and two-photon microscopy in brain slices and live animals from the neonatal period into adulthood. To investigate the underlying molecular mechanism, we further detected the changes in the splicing and molecular interactions of proteins associated with spinogenesis. RESULTS: We found that Mbnl2 knockout in cortical neurons decreased dendritic spine density and dynamics in adolescent mice. Mbnl2 ablation caused the adducin 1 (ADD1) isoform to switch from adult to fetal with a frameshift, and the truncated ADD1 failed to interact with alpha-II spectrin (SPTAN1), a critical protein for spinogenesis. In addition, expression of ADD1 adult isoform compensated for the reduced dendritic spine density in cortical neurons deprived of MBNL2. CONCLUSION: MBNL2 plays a critical role in maintaining the dynamics and homeostasis of dendritic spines in the developing brain. Mis-splicing of downstream ADD1 may account for the alterations and contribute to the DM brain pathogenesis.


Assuntos
Espinhas Dendríticas , Distrofia Miotônica , Animais , Camundongos , Encéfalo/patologia , Espinhas Dendríticas/metabolismo , Espinhas Dendríticas/patologia , Distrofia Miotônica/genética , Isoformas de Proteínas/metabolismo
5.
Alzheimers Dement ; 19(11): 4872-4885, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37037474

RESUMO

INTRODUCTION: Sporadic Alzheimer's disease (sAD) is the leading type of dementia. Brain glucose hypometabolism, along with decreased O-GlcNAcylation levels, occurs before the onset of symptoms and correlates with pathogenesis. Heretofore, the mechanisms involved and the roles of O-GlcNAcylation in sAD pathology largely remain unknown due to a lack of human models of sAD. METHODS: Human cortical neurons were generated from pluripotent stem cells (PSCs) and treated with glucose reduction media. RESULTS: We found a narrow window of glucose concentration that induces sAD-like phenotypes in PSC-derived neurons. With our model, we reveal that dysregulated O-GlcNAc, in part through mitochondrial dysfunction, causes the onset of sAD-like changes. We demonstrate the therapeutic potential of inhibiting O-GlcNAcase in alleviating AD-like biochemical changes. DISCUSSION: Our results suggest that dysregulated O-GlcNAc might be a direct molecular link between hypometabolism and sAD-like alternations. Moreover, this model can be exploited to explore molecular processes and for drug development. HIGHLIGHTS: Lowering glucose to a critical level causes AD-like changes in cortical neurons. Defective neuronal structure and function were also recapitulated in current model. Dysregulated O-GlcNAcylation links impaired glucose metabolism to AD-like changes. Mitochondrial abnormalities correlate with O-GlcNAcylation and precede AD-like phenotype. Our model provides a platform to study sAD as a metabolic disease in human neurons.


Assuntos
Doença de Alzheimer , Células-Tronco Pluripotentes Induzidas , Humanos , Doença de Alzheimer/patologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios/metabolismo , Glucose/metabolismo , Acetilglucosamina/metabolismo
6.
Opt Lett ; 47(3): 561-564, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35103671

RESUMO

We demonstrate a Si/SiO/SiO2-based period-chirped guided mode resonance (GMR) filter to discriminate telecom o-band wavelengths by spatially resolved horizontal movement. Continuously period-chirped silicon gratings were fabricated by using a Lloyd's laser interferometer with a convex mirror. Due to the large waveguide effective index, the GMR filter can be realized with a short grating period, thus enabling a slow grating period transition along the sample position and high optical resolution in wavelength discrimination. Depositing a SiO/SiO2 stack on top of silicon gratings enables a narrowband GMR filter with a linewidth of 1-1.5 nm over a wavelength range of 1260-1360 nm. By using the chirped GMR filter as a dispersive device, the optical spectra of a near-infrared broadband light source are reconstructed. An optimized aspheric mirror is proposed to further improve the linearity of chirped gratings. Such a period-chirped GMR filter is promising for compact on-chip spectroscopy and sensing applications.

