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1.
JMIR Hum Factors ; 11: e57239, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861717

RESUMO

BACKGROUND: Overdose Fatality Review (OFR) is an important public health tool for shaping overdose prevention strategies in communities. However, OFR teams review only a few cases at a time, which typically represent a small fraction of the total fatalities in their jurisdiction. Such limited review could result in a partial understanding of local overdose patterns, leading to policy recommendations that do not fully address the broader community needs. OBJECTIVE: This study explored the potential to enhance conventional OFRs with a data dashboard, incorporating visualizations of touchpoints-events that precede overdoses-to highlight prevention opportunities. METHODS: We conducted 2 focus groups and a survey of OFR experts to characterize their information needs and design a real-time dashboard that tracks and measures decedents' past interactions with services in Indiana. Experts (N=27) were engaged, yielding insights on essential data features to incorporate and providing feedback to guide the development of visualizations. RESULTS: The findings highlighted the importance of showing decedents' interactions with health services (emergency medical services) and the justice system (incarcerations). Emphasis was also placed on maintaining decedent anonymity, particularly in small communities, and the need for training OFR members in data interpretation. The developed dashboard summarizes key touchpoint metrics, including prevalence, interaction frequency, and time intervals between touchpoints and overdoses, with data viewable at the county and state levels. In an initial evaluation, the dashboard was well received for its comprehensive data coverage and its potential for enhancing OFR recommendations and case selection. CONCLUSIONS: The Indiana touchpoints dashboard is the first to display real-time visualizations that link administrative and overdose mortality data across the state. This resource equips local health officials and OFRs with timely, quantitative, and spatiotemporal insights into overdose risk factors in their communities, facilitating data-driven interventions and policy changes. However, fully integrating the dashboard into OFR practices will likely require training teams in data interpretation and decision-making.


Assuntos
Overdose de Drogas , Grupos Focais , Design Centrado no Usuário , Humanos , Overdose de Drogas/prevenção & controle , Overdose de Drogas/epidemiologia , Indiana/epidemiologia , Inquéritos e Questionários
2.
J Equine Vet Sci ; : 105143, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38945460

RESUMO

Periods of limited activity during semester break may reduce performance during return to ridden work. This study evaluated fitness and muscling of horses when returning to work, following a 12-week period during which horses either continued (conditioned) or discontinued (non-conditioned) ridden work. It was hypothesized that non-conditioned horses would have a lower level of fitness, resulting in higher resting and peak heart rates and lower levels of muscling. Twelve mature, stock type horses aged 16 ± 5 years were assigned to either a conditioned group that maintained light-to-moderate riding or a non-conditioned group receiving no formal exercise. All horses had access to voluntary exercise for 12-24hr/d on grass pasture (1.5-2.5 hectares). Following the 12-week period, all horses were placed into a light-to-moderate intensity exercise program with resting heart rate, peak heart rate, body condition score, gaskin and forearm circumference, and topline muscle measurements performed on d 0, 14, and 28. Peak and resting heart rates were not different between groups (P > 0.05) but increased for both groups throughout the study (P = 0.04). Gaskin circumference of non-conditioned horses was larger (P = 0.04), although non-conditioned horses tended to be heavier (551.4 versus 491.4 ± 21.4 kg; P = 0.07). Conditioned horses had greater average topline muscling scores (P = 0.02). Horses that were conditioned over a 12-week break had greater muscling, but changes in fitness were not detected. Pasture access could contribute to maintenance of fitness during unridden periods.

