Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 873
Filter
1.
Exp Gerontol ; 194: 112514, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38971132

ABSTRACT

Mitochondrial dysfunction is a prominent hallmark of Alzheimer's disease (AD). The transcriptional coactivator PPARγ coactivator 1 (PGC-1a) has been identified as a key regulator of mitochondrial biogenesis and function. However, the precise structure/function relationship between PGC-1a and mitochondrial quality control remains incompletely understood. In this study, we investigated the impact of PGC-1a on AD pathology and its underlying mechanisms with a specific focus on mitochondrial axonal transport. Additionally, we generated two PGC-1α mutants by substituting leucine residues at positions 148 and 149 within the LKKLL motif or at positions 209 and 210 within the LLKYL motif with alanine. Subsequently, we examined the effects of these mutants on mutAPP-induced abnormalities in anterograde and retrograde axonal transport, disrupted mitochondrial distribution, and impaired mitophagy. Mutagenesis studies revealed that the LLKYL motif at amino acid position 209-210 within PGC-1α plays an essential role in its interaction with estrogen-related receptors (ERRα), which is necessary for restoring normal mitochondrial anterograde axonal transport, maintaining proper mitochondrial distribution, and ultimately preventing neuronal apoptosis. Furthermore, it was found that the Leu-rich motif at amino acids 209-210 within PGC-1α is crucial for rescuing mutAPP-induced impairment in mitophagy and loss of membrane potential by restoring normal mitochondrial retrograde axonal transport. Conversely, mutation of residues 148 and 149 in the LKKLL motif does not compromise the effectiveness of PGC-1α. These findings provide valuable insights into the molecular determinants governing specificity of action for PGC-1α involved in regulating mutAPP-induced deficits in mitochondrial axonal trafficking. Moreover, they suggest a potential therapeutic target for addressing Alzheimer's disease.

2.
Int Immunopharmacol ; 138: 112617, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38972213

ABSTRACT

Severe steatosis in donor livers is contraindicated for transplantation due to the high risk of ischemia-reperfusion injury (IRI). Although Ho-1 gene-modified bone marrow mesenchymal stem cells (HO-1/BMMSCs) can mitigate IRI, the role of gut microbiota and metabolites in this protection remains unclear. This study aimed to explore how gut microbiota and metabolites contribute to HO-1/BMMSCs-mediated protection against IRI in severe steatotic livers. Using rat models and cellular models (IAR20 and THLE-2 cells) of steatotic liver IRI, this study revealed that ischemia-reperfusion led to significant liver and intestinal damage, heightened immune responses, impaired liver function, and altered gut microbiota and metabolite profiles in rats with severe steatosis, which were partially reversed by HO-1/BMMSCs transplantation. Integrated microbiome and metabolome analyses identified gut microbial metabolite oleanolic acid as a potential protective agent against IRI. Experimental validation showed that oleanolic acid administration alone alleviated IRI and inhibited ferroptosis in both rat and cellular models. Network pharmacology and molecular docking implicated KEAP1/NRF2 pathway as a potential target of oleanolic acid. Indeed, OA experimentally upregulated NRF2 activity, which underlies its inhibition of ferroptosis and protection against IRI. The gut microbial metabolite OA protects against IRI in severe steatotic liver by promoting NRF2 expression and activity, thereby inhibiting ferroptosis.

3.
J Nat Prod ; 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38976838

ABSTRACT

Heterologous expression of an atr terpenoid gene cluster derived from Streptomyces atratus Gö66 in S. albus J1074 led to the discovery of three novel labdane diterpenoids featuring an unprecedented 6/6/5-fused tricyclic skeleton, designated as atralabdans A-C (1-3), along with a known compound, labdanmycin A. Compounds 1-3 were identified through extensive spectroscopic analysis, including NMR calculations with DP4+ probability analysis, and a comparative assessment of experimental and theoretical electronic circular dichroism (ECD) spectra. A plausible biosynthetic pathway for these compounds was proposed. Compounds 1-3 exhibited inhibitory activity against the human neurotropic coxsackievirus B3 (CVB3); 1 was the most potent, surpassing the positive control ribavirin with a higher therapeutic index.

