RESUMO
Heteroplasmy occurs when wild-type and mutant mitochondrial DNA (mtDNA) molecules co-exist in single cells1. Heteroplasmy levels change dynamically in development, disease and ageing2,3, but it is unclear whether these shifts are caused by selection or drift, and whether they occur at the level of cells or intracellularly. Here we investigate heteroplasmy dynamics in dividing cells by combining precise mtDNA base editing (DdCBE)4 with a new method, SCI-LITE (single-cell combinatorial indexing leveraged to interrogate targeted expression), which tracks single-cell heteroplasmy with ultra-high throughput. We engineered cells to have synonymous or nonsynonymous complex I mtDNA mutations and found that cell populations in standard culture conditions purge nonsynonymous mtDNA variants, whereas synonymous variants are maintained. This suggests that selection dominates over simple drift in shaping population heteroplasmy. We simultaneously tracked single-cell mtDNA heteroplasmy and ancestry, and found that, although the population heteroplasmy shifts, the heteroplasmy of individual cell lineages remains stable, arguing that selection acts at the level of cell fitness in dividing cells. Using these insights, we show that we can force cells to accumulate high levels of truncating complex I mtDNA heteroplasmy by placing them in environments where loss of biochemical complex I activity has been reported to benefit cell fitness. We conclude that in dividing cells, a given nonsynonymous mtDNA heteroplasmy can be harmful, neutral or even beneficial to cell fitness, but that the 'sign' of the effect is wholly dependent on the environment.
Assuntos
Divisão Celular , Linhagem da Célula , DNA Mitocondrial , Aptidão Genética , Heteroplasmia , Seleção Genética , Análise de Célula Única , Animais , Feminino , Humanos , Camundongos , Divisão Celular/genética , Linhagem Celular , Linhagem da Célula/genética , DNA Mitocondrial/genética , Edição de Genes , Heteroplasmia/genética , Mitocôndrias/genética , Mutação , Análise de Célula Única/métodosRESUMO
In the eukaryotic cytosol, the Hsp70 and the Hsp90 chaperone machines work in tandem with the maturation of a diverse array of client proteins. The transfer of nonnative clients between these systems is essential to the chaperoning process, but how it is regulated is still not clear. We discovered that NudC is an essential transfer factor with an unprecedented mode of action: NudC interacts with Hsp40 in Hsp40-Hsp70-client complexes and displaces Hsp70. Then, the interaction of NudC with Hsp90 allows the direct transfer of Hsp40-bound clients to Hsp90 for further processing. Consistent with this mechanism, NudC increases client activation in vitro as well as in cells and is essential for cellular viability. Together, our results show the complexity of the cooperation between the major chaperone machineries in the eukaryotic cytosol.
Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas Nucleares/metabolismo , Sítios de Ligação , Proteínas de Ciclo Celular/genética , Sobrevivência Celular , Células HEK293 , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP90/genética , Humanos , Células K562 , Cinética , Simulação de Acoplamento Molecular , Proteínas Nucleares/genética , Ligação Proteica , Dobramento de Proteína , Domínios e Motivos de Interação entre Proteínas , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
In mammalian cells, mitochondrial dysfunction triggers the integrated stress response, in which the phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) results in the induction of the transcription factor ATF41-3. However, how mitochondrial stress is relayed to ATF4 is unknown. Here we show that HRI is the eIF2α kinase that is necessary and sufficient for this relay. In a genome-wide CRISPR interference screen, we identified factors upstream of HRI: OMA1, a mitochondrial stress-activated protease; and DELE1, a little-characterized protein that we found was associated with the inner mitochondrial membrane. Mitochondrial stress stimulates OMA1-dependent cleavage of DELE1 and leads to the accumulation of DELE1 in the cytosol, where it interacts with HRI and activates the eIF2α kinase activity of HRI. In addition, DELE1 is required for ATF4 translation downstream of eIF2α phosphorylation. Blockade of the OMA1-DELE1-HRI pathway triggers an alternative response in which specific molecular chaperones are induced. The OMA1-DELE1-HRI pathway therefore represents a potential therapeutic target that could enable fine-tuning of the integrated stress response for beneficial outcomes in diseases that involve mitochondrial dysfunction.