3.
bioRxiv ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38895306

RESUMO

How can a single protein domain encode a conformational landscape with multiple stably-folded states, and how do those states interconvert? Here, we use real-time and relaxation-dispersion NMR to characterize the conformational landscape of the circadian rhythm protein KaiB from Rhodobacter sphaeroides. Unique among known natural metamorphic proteins, this KaiB variant spontaneously interconverts between two monomeric states: the "Ground" and "Fold-switched" (FS) state. KaiB in its FS state interacts with multiple binding partners, including the central KaiC protein, to regulate circadian rhythms. We find that KaiB itself takes hours to interconvert between the Ground and FS state, underscoring the ability of a single sequence to encode the slow process needed for function. We reveal the rate-limiting step between the Ground and FS state is the cis-trans isomerization of three prolines in the fold-switching region by demonstrating interconversion acceleration by the prolyl isomerase CypA. The interconversion proceeds through a "partially disordered" (PD) state, where the C-terminal half becomes disordered while the N-terminal half remains stably folded. We discovered two additional properties of KaiB's landscape. Firstly, the Ground state experiences cold denaturation: at 4°C, the PD state becomes the majorly populated state. Secondly, the Ground state exchanges with a fourth state, the "Enigma" state, on the millisecond timescale. We combine AlphaFold2-based predictions and NMR chemical shift predictions to predict this "Enigma" state is a beta-strand register shift that eases buried charged residues, and support this structure experimentally. These results provide mechanistic insight in how evolution can design a single sequence that achieves specific timing needed for its function.

4.
Phys Rev X ; 14(1)2024.
Artigo em Inglês | MEDLINE | ID: mdl-38911939

RESUMO

The spiking activity of neocortical neurons exhibits a striking level of variability, even when these networks are driven by identical stimuli. The approximately Poisson firing of neurons has led to the hypothesis that these neural networks operate in the asynchronous state. In the asynchronous state, neurons fire independently from one another, so that the probability that a neuron experience synchronous synaptic inputs is exceedingly low. While the models of asynchronous neurons lead to observed spiking variability, it is not clear whether the asynchronous state can also account for the level of subthreshold membrane potential variability. We propose a new analytical framework to rigorously quantify the subthreshold variability of a single conductance-based neuron in response to synaptic inputs with prescribed degrees of synchrony. Technically, we leverage the theory of exchangeability to model input synchrony via jump-process-based synaptic drives; we then perform a moment analysis of the stationary response of a neuronal model with all-or-none conductances that neglects postspiking reset. As a result, we produce exact, interpretable closed forms for the first two stationary moments of the membrane voltage, with explicit dependence on the input synaptic numbers, strengths, and synchrony. For biophysically relevant parameters, we find that the asynchronous regime yields realistic subthreshold variability (voltage variance ≃4-9 mV2) only when driven by a restricted number of large synapses, compatible with strong thalamic drive. By contrast, we find that achieving realistic subthreshold variability with dense cortico-cortical inputs requires including weak but nonzero input synchrony, consistent with measured pairwise spiking correlations. We also show that, without synchrony, the neural variability averages out to zero for all scaling limits with vanishing synaptic weights, independent of any balanced state hypothesis. This result challenges the theoretical basis for mean-field theories of the asynchronous state.

5.
Cureus ; 16(4): e59354, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38817486

RESUMO

Gelatinous transformation of bone marrow (GTBM) is a rare hematologic condition in which hematopoietic cells in the bone marrow are replaced by extracellular gelatinous substances, often resulting in cytopenias. The true incidence of this condition is presently unknown, as the current body of literature primarily consists of case reports. However, an analysis of a large bone marrow registry suggests that this is a highly rare entity even among a population requiring bone marrow biopsy. We present a case of a 24-year-old man with a history of diffuse large B cell lymphoma and an associated 45-kilogram weight loss, who was later found to have GTBM. The extent of his cytopenias resulted in a prolonged hospitalization with numerous complications, eventually leading to experimental treatment with allogeneic stem cell transplantation (ASCT). To our knowledge, this is the first reported case of GTBM in which ASCT was employed as a potential treatment modality. While our patient did have clinical improvement following ASCT, the permanence of these results is presently unclear. Furthermore, it is uncertain if the ASCT was truly causative of the stabilization of the patient. Given this, we are currently unable to advocate for ASCT as a treatment for GTBM. We report this case to raise awareness of this rare entity in the context of refractory cytopenias.