4.
Sci Rep ; 14(1): 16233, 2024 Jul 14.
Article in English | MEDLINE | ID: mdl-39004658

ABSTRACT

Saline-sodic stress restricts the absorption of zinc by rice, consequently impacting the photosynthesis process of rice plants. In this experiment, Landrace 9 was selected as the test material and the potting method was employed to investigate the influence of ZnO nanoparticles (ZnO NPs) on zinc absorption and chlorophyll fluorescence in rice grown in saline-sodic land. The research findings demonstrate that the application of ZnO NPs proves to be more advantageous for the growth of rice in saline-sodic soil. Notably, the application of ZnO NPs significantly decreases the levels of Na+ and MDA in rice leaves in saline-sodic soil, while increasing the levels of K+ and Zn2+. Additionally, ZnO NPs enhances the content of chloroplast pigments, specific energy flux, quantum yield, and the performance of active PSII reaction center (PIABS) in rice leaves under saline-sodic stress. Furthermore, the relative variable fluorescence (WK and VJ) and quantum energy dissipation rate (φDo) of rice are also reduced. Therefore, the addition of ZnO NPs enhances the transfer of electrons and energy within the rice photosystem when subjected to saline-sodic stress. This promotes photosynthesis in rice plants growing in saline-sodic land, increasing their resistance to saline-sodic stress and ultimately facilitating their growth and development.


Subject(s)
Oryza , Photosynthesis , Plant Leaves , Soil , Zinc Oxide , Oryza/metabolism , Oryza/drug effects , Oryza/growth & development , Zinc Oxide/pharmacology , Photosynthesis/drug effects , Plant Leaves/metabolism , Plant Leaves/drug effects , Soil/chemistry , Chlorophyll/metabolism , Photosystem II Protein Complex/metabolism , Metal Nanoparticles/chemistry , Fluorescence , Salinity
5.
Mol Med Rep ; 30(3)2024 Sep.
Article in English | MEDLINE | ID: mdl-38963030

ABSTRACT

DNA methylation is one of the earliest and most significant epigenetic mechanisms discovered. DNA methylation refers, in general, to the addition of a methyl group to a specific base in the DNA sequence under the catalysis of DNA methyltransferase, with S­adenosine methionine as the methyl donor, via covalent bonding and chemical modifications. DNA methylation is an important factor in inducing cancer. There are different types of DNA methylation, and methylation at different sites plays different roles. It is well known that the progression of colorectal cancer (CRC) is affected by the methylation of key genes. The present review did not only discuss the potential relationship between DNA methylation and CRC but also discussed how DNA methylation affects the development of CRC by affecting key genes. Furthermore, the clinical significance of DNA methylation in CRC was highlighted, including that of the therapeutic targets and biomarkers of methylation; and the importance of DNA methylation inhibitors was discussed as a novel strategy for treatment of CRC. The present review did not only focus upon the latest research findings, but earlier reviews were also cited as references to older literature.


Subject(s)
Colorectal Neoplasms , DNA Methylation , Epigenesis, Genetic , Humans , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Biomarkers, Tumor/genetics , Gene Expression Regulation, Neoplastic , Animals
6.
Neurosci Bull ; 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39014176

ABSTRACT

Posttraumatic stress disorder (PTSD) is a complex mental disorder notable for traumatic experience memory. Although current first-line treatments are linked with clinically important symptom reduction, a large proportion of patients retained to experience considerable residual symptoms, indicating pathogenic mechanism should be illustrated further. Recent studies reported that newly formed myelin could shape neural circuit function and be implicated in fear memory preservation. However, its role in PTSD remains to be elucidated. In this study, we adopted a restraint stress-induced PTSD mouse model and found that PTSD-related neuropsychiatric symptoms were accompanied by increased myelination in the posterior parietal cortex and hippocampus. Fluoxetine, but not risperidone or sertraline, has a more profound rescue effect on neuropsychological behaviors and myelin abnormalities. Further mechanistic experiments revealed that fluoxetine could directly interfere with oligodendroglial differentiation by upregulating Wnt signaling. Our data demonstrated the correlation between PTSD and abnormal myelination, suggesting that the oligodendroglial lineage could be a target for PTSD treatment.

7.
ChemMedChem ; : e202400349, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38965060

ABSTRACT

Bacterial infection, which can trigger varieties of diseases and tens of thousands of deaths each year, poses  serious threats to human health. Particularly, the new dilemma caused by biofilms is gradually becoming a severe and tough problem in the biomedical field. Thus, the strategies to address these problems are considered an urgent task at present. Micro/nanomotors (MNMs), also named micro/nanoscale robots, are mostly driven by chemical energy or external field, exhibiting strong diffusion and self-propulsion in the liquid media, which has the potential for antibacterial applications. In particular, when MNMs are assembled in swarms, they become robust and efficient for biofilm removal. However, there is a lack of comprehensive review discussing the progress in this aspect. Bearing it in mind and based on our own research experience in this regard, the studies on MNMs driven by different mechanisms orchestrated for antibacterial activity and biofilm removal are timely and concisely summarized and discussed in this work, aiming to show the advantages of MNMs brought to this field. In addition, an outlook was proposed, hoping to provide the fundamental guidance for future development in this area.