Assuntos
Citosol/metabolismo , Metaloendopeptidases/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , Estresse Fisiológico , eIF-2 Quinase/metabolismo , Fator 4 Ativador da Transcrição/biossíntese , Fator 4 Ativador da Transcrição/metabolismo , Sistemas CRISPR-Cas , Linhagem Celular , Citosol/enzimologia , Ativação Enzimática , Fator de Iniciação 2 em Eucariotos/metabolismo , Humanos , Masculino , Proteínas Mitocondriais/química , Chaperonas Moleculares/metabolismo , Fosforilação , Ligação ProteicaRESUMO
Iron-sulfur clusters (ISC) are essential cofactors that participate in electron transfer, environmental sensing, and catalysis. Amongst the most ancient ISC-containing proteins are the ferredoxin (FDX) family of electron carriers. Humans have two FDXs- FDX1 and FDX2, both of which are localized to mitochondria, and the latter of which is itself important for ISC synthesis. We have previously shown that hypoxia can eliminate the requirement for some components of the ISC biosynthetic pathway, but FDXs were not included in that study. Here, we report that FDX1, but not FDX2, is dispensable under 1% O2 in cultured human cells. We find that FDX1 is essential for production of the lipoic acid cofactor, which is synthesized by the ISC-containing enzyme lipoyl synthase. While hypoxia can rescue the growth phenotype of either FDX1 or lipoyl synthase KO cells, lipoylation in these same cells is not rescued, arguing against an alternative biosynthetic route or salvage pathway for lipoate in hypoxia. Our work reveals the divergent roles of FDX1 and FDX2 in mitochondria, identifies a role for FDX1 in lipoate synthesis, and suggests that loss of lipoic acid can be tolerated under low oxygen tensions in cell culture.
Assuntos
Ferredoxinas , Lipoilação , Humanos , Ferredoxinas/genética , Ferredoxinas/metabolismo , Ácido Tióctico/metabolismo , Hipóxia Celular/efeitos dos fármacos , Técnicas de Inativação de Genes , Oxigênio/farmacologia , Proteoma/efeitos dos fármacos , Proteoma/genética , Sulfurtransferases/genética , Sulfurtransferases/metabolismo , Sítios de Ligação , Estabilidade Proteica , Biossíntese de Proteínas/efeitos dos fármacosRESUMO
The fabrication of microarray chips and the precise dispensing of nanoliter to microliter liquids are fundamental for high-throughput parallel biochemical testing. Conventional microwells, typically featuring a uniform cross section, fill completely in a single operation, complicating the introduction of multiple reagents for stepwise and combinatorial analyses. To overcome this limitation, we developed an innovative valved microwell array. Using ultraviolet (UV)-curing resin three-dimensional (3D) printing, these multilayer configurations can be rapidly fabricated through direct template printing and polydimethylsiloxane (PDMS) casting. Each microwell incorporates a microvalve structure, truncating fluids within the upper metering well and allowing transfer to the bottom reservoir well under centrifugal force. Sequential operations enable the introduction of multiple reagents, facilitating orthogonal combinations for complex assays. We explored four types of valving methods: DeepWell, Expansion, Bottleneck, and Membrane valve, each offering varying degrees of design complexity, operational efficiency, robustness, and precision. These methods constitute a versatile toolkit to accommodate a broad spectrum of analytical requirements. Our innovative approach redefines microwell architecture, direct manufacturing techniques, and stepwise fluid dispensation in microarrays.
Assuntos
Dimetilpolisiloxanos , Dimetilpolisiloxanos/química , Impressão Tridimensional , Análise em Microsséries , Técnicas Analíticas Microfluídicas/instrumentaçãoRESUMO
This study presents a case of a female infertile patient suffering from embryonic arrest and recurrent implantation failure. The primary objective was to assess the copy number variations (CNVs) and DNA methylation of her embryos. Genetic diagnosis was conducted by whole-exome sequencing and validated through Sanger sequencing. CNV evaluation of two cleavage stage embryos was performed using whole-genome sequencing, while DNA methylation and CNV assessment of two blastocysts were carried out using whole-genome bisulfite sequencing. We identified two novel pathogenic frameshift variants in the MEI1 gene (NM_152513.3, c.3002delC, c.2264_2268 + 11delGTGAGGTATGGACCAC) in the proband. These two variants were inherited from her heterozygous parents, consistent with autosomal recessive genetic transmission. Notably, two Day 3 embryos and two Day 6 blastocysts were all aneuploid, with numerous monosomy and trisomy events. Moreover, global methylation levels greatly deviated from the optimized window of 0.25-0.27, measuring 0.344 and 0.168 for the respective blastocysts. This study expands the mutational spectrum of MEI1 and is the first to document both aneuploidy and abnormal methylation levels in embryos from a MEI1-affected female patient presenting with embryonic arrest. Given that females affected by MEI1 mutations might experience either embryonic arrest or monospermic androgenetic hydatidiform moles due to the extrusion of all maternal chromosomes, the genetic makeup of the arrested embryos of MEI1 patients provides important clues for understanding the different disease mechanisms of the two phenotypes.