6.
Respir Physiol Neurobiol ; 326: 104282, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38782084

RESUMO

Duchenne muscular dystrophy (DMD) is the most common X-linked disease. DMD is caused by a lack of dystrophin, a critical structural protein in striated muscle. Dystrophin deficiency leads to inflammation, fibrosis, and muscle atrophy. Boys with DMD have progressive muscle weakness within the diaphragm that results in respiratory failure in the 2nd or 3rd decade of life. The most common DMD mouse model - the mdx mouse - is not sufficient for evaluating genetic medicines that specifically target the human DMD (hDMD) gene sequence. Therefore, a novel transgenic mouse carrying the hDMD gene with an exon 52 deletion was created (hDMDΔ52;mdx). We characterized the respiratory function and pathology in this model using whole body plethysmography, histology, and immunohistochemistry. At 6-months-old, hDMDΔ52;mdx mice have reduced maximal respiration, neuromuscular junction pathology, and fibrosis throughout the diaphragm, which worsens at 12-months-old. In conclusion, the hDMDΔ52;mdx exhibits moderate respiratory pathology, and serves as a relevant animal model to study the impact of novel genetic therapies, including gene editing, on respiratory function.


Assuntos
Modelos Animais de Doenças , Camundongos Transgênicos , Distrofia Muscular de Duchenne , Animais , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patologia , Distrofia Muscular de Duchenne/fisiopatologia , Camundongos , Humanos , Masculino , Distrofina/genética , Distrofina/deficiência , Camundongos Endogâmicos mdx , Diafragma/fisiopatologia , Diafragma/patologia , Insuficiência Respiratória/etiologia , Junção Neuromuscular/patologia , Junção Neuromuscular/metabolismo , Camundongos Endogâmicos C57BL
7.
Oncogene ; 43(26): 2015-2024, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38744952

RESUMO

Somatic copy number alterations (SCNAs) are prevalent in cancer and play a significant role in both tumorigenesis and therapeutic resistance. While focal SCNAs have been extensively studied, the impact of larger arm-level SCNAs remains poorly understood. Here, we investigated the association between arm-level SCNAs and overall survival in triple-negative breast cancer (TNBC), an aggressive subtype of breast cancer lacking targeted therapies. We identified frequent arm-level SCNAs, including 21q gain and 7p gain, which correlated with poor overall survival in TNBC patients. Further, we identified the expression of specific genes within these SCNAs associated with survival. Notably, we found that the expression of RIPK4, a gene located on 21q, exhibited a strong correlation with poor overall survival. In functional assays, we demonstrated that targeting Ripk4 in a murine lung metastatic TNBC model significantly reduced tumor burden, improved survival, and increased CD4+ and CD8+ T cell infiltration. RIPK4 enhanced the survival of triple-negative breast cancer cells at secondary sites, thereby facilitating the formation of metastatic lesions. Our findings highlight the significance of arm-level SCNAs in breast cancer progression and identify RIPK4 as a putative driver of TNBC metastasis and immunosuppression.


Assuntos
Variações do Número de Cópias de DNA , Neoplasias de Mama Triplo Negativas , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/mortalidade , Humanos , Feminino , Animais , Prognóstico , Camundongos , Linhagem Celular Tumoral , Proteínas Serina-Treonina Quinases/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/mortalidade
8.
Psychiatr Psychol Law ; 31(2): 161-178, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38628246

RESUMO

One reason people are motivated to hold right-wing authoritarian beliefs is the need to manage uncertainty. Right-wing authoritarianism provides a stable source of black-and-white 'answers' about the social world - obey established authorities and norms and show hostility to deviants. Right-wing authoritarianism, in turn, is positively associated with more punitive attitudes and judgements. The purpose of this study was to examine the relationship between mock capital jurors' need for cognitive closure and sentencing decisions through right-wing authoritarianism. Four-hundred and fifty-one jury-eligible adults read a hypothetical capital case, weighed aggravating and mitigating evidence and chose a sentence. They also responded to items measuring right-wing authoritarianism and the need for cognitive closure. The need for cognitive closure was indirectly related to choosing a death sentence through right-wing authoritarianism and the weighing of aggravators and mitigators. Theoretical and practical implications, as well as directions for future studies, are discussed.