7.
Cardiovasc Drugs Ther ; 35(1): 61-71, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32902737

RESUMO

PURPOSE: Little is known about the molecular interactions among inflammatory responses that damage venous endothelial cells (vECs) during venous-to-arterial flow transition in vein graft diseases. Because arterial flow triggers excessive autophagy and inflammation in vECs, this study aimed to investigate the mediator of inflammation and methods to prevent vEC damage. METHODS: Arterial laminar shear stress (ALSS; 12 dynes/cm2) was applied to vECs via in vitro and ex vivo perfusion systems. Inflammation in vECs was measured using inflammatory protein markers, NFκB translocation, cyclooxygenase-2 (COX-2) and COX-2 and NFκB promoter assays. The involvement of microRNA-4488 (miR-4488) was measured and confirmed by altering the specific miR using a miR-4488 mimic or inhibitor. The potential anti-inflammatory drugs and/or nitric oxide (NO) donor L-arginine (L-Arg) to prevent damage to vECs under ALSS was investigated. RESULTS: ALSS triggered reactive oxygen species production, excessive autophagy, COX-2 protein expression, and NFκB translocation during vEC inflammation. Reduction in miR-4488 expression was detected in inflamed vECs treated with LPS, lipopolysaccharide (LPS) TNFα, and ALSS. Transfection of miR-4488 mimic (50 nM) prior to ALSS application inhibited the accumulation of inflammatory proteins as well as the translocation of NFκB. Combined treatment of vECs with COX-2-specific inhibitor (SC-236) and L-Arg alleviated the ALSS-induced inflammatory responses. Protective effects of the combined treatment on vECs against ALSS-induced damage were abolished by the application of miR-4488 inhibitor. CONCLUSION: We showed that ALSS triggered the COX-2/NFκB pathway to induce vEC inflammation with a reduction in miR-4488. Combination of SC-236 and L-Arg prevented ALSS-induced vEC damage, thus, shows high potential for preventing vein graft diseases.


Assuntos
Endotélio Vascular/metabolismo , Mediadores da Inflamação/metabolismo , MicroRNAs/biossíntese , NF-kappa B/metabolismo , Anti-Inflamatórios/farmacologia , Autofagia/efeitos dos fármacos , Ponte de Artéria Coronária/efeitos adversos , Vasos Coronários/fisiopatologia , Ciclo-Oxigenase 2/efeitos dos fármacos , Hemodinâmica , Células Endoteliais da Veia Umbilical Humana , Humanos , Lipopolissacarídeos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Veia Safena/fisiopatologia , Transdução de Sinais , Fator de Necrose Tumoral alfa/biossíntese
8.
Appl Opt ; 60(35): 10873-10877, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-35200849

RESUMO

This work develops a tunable chirped guided-mode resonant (GMR) filter that has a hybrid splay-twist (HST) liquid crystal as a cladding layer. The GMR filter is a color reflector that strongly reflects light at the resonance wavelength, and its chirped grating structure supports tuning of the resonance peak over a wavelength range of over 50 nm. The HST-LC configuration serves as an achromatic polarization rotator that can rotate the axis of polarization of linearly polarized light by providing effective twist angles in the LC layer under an applied voltage. The HST-LC is used to change the direction of the polarization axis of the light that is reflected by the GMR filter; continuous angles of rotation of ∼90∘ are achieved and the linear polarization is retained under applied voltages. The proposed filter enables an ultrabroadband polarization rotation and still maintains a high degree of linear polarization, which allows more degrees of freedom in spectral and polarization controls.

