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1.
Fam Community Health ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38912691

RESUMO

BACKGROUND AND OBJECTIVES: Language-appropriate outcome measurements help to improve health equity. The purpose of this study was to translate and validate the Cohen-Hoberman Inventory of Physical Symptoms (CHIPS) in Nepali for Bhutanese refugee utilization. METHODS: English-Nepali forward and back translations of CHIPS were completed by an official translator and evaluated by three content experts. A scaled rubric measured the following constructs: neurogenic stress response (NSR), somatic stress response (SSR), and visceral stress response (VSR). Data were analyzed using SPSS 26.0. RESULTS: The Nepali version of CHIPS reported good content validity, strong internal consistency (Cronbach's α = .94), and inter-rater reliability (ICC = 0.91). Kappa statistic reported 88% to 96% agreement. Constructs of NSR (0.91), SSR (0.94), and VSR (0.94) reported strong internal consistency. CONCLUSIONS: The Nepali translated version of CHIPS showed strong validity and reliability for utilization in the Bhutanese refugee population and improves health access to outcome measurements for a vulnerable population.

2.
bioRxiv ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38915582

RESUMO

Single-particle tracking demonstrates that individual filaments in bundles of vimentin intermediate filaments are transported in the cytoplasm by motor proteins along microtubules. Furthermore, using 3D FIB-SEM the authors showed that vimentin filament bundles are loosely packed and coaligned with microtubules. Vimentin intermediate filaments (VIFs) form complex, tight-packed networks; due to this density, traditional ensemble labeling and imaging approaches cannot accurately discern single filament behavior. To address this, we introduce a sparse vimentin-SunTag labeling strategy to unambiguously visualize individual filament dynamics. This technique confirmed known long-range dynein and kinesin transport of peripheral VIFs and uncovered extensive bidirectional VIF motion within the perinuclear vimentin network, a region we had thought too densely bundled to permit such motility. To examine the nanoscale organization of perinuclear vimentin, we acquired high-resolution electron microscopy volumes of a vitreously frozen cell and reconstructed VIFs and microtubules within a ~50 µm3 window. Of 583 VIFs identified, most were integrated into long, semi-coherent bundles that fluctuated in width and filament packing density. Unexpectedly, VIFs displayed minimal local co-alignment with microtubules, save for sporadic cross-over sites that we predict facilitate cytoskeletal crosstalk. Overall, this work demonstrates single VIF dynamics and organization in the cellular milieu for the first time.

3.
bioRxiv ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38895210

RESUMO

Mitochondria-ER membrane contact sites (MERCS) represent a fundamental ultrastructural feature underlying unique biochemistry and physiology in eukaryotic cells. The ER protein PDZD8 is required for the formation of MERCS in many cell types, however, its tethering partner on the outer mitochondrial membrane (OMM) is currently unknown. Here we identified the OMM protein FKBP8 as the tethering partner of PDZD8 using a combination of unbiased proximity proteomics, CRISPR-Cas9 endogenous protein tagging, Cryo-Electron Microscopy (Cryo-EM) tomography, and correlative light-EM (CLEM). Single molecule tracking revealed highly dynamic diffusion properties of PDZD8 along the ER membrane with significant pauses and capture at MERCS. Overexpression of FKBP8 was sufficient to narrow the ER-OMM distance, whereas independent versus combined deletions of these two proteins demonstrated their interdependence for MERCS formation. Furthermore, PDZD8 enhances mitochondrial complexity in a FKBP8-dependent manner. Our results identify a novel ER-mitochondria tethering complex that regulates mitochondrial morphology in mammalian cells.