Assuntos
Variações do Número de Cópias de DNA , Metilação de DNA , Humanos , Feminino , Gravidez , Metilação de DNA/genética , Variações do Número de Cópias de DNA/genética , Mutação , Aneuploidia , Cromossomos , Proteínas de Ciclo CelularRESUMO
Constructing structural defects is a promising way to enhance the catalytic activity toward the hydrogen evolution reaction (HER). However, the relationship between defect density and HER activity has rarely been discussed. In this study, a series of Pt/WOx nanocrystals are fabricated with controlled morphologies and structural defect densities using a facile one-step wet chemical method. Remarkably, compared with polygonal and star structures, the dendritic Pt/WOx (d-Pt/WOx) exhibited a richer structural defect density, including stepped surfaces and atomic defects. Notably, the d-Pt/WOx catalyst required 4 and 16 mV to reach 10 mA cm-2, and its turnover frequency (TOF) values are 11.6 and 22.8 times higher than that of Pt/C under acidic and alkaline conditions, respectively. In addition, d-Pt/WOx//IrO2 displayed a mass activity of 5158 mA mgPt -1 at 2.0 V in proton exchange membrane water electrolyzers (PEMWEs), which is significantly higher than that of the commercial Pt/C//IrO2 system. Further mechanistic studies suggested that the d-Pt/WOx exhibited reduced number of antibonding bands and the lowest dz2-band center, contributing to hydrogen adsorption and release in acidic solution. The highest dz2-band center of d-Pt/WOx facilitated the adsorption of hydrogen from water molecules and water dissociation in alkaline medium. This work emphasizes the key role of the defect density in improving the HER activity of electrocatalysts.
RESUMO
Strain engineering is an effective strategy for manipulating the electronic structure of active sites and altering the binding strength toward adsorbates during the hydrogen evolution reaction (HER). However, the effects of weak and strong strain engineering on the HER catalytic activity have not been fully explored. Herein, the core-shell PdPt alloys with two-layer Pt shells (PdPt2L) and multi-layer Pt shells (PdPtML) is constructed, which exhibit distinct lattice strains. Notably, PdPt2L with weak strain effect just requires a low overpotential of 18 mV to reach 10 mA cm-2 for the HER and shows the superior long-term stability for 510 h with negligible activity degradation in 0.5 M H2SO4. The intrinsic activity of PdPt2L is 6.2 and 24.5 times higher than that of PdPtML and commercial Pt/C, respectively. Furthermore, PdPt2L||IrO2 exhibits superior activity over Pt/C||IrO2 in proton exchange membrane water electrolyzers and maintains stable operation for 100 h at large current density of 500 mA cm-2. In situ/operando measurements verify that PdPt2L exhibits lower apparent activation energy and accelerated ad-/desorption kinetics, benefiting from the weak strain effect. Density functional theory calculations also reveal that PdPt2L displays weaker H* adsorption energy compared to PdPtML, favoring for H* desorption and promoting H2 generation.
RESUMO
Irritable bowel syndrome (IBS), a chronic functional gastrointestinal disorder, is recognized for its association with alterations in the gut microbiome and metabolome. This study delves into the largely unexplored domain of the gut virome in IBS patients. We conducted a comprehensive analysis of the fecal metagenomic data set from 277 IBS patients and 84 healthy controls to characterize the gut viral community. Our findings revealed a distinct gut virome in IBS patients compared to healthy individuals, marked by significant variances in between-sample diversity and altered abundances of 127 viral operational taxonomic units (vOTUs). Specifically, 111 vOTUs, predominantly belonging to crAss-like, Siphoviridae, Myoviridae, and Quimbyviridae families, were more abundant in IBS patients, whereas the healthy control group exhibited enrichment of 16 vOTUs from multiple families. We also investigated the interplay between the gut virome and bacteriome, identifying a correlation between IBS-enriched bacteria like Klebsiella pneumoniae, Fusobacterium varium, and Ruminococcus gnavus, and the IBS-associated vOTUs. Furthermore, we assessed the potential of gut viral signatures in predicting IBS, achieving a notable area under the receiver operator characteristic curve (AUC) of 0.834. These findings highlight significant shifts in the viral diversity, taxonomic distribution, and functional composition of the gut virome in IBS patients, suggesting the potential role of the gut virome in IBS pathogenesis and opening new avenues for diagnostic and therapeutic strategies targeting the gut virome in IBS management.