9.
Int J Mol Sci ; 22(21)2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34769330

RESUMO

Giardia lamblia persists in a dormant state with a protective cyst wall for transmission. It is incompletely known how three cyst wall proteins (CWPs) are coordinately synthesized during encystation. Meiotic recombination is required for sexual reproduction in animals, fungi, and plants. It is initiated by formation of double-stranded breaks by a topoisomerase-like Spo11. It has been shown that exchange of genetic material in the fused nuclei occurs during Giardia encystation, suggesting parasexual recombination processes of this protozoan. Giardia possesses an evolutionarily conserved Spo11 with typical domains for cleavage reaction and an upregulated expression pattern during encystation. In this study, we asked whether Spo11 can activate encystation process, like other topoisomerases we previously characterized. We found that Spo11 was capable of binding to both single-stranded and double-stranded DNA in vitro and that it could also bind to the cwp promoters in vivo as accessed in chromatin immunoprecipitation assays. Spo11 interacted with WRKY and MYB2 (named from myeloblastosis), transcription factors that can activate cwp gene expression during encystation. Interestingly, overexpression of Spo11 resulted in increased expression of cwp1-3 and myb2 genes and cyst formation. Mutation of the Tyr residue for the active site or two conserved residues corresponding to key DNA-binding residues for Arabidopsis Spo11 reduced the levels of cwp1-3 and myb2 gene expression and cyst formation. Targeted disruption of spo11 gene with CRISPR/Cas9 system led to a significant decrease in cwp1-3 and myb2 gene expression and cyst number. Our results suggest that Spo11 acts as a positive regulator for Giardia differentiation into cyst.


Assuntos
Diferenciação Celular , Cistos/patologia , Endodesoxirribonucleases/metabolismo , Regulação da Expressão Gênica , Proteínas de Protozoários/metabolismo , Animais , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cistos/genética , Cistos/metabolismo , Endodesoxirribonucleases/genética , Giardia lamblia , Regiões Promotoras Genéticas , Proteínas de Protozoários/genética
10.
Small ; 15(50): e1903363, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31608571

RESUMO

Thin film electrocatalysts allow strong binding and intimate electrical contact with electrodes, rapid mass transfer during reaction, and are generally more durable than powder electrocatalysts, which is particularly beneficial for gas evolution reactions. In this work, using cobalt manganese oxyhydroxide, an oxygen evolution reaction (OER) electrocatalyst that can be grown directly on various electrodes as a model system, it is demonstrated that breaking a continuous film into discontinuous patches can significantly enhance the overall OER performance without sacrificing long-term stability even under elevated electrocatalytic stress. Discontinuous films with higher edge-to-area ratios exhibits reduced overpotentials, increased turnover frequency, and more pronounced current increase after electrochemical conditioning. Operando Raman spectroscopy studies during electrocatalysis reveal that the film edges require lower potential barrier for activation. Introducing discontinuity into thin film electrocatalysis can thus lead to the realization of high performance yet highly robust systems for harsh gas evolution reactions.

11.
Opt Express ; 26(21): 27515-27527, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30469817

RESUMO

In this work we introduce a tunable GMR filter based on continuously period-chirped (ΔP = 130 nm) gratings using a Ta2O5 waveguide layer with graded thickness (ΔT = 36 nm). The structure of the gradient-period grating is defined using a modified Lloyd's mirror interferometer with a convex mirror, and Ta2O5 film used for the gradient is deposited using masked e-beam evaporation. The as-realized chirped GMR filter provides sharp transmission dips at resonant wavelengths with a filter bandwidth of approximately 4.2 nm and 0.78 nm when respectively applied to TE and TM polarized light under normal incidence. Gradually sweeping the chirped GMR filter makes it possible to monotonically sweep through resonant wavelengths from 500 to 700 nm, while maintaining stable filter bandwidth and transmission intensity. The optical spectrum of the incoming light can then be loyally reconstructed accordingly. We successfully demonstrate the spectrum reconstruction of a white light emitting diode and a dual-peak laser beam using the proposed chirped GMR filter as a dispersive device.

12.
Opt Lett ; 42(22): 4768-4771, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29140365

RESUMO

Graphene oxide (GO) ultrathin film can be wafer-scale deposited by spin coating, can be patterned by laser interference lithography and oxygen plasma etching, can be thinned atomically (0.26 nm/min) and oxidized by ozone treatment, and is a relatively transparent and low-refractive-index material compared to pristine graphene. All those unique properties prompt us to realize a low-loss (∼5 dB/cm), high-extinction-ratio (19 dB), and narrowband (0.425 nm) GO/silicon hybrid waveguide Bragg reflector by transferring 7-nm-thick GO gratings (n=1.58) atop a silicon strip waveguide. Unlike a sidewall-corrugated strip waveguide Bragg reflector that generally exhibits distorted corrugation profiles and is sensitive to fabrication errors, the as-realized GO-grating-covered strip waveguide Bragg reflector exhibits a stable reflecting wavelength and controllable reflection bandwidth that can be well predicted by numerical simulations.