4.
Proc Natl Acad Sci U S A ; 121(23): e2308531121, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38805288

RESUMO

Many animals exhibit remarkable colors that are produced by the constructive interference of light reflected from arrays of intracellular guanine crystals. These animals can fine-tune their crystal-based structural colors to communicate with each other, regulate body temperature, and create camouflage. While it is known that these changes in color are caused by changes in the angle of the crystal arrays relative to incident light, the cellular machinery that drives color change is not understood. Here, using a combination of 3D focused ion beam scanning electron microscopy (FIB-SEM), micro-focused X-ray diffraction, superresolution fluorescence light microscopy, and pharmacological perturbations, we characterized the dynamics and 3D cellular reorganization of crystal arrays within zebrafish iridophores during norepinephrine (NE)-induced color change. We found that color change results from a coordinated 20° tilting of the intracellular crystals, which alters both crystal packing and the angle at which impinging light hits the crystals. Importantly, addition of the dynein inhibitor dynapyrazole-a completely blocked this NE-induced red shift by hindering crystal dynamics upon NE addition. FIB-SEM and microtubule organizing center (MTOC) mapping showed that microtubules arise from two MTOCs located near the poles of the iridophore and run parallel to, and in between, individual crystals. This suggests that dynein drives crystal angle change in response to NE by binding to the limiting membrane surrounding individual crystals and walking toward microtubule minus ends. Finally, we found that intracellular cAMP regulates the color change process. Together, our results provide mechanistic insight into the cellular machinery that drives structural color change.


Assuntos
Peixe-Zebra , Animais , Norepinefrina/metabolismo , Norepinefrina/farmacologia , Cor , Pigmentação/fisiologia , Microscopia Eletrônica de Varredura , Proteínas de Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/química
5.
Curr Biol ; 34(11): 2418-2433.e4, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38749425

RESUMO

A primary cilium is a membrane-bound extension from the cell surface that contains receptors for perceiving and transmitting signals that modulate cell state and activity. Primary cilia in the brain are less accessible than cilia on cultured cells or epithelial tissues because in the brain they protrude into a deep, dense network of glial and neuronal processes. Here, we investigated cilia frequency, internal structure, shape, and position in large, high-resolution transmission electron microscopy volumes of mouse primary visual cortex. Cilia extended from the cell bodies of nearly all excitatory and inhibitory neurons, astrocytes, and oligodendrocyte precursor cells (OPCs) but were absent from oligodendrocytes and microglia. Ultrastructural comparisons revealed that the base of the cilium and the microtubule organization differed between neurons and glia. Investigating cilia-proximal features revealed that many cilia were directly adjacent to synapses, suggesting that cilia are poised to encounter locally released signaling molecules. Our analysis indicated that synapse proximity is likely due to random encounters in the neuropil, with no evidence that cilia modulate synapse activity as would be expected in tetrapartite synapses. The observed cell class differences in proximity to synapses were largely due to differences in external cilia length. Many key structural features that differed between neuronal and glial cilia influenced both cilium placement and shape and, thus, exposure to processes and synapses outside the cilium. Together, the ultrastructure both within and around neuronal and glial cilia suggest differences in cilia formation and function across cell types in the brain.


Assuntos
Cílios , Animais , Cílios/ultraestrutura , Camundongos , Microscopia Eletrônica de Transmissão , Camundongos Endogâmicos C57BL , Neurônios/ultraestrutura , Neurônios/fisiologia , Córtex Visual/ultraestrutura , Córtex Visual/fisiologia , Neuroglia/ultraestrutura , Neuroglia/fisiologia , Feminino , Sinapses/ultraestrutura , Sinapses/fisiologia , Masculino
7.
Am Soc Clin Oncol Educ Book ; 44(3): e100046, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38776483

RESUMO

A community of practice (CoP) is a group of people who share a concern or a passion for something they do and learn how to do it better as they interact regularly. While the field of hematology/oncology has historically prioritized clinical care and biomedical research, medical education has received increasing attention within hematology/oncology in recent years. In 2018, ASCO launched the Education Scholars Program to train hematology/oncology clinicians in the science of teaching and learning. However, the number of hematology/oncology educators nationally and internationally far exceeds the capacity of the Education Scholars Program to train them. In addition, hematology/oncology educators often lack sufficient mentorship and guidance at their own institutions to pursue their chosen career path effectively. To ensure high-quality clinical care and research for generations to come, attention must be paid to improving support for hematology/oncology educators. Therefore, supported by ASCO, we developed an international medical education (Med Ed) CoP for hematology/oncology educators with the purpose of providing them with support, community, mentorship, resources, and scholarly opportunities in medical education. In this article, we describe the development of the Med Ed CoP using a three-stage framework (Establish-Grow-Sustain) including successes, challenges, and reflections. By supporting the needs of hematology/oncology educators, the Med Ed CoP will serve as a home for all who contribute to the field of hematology/oncology.