Assuntos
Fezes , Microbioma Gastrointestinal , Síndrome do Intestino Irritável , Metagenômica , Viroma , Humanos , Síndrome do Intestino Irritável/virologia , Síndrome do Intestino Irritável/microbiologia , Microbioma Gastrointestinal/genética , Fezes/virologia , Fezes/microbiologia , Vírus/classificação , Vírus/genética , Vírus/isolamento & purificação , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , MetagenomaRESUMO
Pancreatic cancer (PC) is a highly aggressive malignancy with a poor prognosis, making early diagnosis crucial for improving patient outcomes. While the gut microbiome, including bacteria and viruses, is believed to be essential in cancer pathogenicity, the potential contribution of the gut virome to PC remains largely unexplored. In this study, we conducted a comparative analysis of the gut viral compositional and functional profiles between PC patients and healthy controls, based on fecal metagenomes from two publicly available data sets comprising a total of 101 patients and 82 healthy controls. Our results revealed a decreasing trend in the gut virome diversity of PC patients with disease severity. We identified significant alterations in the overall viral structure of PC patients, with a meta-analysis revealing 219 viral operational taxonomic units (vOTUs) showing significant differences in relative abundance between patients and healthy controls. Among these, 65 vOTUs were enriched in PC patients, and 154 were reduced. Host prediction revealed that PC-enriched vOTUs preferentially infected bacterial members of Veillonellaceae, Enterobacteriaceae, Fusobacteriaceae, and Streptococcaceae, while PC-reduced vOTUs were more likely to infect Ruminococcaceae, Lachnospiraceae, Clostridiaceae, Oscillospiraceae, and Peptostreptococcaceae. Furthermore, we constructed random forest models based on the PC-associated vOTUs, achieving an optimal average area under the curve (AUC) of up to 0.879 for distinguishing patients from controls. Through additional 10 public cohorts, we demonstrated the reproducibility and high specificity of these viral signatures. Our study suggests that the gut virome may play a role in PC development and could serve as a promising target for PC diagnosis and therapeutic intervention. Future studies should further explore the underlying mechanisms of gut virus-bacteria interactions and validate the diagnostic models in larger and more diverse populations.
Assuntos
Fezes , Microbioma Gastrointestinal , Metagenômica , Neoplasias Pancreáticas , Viroma , Humanos , Neoplasias Pancreáticas/virologia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/microbiologia , Microbioma Gastrointestinal/genética , Metagenômica/métodos , Fezes/virologia , Fezes/microbiologia , Vírus/isolamento & purificação , Vírus/genética , Vírus/classificação , Metagenoma , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Pessoa de Meia-Idade , Masculino , Feminino , Idoso , Estudos de Casos e ControlesRESUMO
INTRODUCTION: Sepsis is a highly morbid condition characterized by multi-organ dysfunction resulting from dysregulated inflammation in response to acute infection. Mitochondrial dysfunction may contribute to sepsis pathogenesis, but quantifying mitochondrial dysfunction remains challenging. OBJECTIVE: To assess the extent to which circulating markers of mitochondrial dysfunction are increased in septic shock, and their relationship to severity and mortality. METHODS: We performed both full-scan and targeted (known markers of genetic mitochondrial disease) metabolomics on plasma to determine markers of mitochondrial dysfunction which distinguish subjects with septic shock (n = 42) from cardiogenic shock without infection (n = 19), bacteremia without sepsis (n = 18), and ambulatory controls (n = 19) - the latter three being conditions in which mitochondrial function, proxied by peripheral oxygen consumption, is presumed intact. RESULTS: Nine metabolites were significantly increased in septic shock compared to all three comparator groups. This list includes N-formyl-L-methionine (f-Met), a marker of dysregulated mitochondrial protein translation, and N-lactoyl-phenylalanine (lac-Phe), representative of the N-lactoyl-amino acids (lac-AAs), which are elevated in plasma of patients with monogenic mitochondrial disease. Compared to lactate, the clinical biomarker used to define septic shock, there was greater separation between survivors and non-survivors of septic shock for both f-Met and the lac-AAs measured within 24 h of ICU admission. Additionally, tryptophan was the one metabolite significantly decreased in septic shock compared to all other groups, while its breakdown product kynurenate was one of the 9 significantly increased. CONCLUSION: Future studies which validate the measurement of lac-AAs and f-Met in conjunction with lactate could define a sepsis subtype characterized by mitochondrial dysfunction.