8.
Clin Lab ; 70(7)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38965963

ABSTRACT

BACKGROUND: Immunohematology skill education is an important part of the transfusion medicine professional training. We tried to solve the difficulty of obtaining suitable and sufficient positive samples in the immunohematology education. METHODS: Different identification panels and panel cells were created by RhD-positive red blood cells (RBCs) and RhD-negative RBCs, according to the underlying antibodies. Diluted anti-D reagent was used as simulated plasma for identification. RESULTS: The antibody identification of single antibody with dose-effect and two antibodies present at the same time were successfully simulated. CONCLUSIONS: It is a practical and cheap method for antibody identification training to use RhD blood group, especially when positive samples are short.


Subject(s)
Blood Grouping and Crossmatching , Rh-Hr Blood-Group System , Humans , Rh-Hr Blood-Group System/immunology , Rh-Hr Blood-Group System/blood , Blood Grouping and Crossmatching/methods , Erythrocytes/immunology , Isoantibodies/blood , Isoantibodies/immunology , Hematology/methods , Rho(D) Immune Globulin/immunology , Rho(D) Immune Globulin/blood , Transfusion Medicine/methods
9.
Phys Rev Lett ; 132(25): 250401, 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38996232

ABSTRACT

We propose a new approach to simulate the decoherence of a central spin coupled to an interacting dissipative spin bath with cluster-correlation expansion techniques. We benchmark the approach on generic 1D and 2D spin baths and find excellent agreement with numerically exact simulations. Our calculations show a complex interplay between dissipation and coherent spin exchange, leading to increased central spin coherence in the presence of fast dissipation. Finally, we model near-surface nitrogen-vacancy centers in diamond and show that accounting for bath dissipation is crucial to understanding their decoherence. Our method can be applied to a variety of systems and provides a powerful tool to investigate spin dynamics in dissipative environments.

11.
Biomed Pharmacother ; 177: 117163, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39018876

ABSTRACT

Graveoline exhibits various biological activities. However, only limited studies have focused on its hepatoprotective properties. This study evaluated the anti-inflammatory and hepatoprotective activities of graveoline, a minor 2-phenylquinolin-4-one alkaloid isolated from Ruta graveolens L., in a liver injury model in vitro and in vivo. A network pharmacology approach was used to investigate the potential signaling pathway associated with the hepatoprotective activity of graveoline. Subsequently, biological experiments were conducted to validate the findings. Topological analysis of the KEGG pathway enrichment revealed that graveoline mediates its hepatoprotective activity through genes associated with the hepatitis B viral infection pathway. Biological experiments demonstrated that graveoline effectively reduced the levels of alanine transaminase and aspartate transaminase in lipopolysaccharide (LPS)-induced HepG2 cells. Graveoline exerted antihepatitic activity by inhibiting the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and elevated the anti-inflammatory cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10) in vitro and in vivo. Additionally, graveoline exerted its hepatoprotective activity by inhibiting JAK1 and STAT3 phosphorylation both in vitro and in vivo. In summary, graveoline can attenuate acute liver injury by inhibiting the TNF-α inflammasome, activating IL-4 and IL-10, and suppressing the JAK1/STAT3 signaling pathway. This study sheds light on the potential of graveoline as a promising therapeutic agent for treating liver injury.