9.
Arthritis Res Ther ; 26(1): 73, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509602

RESUMO

BACKGROUND: Pain from osteoarthritis (OA) is one of the top causes of disability worldwide, but effective treatment is lacking. Nociceptive factors are released by activated synovial macrophages in OA, but depletion of synovial macrophages paradoxically worsens inflammation and tissue damage in previous studies. Rather than depleting macrophages, we hypothesized that inhibiting macrophage activation may improve pain without increasing tissue damage. We aimed to identify key mechanisms mediating synovial macrophage activation and test the role of STAT signaling in macrophages on pain outcomes in experimental knee OA. METHODS: We induced experimental knee OA in rats via knee destabilization surgery, and performed RNA sequencing analysis on sorted synovial tissue macrophages to identify macrophage activation mechanisms. Liposomes laden with STAT1 or STAT6 inhibitors, vehicle (control), or clodronate (depletion control) were delivered selectively to synovial macrophages via serial intra-articular injections up to 12 weeks after OA induction. Treatment effects on knee and hindpaw mechanical pain sensitivity were measured during OA development, along with synovitis, cartilage damage, and synovial macrophage infiltration using histopathology and immunofluorescence. Lastly, crosstalk between drug-treated synovial tissue and articular chondrocytes was assessed in co-culture. RESULTS: The majority of pathways identified by transcriptomic analyses in OA synovial macrophages involve STAT signaling. As expected, macrophage depletion reduced pain, but increased synovial tissue fibrosis and vascularization. In contrast, STAT6 inhibition in macrophages led to marked, sustained improvements in mechanical pain sensitivity and synovial inflammation without worsening synovial or cartilage pathology. During co-culture, STAT6 inhibitor-treated synovial tissue had minimal effects on healthy chondrocyte gene expression, whereas STAT1 inhibitor-treated synovium induced changes in numerous cartilage turnover-related genes. CONCLUSION: These results suggest that STAT signaling is a major mediator of synovial macrophage activation in experimental knee OA. STAT6 may be a key mechanism mediating the release of nociceptive factors from macrophages and the development of mechanical pain sensitivity. Whereas therapeutic depletion of macrophages paradoxically increases inflammation and fibrosis, blocking STAT6-mediated synovial macrophage activation may be a novel strategy for OA-pain management without accelerating tissue damage.


Assuntos
Osteoartrite do Joelho , Fator de Transcrição STAT6 , Animais , Ratos , Fibrose , Inflamação/patologia , Ativação de Macrófagos , Osteoartrite do Joelho/patologia , Dor/patologia , Membrana Sinovial/patologia , Fator de Transcrição STAT6/metabolismo
10.
Metabolism ; 155: 155834, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38479569