Assuntos
Doenças Mitocondriais , Sepse , Choque Séptico , Humanos , Aminoácidos , N-Formilmetionina , Metabolômica , Metionina , Ácido Láctico , RacemetioninaRESUMO
BACKGROUND: Reduced endometrium thickness and receptivity are two important reasons for recurrent implantation failure (RIF). In order to elucidate differences between these two types of endometrial defects in terms of molecular signatures, cellular interactions, and structural changes, we systematically investigated the single-cell transcriptomic atlas across three distinct groups: RIF patients with thin endometrium (≤ 6 mm, TE-RIF), RIF patients with normal endometrium thickness (≥ 8 mm, NE-RIF), and fertile individuals (Control). METHODS: The late proliferative and mid-secretory phases of the endometrium were collected from three individuals in the TE-RIF group, two in the NE-RIF group, and three in the control group. The study employed a combination of advanced techniques. Single-cell RNA sequencing (scRNA-seq) was utilized to capture comprehensive transcriptomic profiles at the single-cell level, providing insights into gene expression patterns within specific cell types. Scanning and transmission electron microscopy were employed to visualize ultrastructural details of the endometrial tissue, while hematoxylin and eosin staining facilitated the examination of tissue morphology and cellular composition. Immunohistochemistry techniques were also applied to detect and localize specific protein markers relevant to endometrial receptivity and function. RESULTS: Through comparative analysis of differentially expressed genes among these groups and KEGG pathway analysis, the TE-RIF group exhibited notable dysregulations in the TNF and MAPK signaling pathways, which are pivotal in stromal cell growth and endometrial receptivity. Conversely, in the NE-RIF group, disturbances in energy metabolism emerged as a primary contributor to reduced endometrial receptivity. Additionally, using CellPhoneDB for intercellular communication analysis revealed aberrant interactions between epithelial and stromal cells, impacting endometrial receptivity specifically in the TE-RIF group. CONCLUSION: Overall, our findings provide valuable insights into the heterogeneous molecular pathways and cellular interactions associated with RIF in different endometrial conditions. These insights may pave the way for targeted therapeutic interventions aimed at improving endometrial receptivity and enhancing reproductive outcomes in patients undergoing ART. Further research is warranted to validate these findings and translate them into clinical applications for personalized fertility treatments. TRIAL REGISTRATION: Not applicable.
Assuntos
Implantação do Embrião , Endométrio , Análise de Célula Única , Transcriptoma , Humanos , Feminino , Endométrio/metabolismo , Endométrio/patologia , Implantação do Embrião/genética , Implantação do Embrião/fisiologia , Adulto , Análise de Célula Única/métodos , Perfilação da Expressão Gênica/métodos , Infertilidade Feminina/genética , Infertilidade Feminina/metabolismo , Infertilidade Feminina/patologia , GravidezRESUMO
BACKGROUND: Atherosclerosis are well established risk factors for ischemic stroke, however the association between alcohol consumption and atherosclerosis is controversial. This study aims to explore the potential correlation between alcohol consumption and cerebral stenosis in patients with acute ischemic stroke and transient ischemic attack (TIA). METHODS: Nine hundreds and eighty-eight patients with first acute ischemic stroke attack or TIA were recruited retrospectively. Alcohol consumption was classified into five consumption categories (non-drinkers, occasional drinkers, < 140 g per week [mild drinkers], 140-279 g per week [moderate drinkers], ≥ 280 g per week [heavy drinkers]). Computed tomography angiography (CTA) and digital subtraction angiography (DSA) were utilized to assess the carotid and cerebral artery in all patients. Five-step scale for degree of stenosis was applied: normal (0, 0 points), mild (< 50%, 1 point), moderate (50-69%, 2 points), severe (70-99%, 3 points), and occlusion (100%, 4 points). RESULTS: The carotid and cerebral artery stenosis scores were positively correlated with moderate alcohol consumption (B = 1.695, P < 0.001). Compared with nondrinkers, moderate alcohol consumption had significant increasing risk of moderate carotid and cerebral artery stenosis (OR = 4.28, 95% CI: 1.47-12.49, P = 0.008) and severe stenosis (OR = 4.24, 95% CI: 1.55-11.64, P = 0.005) and occlusion (OR = 3.87, 95% CI: 1.65-9.06, P = 0.002). Compared with nondrinkers, heavy alcohol consumption patients had significant higher risk of carotid and cerebral artery occlusion (OR = 2.71, 95% CI: 1.36-5.41, P = 0.005). CONCLUSIONS: Higher alcohol consumption may associate with higher risk and more severity of carotid and cerebrovascular stenosis.