14.
Development ; 140(13): 2798-807, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23720043

RESUMO

The exostosin (EXT) genes encode glycosyltransferases required for glycosaminoglycan chain polymerization in the biosynthesis of heparan sulfate proteoglycans (HSPGs). Mutations in the tumor suppressor genes EXT1 and EXT2 disturb HSPG biosynthesis and cause multiple osteochondroma (MO). How EXT1 and EXT2 traffic within the Golgi complex is not clear. Here, we show that Rotini (Rti), the Drosophila GOLPH3, regulates the retrograde trafficking of EXTs. A reduction in Rti shifts the steady-state distribution of EXTs to the trans-Golgi. These accumulated EXTs tend to be degraded and their re-entrance towards the route for polymerizing GAG chains is disengaged. Conversely, EXTs are mislocalized towards the transitional endoplasmic reticulum/cis-Golgi when Rti is overexpressed. Both loss of function and overexpression of rti result in incomplete HSPGs and perturb Hedgehog signaling. Consistent with Drosophila, GOLPH3 modulates the dynamic retention and protein stability of EXT1/2 in mammalian species. Our data demonstrate that GOLPH3 modulates the activities of EXTs, thus implicating a putative role for GOLPH3 in the formation of MO.


Assuntos
Proteínas de Drosophila/metabolismo , Proteoglicanas de Heparan Sulfato/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Animais , Drosophila , Proteínas de Drosophila/genética , Transporte Proteico/genética , Transporte Proteico/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
15.
Opt Express ; 24(10): 10675-81, 2016 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-27409888

RESUMO

We report on the demonstration of a passively Q-switched 1.55 µm fiber laser utilizing a colloidal PbS quantum dot (QD) thin film as a saturable absorber. Colloidal PbS QD films have several features that are advantageous in passively Q-switched fiber laser operation, including a large operation wavelength range, cost-effectiveness, and a low saturable absorption intensity. We conducted thorough material and optical studies to verify the advantages of PbS QDs in Q-switched laser operation and successfully generated 801 nJ pulses with a 24.2 kHz repetition rate. To the best of our knowledge, the developed Q-switched fiber laser is the first based on colloidal PbS QDs.

17.
Methods Mol Biol ; 2831: 81-95, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39134845

RESUMO

During the development of mammalian brains, pyramidal neurons in the cerebral cortex form highly organized six layers with different functions. These neurons undergo developmental processes such as axon extension, dendrite outgrowth, and synapse formation. A proper integration of the neuronal connectivity through dynamic changes of dendritic branches and spines is required for learning and memory. Disruption of these crucial developmental processes is associated with many neurodevelopmental and neurodegenerative disorders. To investigate the complex dendritic architecture, several useful staining tools and genetic methods to label neurons have been well established. Monitoring the dynamics of dendritic spine in a single neuron is still a challenging task. Here, we provide a methodology that combines in vivo two-photon brain imaging and in utero electroporation, which sparsely labels cortical neurons with fluorescent proteins. This protocol may help elucidate the dynamics of microstructure and neural complexity in living rodents under normal and disease conditions.