RESUMO

BACKGROUND: Circadian disruption is widespread and increases the risk of obesity. Timing of therapeutic interventions may promote coherent and efficient gating of metabolic processes and restore energy homeostasis. AIM: To characterize the diurnal postexercise metabolic state in mice and to identify the influence of diet-induced obesity on identified outcomes. METHODS: C57BL6/NTac male mice (6 wks of age) were fed a standard chow or high-fat diet for 5 weeks. At week 5, mice were subjected to a 60-min (16 m/min, 5 % incline) running bout (or sham) during the early rest (day) or early active (night) phase. Tissue and serum samples were collected immediately post-exercise (n = 6/group). In vivo glucose oxidation was measured after oral administration of 13C-glucose via 13CO2 exhalation analysis in metabolic cages. Basal and isoproterenol-stimulated adipose tissue lipolysis was assessed ex vivo for 1 h following exercise. RESULTS: Lean mice displayed exercise-timing-specific plasticity in metabolic outcomes, including phase-specificity in systemic glucose metabolism and adipose-tissue-autonomous lipolytic activity depending on time of day. Conversely, obesity impaired temporal postexercise differences in whole-body glucose oxidation, as well as the phase- and exercise-mediated induction of lipolysis in isolated adipose tissue. This obesity-induced alteration in diurnal metabolism, as well as the indistinct response to exercise, was observed concomitant with disruption of core clock gene expression in peripheral tissues. CONCLUSIONS: Overall, high-fat fed obese mice exhibit metabolic inflexibility, which is also evident in the diurnal exercise response. Our study provides physiological insight into exercise timing-dependent aspects in the dynamic regulation of metabolism and the influence of obesity on this biology.


Assuntos
Ritmo Circadiano , Dieta Hiperlipídica , Camundongos Endogâmicos C57BL , Obesidade , Condicionamento Físico Animal , Animais , Masculino , Obesidade/metabolismo , Camundongos , Ritmo Circadiano/fisiologia , Condicionamento Físico Animal/fisiologia , Dieta Hiperlipídica/efeitos adversos , Glucose/metabolismo , Lipólise , Tecido Adiposo/metabolismo , Metabolismo Energético/fisiologia
11.
JAMA Oncol ; 10(5): 621-633, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38512301

RESUMO

Importance: To date, no meta-analyses have comprehensively assessed the association of neoadjuvant chemoimmunotherapy with clinical outcomes in non-small cell lung cancer (NSCLC) in randomized and nonrandomized settings. In addition, there exists controversy concerning the efficacy of neoadjuvant chemoimmunotherapy for patients with NSCLC with programmed cell death 1 ligand 1 (PD-L1) levels less than 1%. Objective: To compare neoadjuvant chemoimmunotherapy with chemotherapy by adverse events and surgical, pathological, and efficacy outcomes using recently published randomized clinical trials and nonrandomized trials. Data Sources: MEDLINE and Embase were systematically searched from January 1, 2013, to October 25, 2023, for all clinical trials of neoadjuvant chemoimmunotherapy and chemotherapy that included at least 10 patients. Study Selection: Observational studies and trials reporting the use of neoadjuvant radiotherapy, including chemoradiotherapy, molecular targeted therapy, or immunotherapy monotherapy, were excluded. Main Outcomes and Measures: Surgical, pathological, and efficacy end points and adverse events were pooled using a random-effects meta-analysis. Results: Among 43 eligible trials comprising 5431 patients (4020 males [74.0%]; median age range, 55-70 years), there were 8 randomized clinical trials with 3387 patients. For randomized clinical trials, pooled overall survival (hazard ratio, 0.65; 95% CI, 0.54-0.79; I2 = 0%), event-free survival (hazard ratio, 0.59; 95% CI, 0.52-0.67; I2 = 14.9%), major pathological response (risk ratio, 3.42; 95% CI, 2.83-4.15; I2 = 31.2%), and complete pathological response (risk ratio, 5.52; 95% CI, 4.25-7.15; I2 = 27.4%) favored neoadjuvant chemoimmunotherapy over neoadjuvant chemotherapy. For patients with baseline tumor PD-L1 levels less than 1%, there was a significant benefit in event-free survival for neoadjuvant chemoimmunotherapy compared with chemotherapy (hazard ratio, 0.74; 95% CI, 0.62-0.89; I2 = 0%). Conclusion and Relevance: This study found that neoadjuvant chemoimmunotherapy was superior to neoadjuvant chemotherapy across surgical, pathological, and efficacy outcomes. These findings suggest that patients with resectable NSCLC with tumor PD-L1 levels less than 1% may have an event-free survival benefit with neoadjuvant chemoimmunotherapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Imunoterapia , Neoplasias Pulmonares , Terapia Neoadjuvante , Idoso , Humanos , Pessoa de Meia-Idade , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Imunoterapia/métodos , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/tratamento farmacológico , Terapia Neoadjuvante/efeitos adversos , Resultado do Tratamento
12.
Cancer Res ; 84(11): 1764-1780, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38471099