Assuntos
Consumo de Bebidas Alcoólicas , Ataque Isquêmico Transitório , AVC Isquêmico , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Ataque Isquêmico Transitório/epidemiologia , Ataque Isquêmico Transitório/diagnóstico por imagem , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , Fatores de Risco , Idoso , AVC Isquêmico/epidemiologia , AVC Isquêmico/etiologia , Estudos Retrospectivos , Estenose das Carótidas/epidemiologia , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/complicações , Adulto , Idoso de 80 Anos ou mais , Angiografia por Tomografia Computadorizada/métodosRESUMO
OBJECTIVE: This study investigated the correlation between thyroid function and urinary iodine/creatinine ratio (UI/Cr) in pregnant women during different trimesters and explored potential influencing factors. METHODS: In this cross-sectional study, serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4), and UI/Cr were measured in 450 pregnant women. Correlations were analyzed using Pearson's correlation coefficient and multiple linear regression. Subgroup analyses were performed based on age, body mass index (BMI), parity, gestational age, education, occupation, and family history of thyroid disorders. RESULTS: UI/Cr was positively correlated with FT4 levels in the first and second trimesters, particularly in women with older age, higher BMI, multiparity, higher education, and employment. No significant correlations were found between UI/Cr and TSH or FT3 levels. CONCLUSION: UI/Cr is positively correlated with FT4 levels in early pregnancy, especially in women with certain risk factors. Regular monitoring of iodine status and thyroid function is recommended for pregnant women to ensure optimal maternal and fetal health.
Assuntos
Creatinina , Iodo , Trimestres da Gravidez , Centros de Atenção Terciária , Testes de Função Tireóidea , Humanos , Feminino , Gravidez , Iodo/urina , Estudos Transversais , Adulto , Creatinina/urina , Creatinina/sangue , Trimestres da Gravidez/urina , China/epidemiologia , Glândula Tireoide/fisiologia , Adulto Jovem , Doenças da Glândula Tireoide/epidemiologia , Doenças da Glândula Tireoide/urina , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/sangue , Tireotropina/sangue , Biomarcadores/urina , Biomarcadores/sangue , Tiroxina/sangue , Pequim/epidemiologia , Complicações na Gravidez/epidemiologia , Complicações na Gravidez/urinaRESUMO
BACKGROUND: Sepsis-associated encephalopathy (SAE) impairs hippocampal microglial efferocytosis, causing cognitive deficits. Previous research found that milk fat globule epidermal growth factor 8 protein (MFGE8) stimulates efferocytosis, reducing hippocampal inflammation in SAE rats. In this study, we explore MFGE8's role in alleviating cognitive impairment and its impact on neural activity using functional magnetic resonance imaging (fMRI). METHODS: Sixty male Sprague Dawley rats were divided into four groups: Sham, cecal ligation and puncture (CLP), CLP+MFGE8, and CLP+MFGE8+CGT (Cilengitide). After CLP, CLP+MFGE8 rats received intracerebroventricular MFGE8 (3.3 µg), while CLP+MFGE8+CGT rats received intraperitoneal Cilengitide (10 mg/kg). We assessed cognitive function with the Morris water maze and open field test over five days. Eight days post-surgery, rats underwent T2-weighted magnetic resonance imaging (MRI) and resting state (rs)-fMRI scans. Brain tissues were collected for western blot, hematoxylin-eosin (HE) staining, and immunofluorescence. Statistical analysis employed one-way analysis of variance (ANOVA) followed by Tukey's post-test for multiple comparisons. RESULTS: MFGE8 improved neurobehavioral performance in open field task (OFT) and morris water maze (MWM) tests. fMRI indicated a significant reduction in abnormal neural activity in the right hippocampal CA1, CA3, and dentate gyrus of SAE rats following MFGE8 treatment. Voxel-based morphometry (VBM) analysis revealed decreased high-signal areas in the hippocampus, along with reduced hippocampal volume due to alleviated neural edema. Western blot analysis demonstrated that MFGE8 enhanced ras-related C3 botulinum toxin substrate 1 (Rac1) and microtubule-associated protein 1A/1B-light chain 3 (LC3) expression in the rat hippocampus, while CGT reduced these protein levels. Behavioral experiments and fMRI results confirmed that CGT reversed the cognitive effects of MFGE8 by inhibiting microglial αVß3/αVß5 integrin receptors. CONCLUSIONS: Our findings show that MFGE8 reduced amplitude of low-frequency fluctuations (ALFF) values in the right hippocampal CA1, CA3, and the dentate gyrus, mitigating abnormal neural activity and decreasing hippocampal volume. This led to an improvement in cognitive dysfunction in SAE rats. These results suggest that MFGE8 enhances microglial efferocytosis by activating αVß3 and αVß5 integrin receptors on microglial surfaces, ultimately improving cognitive function in SAE rats.