Assuntos
Educação Médica , Hematologia , Oncologia , Humanos , Oncologia/educação , Hematologia/educação , Mentores , Comunidade de Prática
8.
iScience ; 27(6): 109927, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38784009

RESUMO

YAP/TEAD signaling is essential for organismal development, cell proliferation, and cancer progression. As a transcriptional coactivator, how YAP activates its downstream target genes is incompletely understood. YAP forms biomolecular condensates in response to hyperosmotic stress, concentrating transcription-related factors to activate downstream target genes. However, whether YAP forms condensates under other signals, how YAP condensates organize and function, and how YAP condensates activate transcription in general are unknown. Here, we report that endogenous YAP forms sub-micron scale condensates in response to Hippo pathway regulation and actin cytoskeletal tension. YAP condensates are stabilized by the transcription factor TEAD1, and recruit BRD4, a coactivator that is enriched at active enhancers. Using single-particle tracking, we found that YAP condensates slowed YAP diffusion within condensate boundaries, a possible mechanism for promoting YAP target search. These results reveal that YAP condensate formation is a highly regulated process that is critical for YAP/TEAD target gene expression.

9.
Dev Cell ; 59(11): 1410-1424.e4, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38593803

RESUMO

Endoplasmic reticulum exit sites (ERESs) are tubular outgrowths of endoplasmic reticulum that serve as the earliest station for protein sorting and export into the secretory pathway. How these structures respond to different cellular conditions remains unclear. Here, we report that ERESs undergo lysosome-dependent microautophagy when Ca2+ is released by lysosomes in response to nutrient stressors such as mTOR inhibition or amino acid starvation in mammalian cells. Targeting and uptake of ERESs into lysosomes were observed by super-resolution live-cell imaging and focus ion beam scanning electron microscopy (FIB-SEM). The mechanism was ESCRT dependent and required ubiquitinated SEC31, ALG2, and ALIX, with a knockout of ALG2 or function-blocking mutations of ALIX preventing engulfment of ERESs by lysosomes. In vitro, reconstitution of the pathway was possible using lysosomal lipid-mimicking giant unilamellar vesicles and purified recombinant components. Together, these findings demonstrate a pathway of lysosome-dependent ERES microautophagy mediated by COPII, ALG2, and ESCRTS induced by nutrient stress.


Assuntos
Vesículas Revestidas pelo Complexo de Proteína do Envoltório , Proteínas de Ligação ao Cálcio , Retículo Endoplasmático , Complexos Endossomais de Distribuição Requeridos para Transporte , Lisossomos , Microautofagia , Proteínas de Transporte Vesicular , Lisossomos/metabolismo , Retículo Endoplasmático/metabolismo , Humanos , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Transporte Proteico , Células HeLa , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/genética , Autofagia/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Cálcio/metabolismo
10.
Mol Biol Cell ; 35(4): ar51, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38381564

RESUMO

Visualization of specific molecules and their assembly in real time and space is essential to delineate how cellular dynamics and signaling circuit are orchestrated during cell division cycle. Our recent studies reveal structural insights into human centromere-kinetochore core CCAN complex. Here we introduce a method for optically imaging trimeric and tetrameric protein interactions at nanometer spatial resolution in live cells using fluorescence complementation-based Förster resonance energy transfer (FC-FRET). Complementary fluorescent protein molecules were first used to visualize dimerization followed by FRET measurements. Using FC-FRET, we visualized centromere CENP-SXTW tetramer assembly dynamics in live cells, and dimeric interactions between CENP-TW dimer and kinetochore protein Spc24/25 dimer in dividing cells. We further delineated the interactions of monomeric CENP-T with Spc24/25 dimer in dividing cells. Surprisingly, our analyses revealed critical role of CDK1 kinase activity in the initial recruitment of Spc24/25 by CENP-T. However, interactions between CENP-T and Spc24/25 during chromosome segregation is independent of CDK1. Thus, FC-FRET provides a unique approach to delineate spatiotemporal dynamics of trimerized and tetramerized proteins at nanometer scale and establishes a platform to report the precise regulation of multimeric protein interactions in space and time in live cells.