Assuntos
Neurônios , Animais , Camundongos , Neurônios/citologia , Neurônios/metabolismo , Eletroporação/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Espinhas Dendríticas/metabolismo , Espinhas Dendríticas/ultraestrutura , Células Piramidais/metabolismo , Células Piramidais/citologia , Feminino , Córtex Cerebral/citologia , Dendritos/metabolismo
18.
Cell Stem Cell ; 31(5): 734-753.e8, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38608707

RESUMO

Autonomic parasympathetic neurons (parasymNs) control unconscious body responses, including "rest-and-digest." ParasymN innervation is important for organ development, and parasymN dysfunction is a hallmark of autonomic neuropathy. However, parasymN function and dysfunction in humans are vastly understudied due to the lack of a model system. Human pluripotent stem cell (hPSC)-derived neurons can fill this void as a versatile platform. Here, we developed a differentiation paradigm detailing the derivation of functional human parasymNs from Schwann cell progenitors. We employ these neurons (1) to assess human autonomic nervous system (ANS) development, (2) to model neuropathy in the genetic disorder familial dysautonomia (FD), (3) to show parasymN dysfunction during SARS-CoV-2 infection, (4) to model the autoimmune disease Sjögren's syndrome (SS), and (5) to show that parasymNs innervate white adipocytes (WATs) during development and promote WAT maturation. Our model system could become instrumental for future disease modeling and drug discovery studies, as well as for human developmental studies.


Assuntos
Diferenciação Celular , Disautonomia Familiar , Células-Tronco Pluripotentes , Humanos , Células-Tronco Pluripotentes/citologia , Disautonomia Familiar/patologia , Neurônios , Síndrome de Sjogren/patologia , COVID-19/virologia , COVID-19/patologia , Animais , Sistema Nervoso Parassimpático , Células de Schwann , Camundongos , SARS-CoV-2/fisiologia
19.
Neural Regen Res ; 18(4): 779-783, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36204837

RESUMO

Alzheimer's disease is a neurodegenerative disease that affected over 6.5 million people in the United States in 2021, with this number expected to double in the next 40 years without any sort of treatment. Due to its heterogeneity and complexity, the etiology of Alzheimer's disease, especially sporadic Alzheimer's disease, remains largely unclear. Compelling evidence suggests that brain glucose hypometabolism, preceding Alzheimer's disease hallmarks, is involved in the pathogenesis of Alzheimer's disease. Herein, we discuss the potential causes of reduced glucose uptake and the mechanisms underlying glucose hypometabolism and Alzheimer's disease pathology. Specifically, decreased O-GlcNAcylation levels by glucose deficiency alter mitochondrial functions and together contribute to Alzheimer's disease pathogenesis. One major problem with Alzheimer's disease research is that the disease progresses for several years before the onset of any symptoms, suggesting the critical need for appropriate models to study the molecular changes in the early phase of Alzheimer's disease progression. Therefore, this review also discusses current available sporadic Alzheimer's disease models induced by metabolic abnormalities and provides novel directions for establishing a human neuronal sporadic Alzheimer's disease model that better represents human sporadic Alzheimer's disease as a metabolic disease.

20.
Front Neurosci ; 17: 1137847, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37229433

RESUMO

O-GlcNAcylation is a post-translational modification (PTM) that regulates a wide range of cellular functions and has been associated with multiple metabolic diseases in various organs. The sympathetic nervous system (SNS) is the efferent portion of the autonomic nervous system that regulates metabolism of almost all organs in the body. How much the development and functionality of the SNS are influenced by O-GlcNAcylation, as well as how such regulation could contribute to sympathetic neuron (symN)-related neuropathy in diseased states, remains unknown. Here, we assessed the level of protein O-GlcNAcylation at various stages of symN development, using a human pluripotent stem cell (hPSC)-based symN differentiation paradigm. We found that pharmacological disruption of O-GlcNAcylation impaired both the growth and survival of hPSC-derived symNs. In the high glucose condition that mimics hyperglycemia, hPSC-derived symNs were hyperactive, and their regenerative capacity was impaired, which resembled typical neuronal defects in patients and animal models of diabetes mellitus. Using this model of sympathetic neuropathy, we discovered that O-GlcNAcylation increased in symNs under high glucose, which lead to hyperactivity. Pharmacological inhibition of O-GlcNAcylation rescued high glucose-induced symN hyperactivity and cell stress. This framework provides the first insight into the roles of O-GlcNAcylation in both healthy and diseased human symNs and may be used as a platform for therapeutic studies.

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