12.
Article in English | MEDLINE | ID: mdl-39018990

ABSTRACT

The isoelectric focusing has realized various improvements, including the protocols and creation of mIEF (microcolumn isoelectric focusing) instruments with excellent sensitivity for screening of diabetes and beta thalassemia. However, the problem of manual sample loading and hydration for the mIEF limits the operational capacity for stably detecting and quantitating most abnormal hemoglobin (Hb). Herein, we provided a high stable sample loading protocol for analysis of alpha thalassemia and Hb variants. In contrast to the previous volume of 20 µl, a 100 µl blood sample solution in this protocol was optimized with mixture of 6.4-7.5 and 3-10 pH carrier ampholytes, pI markers and loaded for 30 mins IPG microcolumn hydration. The hydrated microcolumn was then automatically loaded onto the mIEF chip array to which CH3COOH and NH4OH act as anodic and cathodic solutions. Lastly, the IEF was run for 9 mins. Hb H, Barts, A1c, F, A2 and CS were simultaneously separated and focused with higher resolution and sensitivity in quantifying H and Barts as low as 0.6 and 0.5 % respectively. Accordingly, there was an enhanced stability and linearity with a rapid assay time of 45 secs per sample. Moreover, analysis showed a fitting linear relationship with conventional technology at R2 = 0.9803 for H and R2 = 0.9728 for Barts thereby indicating greater accuracy confirmed by the AUC. Hence, the developed protocol could simply be employed for high stable and throughput batch sample loading of hydration, and accurate separation and quantitation of Hb variants for alpha and beta thalassemia.

13.
Sensors (Basel) ; 24(12)2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38931492

ABSTRACT

A staggered vane-shaped slot-line slow-wave structure (SV-SL SWS) for application in W-band traveling wave tubes (TWTs) is proposed in this article. In contrast to the conventional slot-line SWSs with dielectric substrates, the proposed SWS consists only of a thin metal sheet inscribed with periodic grooves and two half-metal enclosures, which means it can be easily manufactured and assembled and has the potential for mass production. This SWS not only solves the problem of the dielectric loading effect but also improves the heat dissipation capability of such structures. Meanwhile, the SWS design presented here covers a -15 dB S11 frequency range from 87.5 to 95 GHz. The 3-D simulation for a TWT based on the suggested SWS is also investigated. Under dual-electron injection conditions with a total voltage of 17.2 kV and a total current of 0.3 A, the maximum output power at 90 GHz is 200 W, with a 3 dB bandwidth up to 4 GHz. With a good potential for fabrication using microfabrication techniques, this structure can be a good candidate for millimeter-wave TWT applications.

14.
Vet Res ; 55(1): 80, 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38886823

ABSTRACT

Bacteria utilize intercellular communication to orchestrate essential cellular processes, adapt to environmental changes, develop antibiotic tolerance, and enhance virulence. This communication, known as quorum sensing (QS), is mediated by the exchange of small signalling molecules called autoinducers. AI-2 QS, regulated by the metabolic enzyme LuxS (S-ribosylhomocysteine lyase), acts as a universal intercellular communication mechanism across gram-positive and gram-negative bacteria and is crucial for diverse bacterial processes. In this study, we demonstrated that in Streptococcus suis (S. suis), a notable zoonotic pathogen, AI-2 QS enhances galactose utilization, upregulates the Leloir pathway for capsular polysaccharide (CPS) precursor production, and boosts CPS synthesis, leading to increased resistance to macrophage phagocytosis. Additionally, our molecular docking and dynamics simulations suggest that, similar to S. pneumoniae, FruA, a fructose-specific phosphoenolpyruvate phosphotransferase system prevalent in gram-positive pathogens, may also function as an AI-2 membrane surface receptor in S. suis. In conclusion, our study demonstrated the significance of AI-2 in the synthesis of galactose metabolism-dependent CPS in S. suis. Additionally, we conducted a preliminary analysis of the potential role of FruA as a membrane surface receptor for S. suis AI-2.


Subject(s)
Galactose , Quorum Sensing , Streptococcus suis , Streptococcus suis/physiology , Galactose/metabolism , Quorum Sensing/physiology , Virulence , Animals , Bacterial Capsules/metabolism , Lactones/metabolism , Streptococcal Infections/veterinary , Streptococcal Infections/microbiology , Streptococcal Infections/immunology , Homoserine/analogs & derivatives , Homoserine/metabolism , Polysaccharides, Bacterial/metabolism
15.
J Phys Chem A ; 128(27): 5243-5252, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38937149