Assuntos
Proteínas Cromossômicas não Histona , Transferência Ressonante de Energia de Fluorescência , Humanos , Proteínas Cromossômicas não Histona/metabolismo , Cinetocoros/metabolismo , Ciclo Celular , Centrômero/metabolismo , Proteína Centromérica A/metabolismo
11.
iScience ; 27(3): 109107, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38384847

RESUMO

Most mammalian cells prevent viral infection and proliferation by expressing various restriction factors and sensors that activate the immune system. Several host restriction factors that inhibit human immunodeficiency virus type 1 (HIV-1) have been identified, but most of them are antagonized by viral proteins. Here, we describe CCHC-type zinc-finger-containing protein 3 (ZCCHC3) as a novel HIV-1 restriction factor that suppresses the production of HIV-1 and other retroviruses, but does not appear to be directly antagonized by viral proteins. It acts by binding to Gag nucleocapsid (GagNC) via zinc-finger motifs, which inhibits viral genome recruitment and results in genome-deficient virion production. ZCCHC3 also binds to the long terminal repeat on the viral genome via the middle-folded domain, sequestering the viral genome to P-bodies, which leads to decreased viral replication and production. This distinct, dual-acting antiviral mechanism makes upregulation of ZCCHC3 a novel potential therapeutic strategy.

12.
J Mol Cell Biol ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38389254

RESUMO

Although the dynamic instability of microtubules (MTs) is fundamental to many cellular functions, quiescent MTs with unattached free distal ends are commonly present and play important roles in various events to power cellular dynamics. However, how these free MT tips are stabilized remains poorly understood. Here, we report that centrosome and spindle pole protein 1 (CSPP1) caps and stabilizes both plus and minus ends of static MTs. Real-time imaging of laser-ablated MTs in live cells showed deposition of CSPP1 at the newly generated MT ends, whose dynamic instability was concomitantly suppressed. Consistently, MT ends in CSPP1-overexpressing cells were hyper-stabilized, while those in CSPP1-depleted cells were much more dynamic. This CSPP1-elicited stabilization of MTs was demonstrated to be achieved by suppressing intrinsic MT catastrophe and restricting the polymerization. Importantly, CSPP1-bound MTs were resistant to MCAK-mediated depolymerization. These findings delineate a previously uncharacterized CSPP1 activity that integrates MT end capping to orchestrate quiescent MTs.

13.
bioRxiv ; 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38293171

RESUMO

Yersinia pestis , one of the deadliest bacterial pathogens ever known, is responsible for three plague pandemics and several epidemics, with over 200 million deaths during recorded history. Due to high genomic plasticity, Y. pestis is amenable to genetic mutations as well as genetic engineering that can lead to the emergence or intentional development of pan-drug resistant strains. The dissemination of such Y. pestis strains could be catastrophic, with public health consequences far more daunting than those caused by the recent COVID-19 pandemic. Thus, there is an urgent need to develop novel, safe, and effective treatment approaches for managing Y. pestis infections. This includes infections by antigenically distinct strains for which vaccines, none FDA approved yet, may not be effective, and those that cannot be controlled by approved antibiotics. Lytic bacteriophages provide one such alternative approach. In this study, we examined post-exposure efficacy of a bacteriophage cocktail, YPP-401, to combat pneumonic plague caused by Y. pestis CO92. YPP-401 is a four-phage preparation with a 100% lytic activity against a panel of 68 genetically diverse Y. pestis strains. Using a pneumonic plague aerosol challenge model in gender-balanced Brown Norway rats, YPP-401 demonstrated ∼88% protection when delivered 18 hours post-exposure for each of two administration routes (i.e., intraperitoneal and intranasal) in a dose-dependent manner. Our studies suggest that YPP-401 could provide an innovative, safe, and effective approach for managing Y. pestis infections, including those caused by naturally occurring or intentionally developed strains that cannot be managed by vaccines in development and antibiotics.