RESUMO

The tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC) plays a key role in tumor progression and response to therapy. The dense PDAC stroma causes hypovascularity, which leads to hypoxia. Here, we showed that hypoxia drives long-lasting epithelial-mesenchymal transition (EMT) in PDAC primarily through a positive-feedback histone methylation-MAPK signaling axis. Transformed cells preferentially underwent EMT in hypoxic tumor regions in multiple model systems. Hypoxia drove a cell autonomous EMT in PDAC cells, which, unlike EMT in response to growth factors, could last for weeks. Furthermore, hypoxia reduced histone demethylase KDM2A activity, suppressed PP2 family phosphatase expression, and activated MAPKs to post-translationally stabilize histone methyltransferase NSD2, leading to an H3K36me2-dependent EMT in which hypoxia-inducible factors played only a supporting role. Hypoxia-driven EMT could be antagonized in vivo by combinations of MAPK inhibitors. Collectively, these results suggest that hypoxia promotes durable EMT in PDAC by inducing a histone methylation-MAPK axis that can be effectively targeted with multidrug therapies, providing a potential strategy for overcoming chemoresistance. SIGNIFICANCE: Integrated regulation of histone methylation and MAPK signaling by the low-oxygen environment of pancreatic cancer drives long-lasting EMT that promotes chemoresistance and shortens patient survival and that can be pharmacologically inhibited. See related commentary by Wirth and Schneider, p. 1739.


Assuntos
Carcinoma Ductal Pancreático , Transição Epitelial-Mesenquimal , Histonas , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Camundongos , Histonas/metabolismo , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/tratamento farmacológico , Animais , Metilação , Sistema de Sinalização das MAP Quinases , Linhagem Celular Tumoral , Microambiente Tumoral , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto , Hipóxia Celular , Hipóxia Tumoral , Hipóxia/metabolismo , Proteínas F-Box , Histona Desmetilases com o Domínio Jumonji
13.
Arthroscopy ; 40(7): 2055-2057, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38428699

RESUMO

Although isolated posterior cruciate ligament (PCL) injuries often can be treated successfully without surgical intervention, in the setting of persistent instability or multiligamentous knee injury, PCL reconstruction is indicated. PCL reconstructions often have resulted in persistent postoperative laxity. Recent research suggests there may be a role for suture tape-augmented grafts, which have demonstrated decreased clinical and radiographic laxity as well as improved rates of return to previous level of activity, as compared with PCL reconstruction alone. Several biomechanical studies also have supported the use of suture tape augmentation in PCL reconstruction, and the use of suture tape augmentation or internal bracing and ligament surgery is gaining widespread popularity. These ultrahigh molecular weight polyethylene/polyester suture tapes have been shown to be safe and effective. We may be at the point at which the evidence supports the use of suture tape augmentation of PCL reconstruction.


Assuntos
Reconstrução do Ligamento Cruzado Posterior , Ligamento Cruzado Posterior , Humanos , Ligamento Cruzado Posterior/cirurgia , Ligamento Cruzado Posterior/lesões , Instabilidade Articular/cirurgia , Suturas , Traumatismos do Joelho/cirurgia , Técnicas de Sutura , Fita Cirúrgica
14.
J Proteome Res ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38421884