Assuntos
Disfunção Cognitiva , Imageamento por Ressonância Magnética , Encefalopatia Associada a Sepse , Animais , Masculino , Ratos , Antígenos de Superfície/metabolismo , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/fisiopatologia , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/diagnóstico por imagem , Proteínas do Leite/farmacologia , Proteínas do Leite/administração & dosagem , Ratos Sprague-DawleyRESUMO
BACKGROUND: With the emergence of numerous scientific outputs, growing attention is paid to research misconduct. This study aimed to investigate knowledge, attitudes and practices about research misconduct among medical residents in southwest China. METHODS: A cross-sectional study was conducted in southwest China from November 2022 through March 2023. The links to the questionnaire were sent to the directors of the teaching management department in 17 tertiary hospitals. Answers were collected and analyzed. Logistic regression analysis was performed to explore the factors associated with research misconduct among residents. RESULTS: 6200 residents were enrolled in the study, and 88.5% of participants attended a course on research integrity, but 53.7% of participants admitted to having committed at least one form of research misconduct. Having a postgraduate or above, publishing papers as the first author or corresponding author, attending a course on research integrity, lower self-reported knowledge on research integrity and lower perceived consequences for research misconduct were positively correlated to research misconduct. Serving as a primary investigator for a research project was negatively associated with research misconduct. Most residents (66.3%) agreed that the reason for research misconduct is that researchers lack research ability. CONCLUSIONS: The high self-reported rate of research misconduct among residents in southwest China underscores a universal necessity for enhancing research integrity courses in residency programs. The ineffectiveness of current training in China suggests a possible global need for reevaluating and improving educational approaches to foster research integrity. Addressing these challenges is imperative not only for the credibility of medical research and patient care in China but also for maintaining the highest ethical standards in medical education worldwide. Policymakers, educators, and healthcare leaders on a global scale should collaborate to establish comprehensive strategies that ensure the responsible conduct of research, ultimately safeguarding the integrity of medical advancements and promoting trust in scientific endeavors across borders.
Assuntos
Internato e Residência , Má Conduta Científica , Humanos , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , ChinaRESUMO
Elevated stress levels are related to diminished mental health, potentially leading to decreased well-being and performance of nursing students. While researchers have focused on developing stress management interventions, there is a need to synthesize the evidence. A systematic review with meta-analysis was conducted to assess the evidence for the effectiveness of stress management interventions in nursing students. A systematic literature search identified controlled stress management interventions employing a validated psychological or physiological stress measure. Forty-one studies were included, with 36 forming a pool of 2715 participants in the meta-analysis. The overall effect on psychological stress was positive. Intervention type, delivery modality, intervention duration in weeks, and number of sessions were moderators of intervention effectiveness, with more significant effects for mind-body programs, on-site delivery methods, durations of 9-12 weeks, and 15-30 sessions. For physiological stress, the biomarkers of blood pressure, heart rate, and cortisol levels decreased significantly. Future research is necessary for promising outcomes related to currently underrepresented indicators and to investigate the long-term effects of interventions.
Assuntos
Estresse Psicológico , Estudantes de Enfermagem , Humanos , Estudantes de Enfermagem/psicologia , Estudantes de Enfermagem/estatística & dados numéricos , Estresse Psicológico/psicologiaRESUMO
OBJECTIVES: To analyze the pregnancy outcomes in patients with positive anti-centromere antibodies (ACA) receiving in vitro fertilization (IVF)-embryo transfer (ET) and natural conception. METHODS: A case-control study was used to retrospectively analyze the clinical data of 3955 patients who received IVF-ET therapy and had the results of antinuclear antibody (ANA) spectrum at Zhejiang Provincial People's Hospital from June 2016 to June 2023. Patients with positive ACA and negative ACA were matched at a ratio of 1â¶3 using propensity score matching. Embryo outcomes of IVF were compared between the two groups, and the impact of different fertilization methods and the use of immunosuppressants on pregnancy outcomes were analyzed using self-matching. The natural conception and disease progress were followed up for ACA-positive patients after IVF failure. RESULTS: The ACA-positive patients accounted for 0.86% of all IVF patients (34/3955) and 2.51% of total ANA-positive IVF patients. Regardless of whether patients received conventional IVF (c-IVF) or intracytoplasmic sperm injection (ICSI), the ACA-positive group exhibited significant differences in oocyte maturity and fertilization compared to the ACA-negative group (both P<0.01). Moreover, the ACA-positive group had a decreased number of D3 suboptimal embryos and D3 optimal embryos (both P<0.05). In 5 cases of ACA-positive patients who underwent ICSI cycles, the two pronucleus (2PN) rate did not increase compared to c-IVF cycles (P>0.05), and there was a decrease in the number of D3 high-quality embryos and D3 suboptimal embryos (both P<0.05). After 1-2 months of immuno-suppressant treatment, 12 ACA-positive patients underwent c-IVF/ICSI again, and there were no changes in egg retrieval and fertilization before and after medication (both P>0.05), but there was an improvement in the 2PN embryo cleavage rate (P<0.05). The number of embryos transferred was similar between the ACA-positive and negative groups, but the ACA-positive group had significantly lower embryo implantation rate and clinical pregnancy rate compared to the ACA-negative group (both P<0.05), with no significant differences in the miscarriage rate between the two groups (P>0.05). Twenty-seven ACA-positive patients attempted natural conception or artificial insemination after IVF failure, resulting in a total of 7 cases of clinical pregnancy. CONCLUSIONS: Serum ACA positivity may disrupt oocyte maturation and normal fertilization processes, with no improvement observed with ICSI and immunosuppressant use. However, ACA-positive patients may still achieve natural pregnancy.