14.
Obes Surg ; 34(2): 337-346, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38170422

RESUMO

BACKGROUND: Rapid adoption of sleeve gastrectomy (SG) in the last decade aptly reflects the desire of patients and surgeons for alternatives to RYGB and DS. While SG provides good outcomes, other options that address specific patient needs are warranted. Recently approved by ASMBS, SADI, and OAGB have garnered increasing interest due to their single anastomosis technique. METHODS: Using the Metabolic and Bariatric Surgery Quality Improvement Program database, we examined laparoscopic and robotic cases from 2018 to 2021 to understand the percentage of primary bariatric surgery cases that are SADI and OAGB. We used coarsened exact matching to match patients who underwent SADI or OAGB to patients who underwent Roux-en-Y gastric bypass (RYGB). We examined outcomes of matched patients using logistic regression. RESULTS: Of the 667,979 patients that underwent bariatric-metabolic surgery, 1326 (0.2%) underwent SADI, and 2541 (0.4%) underwent OAGB. SADI was not identified in the database until 2020. In 2020, there were 487 SADI procedures compared to 839 in 2021. From 2018 to 2021, OAGBs went from 149 to 940. Compared with RYGB, SADI was associated with higher rates of anastomotic or staple line leak (OR 2.21 (95% CI 1.08-4.53)) and sepsis (OR 3.62 (95% CI 1.62-8.12)). Compared with RYGB, OAGB was associated with lower rates of gastrointestinal bleeding (OR 0.29 (95% CI 0.12-0.71)) and bowel obstruction (OR 0.10 (95% CI 0.02-0.39)). Of note, there were no differences between these procedures and RYGB for 30-day mortality. CONCLUSION: More SADIs and OAGBs are being performed. However, there were higher complication rates associated with the SADI procedure. Further studies will be needed to better understand the key drivers for these outcomes.


Assuntos
Cirurgia Bariátrica , Derivação Gástrica , Obesidade Mórbida , Humanos , Derivação Gástrica/métodos , Obesidade Mórbida/cirurgia , Melhoria de Qualidade , Gastrectomia/métodos , América do Norte/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento
15.
Nature ; 626(7997): 169-176, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38267577

RESUMO

To coordinate cellular physiology, eukaryotic cells rely on the rapid exchange of molecules at specialized organelle-organelle contact sites1,2. Endoplasmic reticulum-mitochondrial contact sites (ERMCSs) are particularly vital communication hubs, playing key roles in the exchange of signalling molecules, lipids and metabolites3,4. ERMCSs are maintained by interactions between complementary tethering molecules on the surface of each organelle5,6. However, due to the extreme sensitivity of these membrane interfaces to experimental perturbation7,8, a clear understanding of their nanoscale organization and regulation is still lacking. Here we combine three-dimensional electron microscopy with high-speed molecular tracking of a model organelle tether, Vesicle-associated membrane protein (VAMP)-associated protein B (VAPB), to map the structure and diffusion landscape of ERMCSs. We uncovered dynamic subdomains within VAPB contact sites that correlate with ER membrane curvature and undergo rapid remodelling. We show that VAPB molecules enter and leave ERMCSs within seconds, despite the contact site itself remaining stable over much longer time scales. This metastability allows ERMCSs to remodel with changes in the physiological environment to accommodate metabolic needs of the cell. An amyotrophic lateral sclerosis-associated mutation in VAPB perturbs these subdomains, likely impairing their remodelling capacity and resulting in impaired interorganelle communication. These results establish high-speed single-molecule imaging as a new tool for mapping the structure of contact site interfaces and reveal that the diffusion landscape of VAPB at contact sites is a crucial component of ERMCS homeostasis.