RESUMO

Proteoforms, the different forms of a protein with sequence variations including post-translational modifications (PTMs), execute vital functions in biological systems, such as cell signaling and epigenetic regulation. Advances in top-down mass spectrometry (MS) technology have permitted the direct characterization of intact proteoforms and their exact number of modification sites, allowing for the relative quantification of positional isomers (PI). Protein positional isomers refer to a set of proteoforms with identical total mass and set of modifications, but varying PTM site combinations. The relative abundance of PI can be estimated by matching proteoform-specific fragment ions to top-down tandem MS (MS2) data to localize and quantify modifications. However, the current approaches heavily rely on manual annotation. Here, we present IsoForma, an open-source R package for the relative quantification of PI within a single tool. Benchmarking IsoForma's performance against two existing workflows produced comparable results and improvements in speed. Overall, IsoForma provides a streamlined process for quantifying PI, reduces the analysis time, and offers an essential framework for developing customized proteoform analysis workflows. The software is open source and available at https://github.com/EMSL-Computing/isoforma-lib.

15.
Nature ; 627(8003): 367-373, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38383788

RESUMO

The posterior parietal cortex exhibits choice-selective activity during perceptual decision-making tasks1-10. However, it is not known how this selective activity arises from the underlying synaptic connectivity. Here we combined virtual-reality behaviour, two-photon calcium imaging, high-throughput electron microscopy and circuit modelling to analyse how synaptic connectivity between neurons in the posterior parietal cortex relates to their selective activity. We found that excitatory pyramidal neurons preferentially target inhibitory interneurons with the same selectivity. In turn, inhibitory interneurons preferentially target pyramidal neurons with opposite selectivity, forming an opponent inhibition motif. This motif was present even between neurons with activity peaks in different task epochs. We developed neural-circuit models of the computations performed by these motifs, and found that opponent inhibition between neural populations with opposite selectivity amplifies selective inputs, thereby improving the encoding of trial-type information. The models also predict that opponent inhibition between neurons with activity peaks in different task epochs contributes to creating choice-specific sequential activity. These results provide evidence for how synaptic connectivity in cortical circuits supports a learned decision-making task.


Assuntos
Tomada de Decisões , Vias Neurais , Lobo Parietal , Sinapses , Cálcio/análise , Cálcio/metabolismo , Tomada de Decisões/fisiologia , Interneurônios/metabolismo , Interneurônios/ultraestrutura , Aprendizagem/fisiologia , Microscopia Eletrônica , Inibição Neural , Vias Neurais/fisiologia , Vias Neurais/ultraestrutura , Lobo Parietal/citologia , Lobo Parietal/fisiologia , Lobo Parietal/ultraestrutura , Células Piramidais/metabolismo , Células Piramidais/ultraestrutura , Sinapses/metabolismo , Sinapses/ultraestrutura , Realidade Virtual , Modelos Neurológicos
16.
bioRxiv ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38405867

RESUMO

The General Stress Response promotes survival of bacteria in adverse conditions, but how sensor proteins transduce species-specific signals to initiate the response is not known. The serine/threonine phosphatase RsbU initiates the General Stress Response in B. subtilis upon binding a partner protein (RsbT) that is released from sequestration by environmental stresses. We report that RsbT activates RsbU by inducing otherwise flexible linkers of RsbU to form a short coiled-coil that dimerizes and activates the phosphatase domains. Importantly, we present evidence that related coiled-coil linkers and phosphatase dimers transduce signals from diverse sensor domains to control the General Stress Response and other signaling across bacterial phyla. These results additionally resolve the mystery of how shared sensory domains control serine/threonine phosphatases, diguanylate cyclases and histidine kinases, revealing a common coiled-coil linker transduction mechanism. We propose that this provides bacteria with a modularly exchangeable toolkit for the evolution of diverse signaling pathways.