ABSTRACT

Direct methanol fuel cells (DMFCs) have attracted increasing attention as a very promising and important energy source. In this paper, density functional theory (DFT) is used to study the structure and O-H fracture mechanism of methanol adsorption on PtnCu4-n (111) (n = 1, 2, 3) binary metal catalyst surfaces under different coverages. By comparing the adsorption energy and dehydrogenation energy barriers of methanol, it is found that the adsorption strength and dehydrogenation energy barriers of methanol on Pt and Cu sites decreased with increasing coverage. At the same Pt and Cu ratio, methanol is more easily adsorbed on Cu sites. When Pt/Cu = 3:1 and 1:3, the PtCu binary catalyst has a significant impact on the energy barrier of breaking the O-H bond in methanol with the increase of coverage. Especially when Pt/Cu = 1:3 and the coverage is 1/4 ML, the energy barriers of O-H bond breaking in methanol on Pt and Cu sites are 0.63 and 0.61 eV, respectively, which are lower than that on pure Pt. It means that the Cu sites played a very important role in reducing the O-H fracture energy barrier of methanol. When Pt/Cu = 1:1, the change in the dehydrogenation energy barrier of methanol on Pt sites and Cu sites is not significant, indicating that the coverage has little effect on it.

16.
J Org Chem ; 89(13): 9381-9388, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38885147

ABSTRACT

A Pd(II)/N,N'-disulfonyl bisimidazoline-catalyzed asymmetric 1,4-conjugate addition reaction of low-cost arylboronic acids with readily available ß-substituted cyclic enones is described, providing a straightforward way of constructing cyclic all-carbon quaternary stereocenters with high enantioselectivity, in which ≥96% ee was obtained in most cases. The reaction proceeded without the protection of inert gas, making the operation process simple. Theoretical calculations have been applied to understand the origins of enantioselectivity.

17.
BMC Psychiatry ; 24(1): 475, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38937737

ABSTRACT

BACKGROUND: This study aimed to explore discrepancies in adolescents with chronic illness and their parents' perceptions of family resilience, as well as the relationship between these differences and the psychological adjustment of adolescents with chronic illness. METHODS: A cross-sectional study was conducted. A total of 264 dyads of parents (77.7% mothers, mean age 41.60 years, SD = 6.17) and adolescents (48.5% girls, mean age 12.68 years, SD = 2.11) with chronic illness were recruited through convenience sampling from three children's hospitals in Wenzhou, Hangzhou, and Shanghai, China between June 2022 and May 2023. The Chinese version of the Family Resilience Scale and the Psychological Adjustment Scale, which are commonly used measures with good reliability and validity, were employed to assess family resilience and psychological adaption, respectively. The data were analyzed using polynomial regression and response surface analysis. RESULTS: Adolescents with chronic illness reported higher family resilience than their parents (t=-2.80, p < 0.05). The correlations between family resilience and adolescents' psychological adjustment reported by the adolescents (r = 0.45-0.48) were higher than parents (r = 0.18-0.23). In the line of congruence, there were positive linear (a1 = 1.09-1.60, p < 0.001) and curvilinear (a2=-1.38∼-0.72, p < 0.05) associations between convergent family resilience and adolescents' psychological adjustment. In the line of incongruence, when adolescents reported lower family resilience than parents, adolescents had a lower level of psychological adjustment (a3=-1.02∼-0.45, p < 0.05). Adolescents' sociability decreased when the perceived family resilience of parent-adolescent dyads converged (a4 = 1.36, p < 0.01). CONCLUSION: The findings highlighted the importance of considering the discrepancies and congruence of family resilience in the parent-child dyads when developing interventions to improve the psychological adjustment of adolescents with chronic illness. Interventions aimed at strengthening family communication to foster the convergence of perceptions of family resilience in parent-adolescent dyads were warranted.


Subject(s)
Emotional Adjustment , Parents , Resilience, Psychological , Humans , Female , Adolescent , Male , Chronic Disease/psychology , Cross-Sectional Studies , Parents/psychology , Adult , Child , China , Adaptation, Psychological , Family/psychology , Middle Aged
18.
Biosens Bioelectron ; 261: 116492, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38870828

ABSTRACT

Exosomes have been considered as promising biomarkers for cancer diagnosis due to their abundant information from originating cells. However, sensitive and reliable detection of exosomes is still facing technically challenges due to the lack of a sensing platform with high sensitivity and reproducibility. To address the challenges, here we propose a portable surface plasmon resonance (SPR) sensing of exosomes with a three-layer Au mirror/SiO2 spacer/Au nanohole sensor, fabricated by an economical polystyrene nanosphere self-assembly method. The SiO2 spacer can act as an optical cavity and induce mode hybridization, leading to excellent optimization of both sensitivity and full width at half maximum compared with normal single layer Au nanohole sensors. When modified with CD63 or EpCAM aptamers, a detection of limit (LOD) of as low as 600 particles/µL was achieved. The sensors showed good capability to distinguish between non-tumor derived L02 exosomes and tumor derived HepG2 exosomes. Additionally, high reproducibility was also achieved in detection of artificial serum samples with RSD as low as 2%, making it feasible for clinical applications. This mode hybridization plasmonic sensor provides an effective approach to optimize the detection sensitivity of exosomes, pushing SPR sensing one step further towards cancer diagnosis.