Assuntos
Retículo Endoplasmático , Mitocôndrias , Membranas Mitocondriais , Movimento , Proteínas de Transporte Vesicular , Humanos , Esclerose Lateral Amiotrófica/genética , Retículo Endoplasmático/química , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Mitocôndrias/química , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Membranas Mitocondriais/química , Membranas Mitocondriais/metabolismo , Membranas Mitocondriais/ultraestrutura , Transdução de Sinais , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Proteínas de Transporte Vesicular/ultraestrutura , Microscopia Eletrônica , Imageamento Tridimensional , Sítios de Ligação , Difusão , Fatores de Tempo , Mutação , Homeostase
16.
Obes Surg ; 34(1): 51-70, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37994997

RESUMO

BACKGROUND: The incidence and impact of hypoalbuminemia in bariatric surgery patients is poorly characterized. We describe its distribution in laparoscopic sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB) patients undergoing primary or revision surgeries and assess its impact on postoperative complications. METHODS: The Metabolic and Bariatric Surgery Quality Improvement Program Database (2015 to 2021) was analyzed. Hypoalbuminemia was defined as Severe (< 3 g/dL), Moderate (3 ≤ 3.5 g/dL), Mild (3.5 ≤ 4 g/dL), or Normal (≥ 4 g/dL). Multivariable logistic regression was performed to calculate odds ratios of postoperative complications compared to those with Normal albumin after controlling for procedure, age, gender, race, body mass index, functional status, American Society of Anesthesia class, and operative length. RESULTS: A total of 817,310 patients undergoing Primary surgery and 69,938 patients undergoing Revision/Conversion ("Revision") surgery were analyzed. The prevalence of hypoalbuminemia was as follows (Primary, Revision): Severe, 0.3%, 0.6%; Moderate, 5.2%, 6.5%; Mild, 28.3%, 31.4%; Normal, 66.2%, 61.4%. Primary and Revision patients with hypoalbuminemia had a significantly higher prevalence (p < 0.01) of several co-morbidities, including hypertension and insulin-dependent diabetes. Any degree of hypoalbuminemia increased the odds ratio of several complications in Primary and Revision patients, including readmission, intervention, and reoperation. In Primary patients, all levels of hypoalbuminemia also increased the odds ratio of unplanned intubation, intensive care unit admission, and venous thromboembolism requiring therapy. CONCLUSION: Over 30% of patients present with hypoalbuminemia. Even mild hypoalbuminemia was associated with an increased rate of several complications including readmission, intervention, and reoperation. Ensuring nutritional optimization, especially prior to revision surgery, may improve outcomes in this challenging population.


Assuntos
Cirurgia Bariátrica , Derivação Gástrica , Hipoalbuminemia , Obesidade Mórbida , Humanos , Hipoalbuminemia/epidemiologia , Hipoalbuminemia/etiologia , Obesidade Mórbida/cirurgia , Cirurgia Bariátrica/efeitos adversos , Cirurgia Bariátrica/métodos , Complicações Pós-Operatórias/etiologia , Derivação Gástrica/métodos , Gastrectomia/efeitos adversos , Gastrectomia/métodos , Estudos Retrospectivos , Resultado do Tratamento
17.
bioRxiv ; 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38106104

RESUMO

Primary cilia on granule cell neuron progenitors in the developing cerebellum detect sonic hedgehog to facilitate proliferation. Following differentiation, cerebellar granule cells become the most abundant neuronal cell type in the brain. While essential during early developmental stages, the fate of granule cell cilia is unknown. Here, we provide nanoscopic resolution of ciliary dynamics in situ by studying developmental changes in granule cell cilia using large-scale electron microscopy volumes and immunostaining of mouse cerebella. We found that many granule cell primary cilia were intracellular and concealed from the external environment. Cilia were disassembed in differentiating granule cell neurons in a process we call cilia deconstruction that was distinct from pre-mitotic cilia resorption in proliferating progenitors. In differentiating granule cells, ciliary loss involved unique disassembly intermediates, and, as maturation progressed, mother centriolar docking at the plasma membrane. Cilia did not reform from the docked centrioles, rather, in adult mice granule cell neurons remained unciliated. Many neurons in other brain regions require cilia to regulate function and connectivity. In contrast, our results show that granule cell progenitors had concealed cilia that underwent deconstruction potentially to prevent mitogenic hedgehog responsiveness. The ciliary deconstruction mechanism we describe could be paradigmatic of cilia removal during differentiation in other tissues.