Assuntos
Anticorpos Antinucleares , Transferência Embrionária , Fertilização in vitro , Resultado da Gravidez , Humanos , Feminino , Gravidez , Fertilização in vitro/métodos , Estudos Retrospectivos , Transferência Embrionária/métodos , Estudos de Casos e Controles , Adulto , Anticorpos Antinucleares/sangue , Injeções de Esperma Intracitoplásmicas , Taxa de GravidezRESUMO
Exosome-based liquid biopsies highlight potential utility in diagnosis and determining the prognosis of patients with cancer and other diseases. However, the existing techniques are severely limited for practical applications due to the complications of high cost, low sensitivity, tedious procedures, and large sample consumption. Herein, we report a microstructured optical fiber sensor for fast, sensitive, and accurate quantification of exosomes in blood samples of breast cancer patients. Numerical simulations are applied to demonstrate that hollow-core microstructured antiresonant fibers (HARFs) can stringently confine light in the fiber core, ensuring strong light-matter interaction and thus maximumly amplifying the signal. Taking this advantage, a AuNPs-dsDNA assembly containing gold nanoparticles, a recognizing DNA aptamer, and a fluorescent reporter DNA sequence is fabricated followed by immobilization on the fiber wall to form a AuNPs-dsDNA-HARF sensor. Cancer-derived exosomes can be recognized and captured in the fiber channel and generate dose-dependent fluorescent signals for quantification. The microfiber sensor demonstrates enhanced sensitivity and specificity, enabling the detection of single digits of exosome particles at the nanoliter sample level. In addition, by tracking exosome phenotypic changes, the proposed fiber sensor can facilitate precise drug treatment monitoring. This work provides a robust platform for exosome-based biopsy for cancer diagnosis and prediction of therapeutic outcomes.
Assuntos
Técnicas Biossensoriais , Neoplasias da Mama , Exossomos , Nanopartículas Metálicas , Humanos , Feminino , Fibras Ópticas , Ouro , Neoplasias da Mama/diagnóstico , Biópsia Líquida , Técnicas Biossensoriais/métodosRESUMO
MOTIVATION: Identifying cell types and their abundances and how these evolve during tumor progression is critical to understanding the mechanisms of metastasis and identifying predictors of metastatic potential that can guide the development of new diagnostics or therapeutics. Single-cell RNA sequencing (scRNA-seq) has been especially promising in resolving heterogeneity of expression programs at the single-cell level, but is not always feasible, e.g. for large cohort studies or longitudinal analysis of archived samples. In such cases, clonal subpopulations may still be inferred via genomic deconvolution, but deconvolution methods have limited ability to resolve fine clonal structure and may require reference cell type profiles that are missing or imprecise. Prior methods can eliminate the need for reference profiles but show unstable performance when few bulk samples are available. RESULTS: In this work, we develop a new method using reference scRNA-seq to interpret sample collections for which only bulk RNA-seq is available for some samples, e.g. clonally resolving archived primary tissues using scRNA-seq from metastases. By integrating such information in a Quadratic Programming framework, our method can recover more accurate cell types and corresponding cell type abundances in bulk samples. Application to a breast tumor bone metastases dataset confirms the power of scRNA-seq data to improve cell type inference and quantification in same-patient bulk samples. AVAILABILITY AND IMPLEMENTATION: Source code is available on Github at https://github.com/CMUSchwartzLab/RADs.