Subject(s)
Exosomes , Gold , Limit of Detection , Silicon Dioxide , Surface Plasmon Resonance , Exosomes/chemistry , Humans , Gold/chemistry , Silicon Dioxide/chemistry , Aptamers, Nucleotide/chemistry , Epithelial Cell Adhesion Molecule , Tetraspanin 30 , Hep G2 Cells , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Reproducibility of Results , Equipment Design , Nanospheres/chemistry , Nucleic Acid Hybridization , Biomarkers, Tumor/blood , Biomarkers, Tumor/analysis
19.
Lab Invest ; 104(8): 102090, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38830579

ABSTRACT

Gastric cancer (GC) is one of the most common clinical malignant tumors worldwide, with high morbidity and mortality. Presently, the overall response rate to immunotherapy is low, and current methods for predicting the prognosis of GC are not optimal. Therefore, novel biomarkers with accuracy, efficiency, stability, performance ratio, and wide clinical application are needed. Based on public data sets, the chemotherapy cohort and immunotherapy cohort from Sun Yat-sen University Cancer Center, a series of bioinformatics analyses, such as differential expression analysis, survival analysis, drug sensitivity prediction, enrichment analysis, tumor immune dysfunction and exclusion analysis, single-sample gene set enrichment analysis, stemness index calculation, and immune cell infiltration analysis, were performed for screening and preliminary exploration. Immunohistochemical staining and in vitro experiments were performed for further verification. Overexpression of COX7A1 promoted the resistance of GC cells to Oxaliplatin. COX7A1 may induce immune escape by regulating the number of fibroblasts and their cellular communication with immune cells. In summary, measuring the expression levels of COX7A1 in the clinic may be useful in predicting the prognosis of GC patients, the degree of chemotherapy resistance, and the efficacy of immunotherapy.

20.
J Neurosci ; 44(28)2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38858079

ABSTRACT

Tau pathologies are detected in the brains of some of the most common neurodegenerative diseases including Alzheimer's disease (AD), Lewy body dementia (LBD), chronic traumatic encephalopathy (CTE), and frontotemporal dementia (FTD). Tau proteins are expressed in six isoforms with either three or four microtubule-binding repeats (3R tau or 4R tau) due to alternative RNA splicing. AD, LBD, and CTE brains contain pathological deposits of both 3R and 4R tau. FTD patients can exhibit either 4R tau pathologies in most cases or 3R tau pathologies less commonly in Pick's disease, which is a subfamily of FTD. Here, we report the isoform-specific roles of tau in FTD. The P301L mutation, linked to familial 4R tau FTD, induces mislocalization of 4R tau to dendritic spines in primary hippocampal cultures that were prepared from neonatal rat pups of both sexes. Contrastingly, the G272V mutation, linked to familial Pick's disease, induces phosphorylation-dependent mislocalization of 3R tau but not 4R tau proteins to dendritic spines. The overexpression of G272V 3R tau but not 4R tau proteins leads to the reduction of dendritic spine density and suppression of mEPSCs in 5-week-old primary rat hippocampal cultures. The decrease in mEPSC amplitude caused by G272V 3R tau is dynamin-dependent whereas that caused by P301L 4R tau is dynamin-independent, indicating that the two tau isoforms activate different signaling pathways responsible for excitatory synaptic dysfunction. Our 3R and 4R tau studies here will shed new light on diverse mechanisms underlying FTD, AD, LBD, and CTE.


Subject(s)
Dendritic Spines , Frontotemporal Dementia , Mutation , Protein Isoforms , tau Proteins , tau Proteins/metabolism , tau Proteins/genetics , Animals , Frontotemporal Dementia/genetics , Frontotemporal Dementia/metabolism , Frontotemporal Dementia/pathology , Dendritic Spines/metabolism , Dendritic Spines/pathology , Rats , Male , Humans , Female , Protein Isoforms/genetics , Protein Isoforms/metabolism , Synapses/metabolism , Synapses/pathology , Rats, Sprague-Dawley , Hippocampus/metabolism , Hippocampus/pathology , Cells, Cultured
SELECTION OF CITATIONS
SEARCH DETAIL
...