18.
bioRxiv ; 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37961618

RESUMO

A primary cilium is a thin membrane-bound extension off a cell surface that contains receptors for perceiving and transmitting signals that modulate cell state and activity. While many cell types have a primary cilium, little is known about primary cilia in the brain, where they are less accessible than cilia on cultured cells or epithelial tissues and protrude from cell bodies into a deep, dense network of glial and neuronal processes. Here, we investigated cilia frequency, internal structure, shape, and position in large, high-resolution transmission electron microscopy volumes of mouse primary visual cortex. Cilia extended from the cell bodies of nearly all excitatory and inhibitory neurons, astrocytes, and oligodendrocyte precursor cells (OPCs), but were absent from oligodendrocytes and microglia. Structural comparisons revealed that the membrane structure at the base of the cilium and the microtubule organization differed between neurons and glia. OPC cilia were distinct in that they were the shortest and contained pervasive internal vesicles only occasionally observed in neuron and astrocyte cilia. Investigating cilia-proximal features revealed that many cilia were directly adjacent to synapses, suggesting cilia are well poised to encounter locally released signaling molecules. Cilia proximity to synapses was random, not enriched, in the synapse-rich neuropil. The internal anatomy, including microtubule changes and centriole location, defined key structural features including cilium placement and shape. Together, the anatomical insights both within and around neuron and glia cilia provide new insights into cilia formation and function across cell types in the brain.

19.
EMBO J ; 42(24): e114054, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37933600

RESUMO

Cristae are high-curvature structures in the inner mitochondrial membrane (IMM) that are crucial for ATP production. While cristae-shaping proteins have been defined, analogous lipid-based mechanisms have yet to be elucidated. Here, we combine experimental lipidome dissection with multi-scale modeling to investigate how lipid interactions dictate IMM morphology and ATP generation. When modulating phospholipid (PL) saturation in engineered yeast strains, we observed a surprisingly abrupt breakpoint in IMM topology driven by a continuous loss of ATP synthase organization at cristae ridges. We found that cardiolipin (CL) specifically buffers the inner mitochondrial membrane against curvature loss, an effect that is independent of ATP synthase dimerization. To explain this interaction, we developed a continuum model for cristae tubule formation that integrates both lipid and protein-mediated curvatures. This model highlighted a snapthrough instability, which drives IMM collapse upon small changes in membrane properties. We also showed that cardiolipin is essential in low-oxygen conditions that promote PL saturation. These results demonstrate that the mechanical function of cardiolipin is dependent on the surrounding lipid and protein components of the IMM.


Assuntos
Cardiolipinas , Lipidômica , Cardiolipinas/metabolismo , Membranas Mitocondriais/metabolismo , Fosfolipídeos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Trifosfato de Adenosina/metabolismo
20.
J Nucl Med ; 64(11): 1721-1725, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37770113

RESUMO

177Lu-PSMA-617 and 177Lu-PSMA I&T (collectively termed 177Lu-PSMA) are currently being used for the treatment of selected metastatic castration-resistant prostate cancer (mCRPC) patients with PSMA PET-positive disease, but biomarkers for these agents remain incompletely understood. Methods: Pretreatment circulating tumor DNA (ctDNA) samples were collected from 44 mCRPC patients receiving 177Lu-PSMA treatment. Prostate-specific antigen responders and nonresponders were assessed relative to the ctDNA findings at baseline. Results: The ctDNA findings indicated that nonresponders were more likely to have gene amplifications than were responders (75% vs. 39.2%, P = 0.03). In particular, amplifications in FGFR1 (25% vs. 0%, P = 0.01) and CCNE1 (31.2% vs. 0%, P = 0.001) were more likely to be present in nonresponders. CDK12 mutations were more likely to be present in nonresponders (25% vs. 3.6%, P = 0.05). Conclusion: Our analyses indicate that ctDNA assays may contain specific biomarkers predictive of response or resistance for 177Lu-PSMA-treated mCRPC patients. Additional confirmatory studies are required before clinicians can use these findings to make personalized treatment decisions.


Assuntos
DNA Tumoral Circulante , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , DNA Tumoral Circulante/genética , Compostos Radiofarmacêuticos/efeitos adversos , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/radioterapia , Antígeno Prostático Específico , Dipeptídeos/efeitos adversos , Compostos Heterocíclicos com 1 Anel/efeitos adversos , Lutécio/uso terapêutico , Resultado do Tratamento , Estudos Retrospectivos
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