17.
bioRxiv ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38405958

RESUMO

BACKGROUND: The Human Proteome Project has credibly detected nearly 93% of the roughly 20,000 proteins which are predicted by the human genome. However, the proteome is enigmatic, where alterations in amino acid sequences from polymorphisms and alternative splicing, errors in translation, and post-translational modifications result in a proteome depth estimated at several million unique proteoforms. Recently mass spectrometry has been demonstrated in several landmark efforts mapping the human proteoform landscape in bulk analyses. Herein, we developed an integrated workflow for characterizing proteoforms from human tissue in a spatially resolved manner by coupling laser capture microdissection, nanoliter-scale sample preparation, and mass spectrometry imaging. RESULTS: Using healthy human kidney sections as the case study, we focused our analyses on the major functional tissue units including glomeruli, tubules, and medullary rays. After laser capture microdissection, these isolated functional tissue units were processed with microPOTS (microdroplet processing in one-pot for trace samples) for sensitive top-down proteomics measurement. This provided a quantitative database of 616 proteoforms that was further leveraged as a library for mass spectrometry imaging with near-cellular spatial resolution over the entire section. Notably, several mitochondrial proteoforms were found to be differentially abundant between glomeruli and convoluted tubules, and further spatial contextualization was provided by mass spectrometry imaging confirming unique differences identified by microPOTS, and further expanding the field-of-view for unique distributions such as enhanced abundance of a truncated form (1-74) of ubiquitin within cortical regions. CONCLUSIONS: We developed an integrated workflow to directly identify proteoforms and reveal their spatial distributions. Where of the 20 differentially abundant proteoforms identified as discriminate between tubules and glomeruli by microPOTS, the vast majority of tubular proteoforms were of mitochondrial origin (8 of 10) where discriminate proteoforms in glomeruli were primarily hemoglobin subunits (9 of 10). These trends were also identified within ion images demonstrating spatially resolved characterization of proteoforms that has the potential to reshape discovery-based proteomics because the proteoforms are the ultimate effector of cellular functions. Applications of this technology have the potential to unravel etiology and pathophysiology of disease states, informing on biologically active proteoforms, which remodel the proteomic landscape in chronic and acute disorders.

18.
Cancer Res ; 84(8): 1333-1351, 2024 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-38277141

RESUMO

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are approved for breast cancer treatment and show activity against other malignancies, including KRAS-mutant non-small cell lung cancer (NSCLC). However, the clinical efficacy of CDK4/6 inhibitors is limited due to frequent drug resistance and their largely cytostatic effects. Through a genome-wide cDNA screen, we identified that bromodomain-containing protein 4 (BRD4) overexpression conferred resistance to the CDK4/6 inhibitor palbociclib in KRAS-mutant NSCLC cells. Inhibition of BRD4, either by RNA interference or small-molecule inhibitors, synergized with palbociclib to induce senescence in NSCLC cells and tumors, and the combination prolonged survival in a KRAS-mutant NSCLC mouse model. Mechanistically, BRD4-inhibition enhanced cell-cycle arrest and reactive oxygen species (ROS) accumulation, both of which are necessary for senescence induction; this in turn elevated GPX4, a peroxidase that suppresses ROS-triggered ferroptosis. Consequently, GPX4 inhibitor treatment selectively induced ferroptotic cell death in the senescent cancer cells, resulting in tumor regression. Cotargeting CDK4/6 and BRD4 also promoted senescence and ferroptosis vulnerability in pancreatic and breast cancer cells. Together, these findings reveal therapeutic vulnerabilities and effective combinations to enhance the clinical utility of CDK4/6 inhibitors. SIGNIFICANCE: The combination of cytostatic CDK4/6 and BRD4 inhibitors induces senescent cancer cells that are primed for activation of ferroptotic cell death by targeting GPX4, providing an effective strategy for treating cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Citostáticos , Ferroptose , Neoplasias Pulmonares , Animais , Camundongos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Quinase 4 Dependente de Ciclina , Proteínas Nucleares/metabolismo , Citostáticos/uso terapêutico , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Pulmonares/genética , Linhagem Celular Tumoral , Fatores de Transcrição/metabolismo , Quinase 6 Dependente de Ciclina , Inibidores de Proteínas Quinases/farmacologia
19.
Death Stud ; 48(2): 95-102, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36931063

RESUMO

End-of-life treatment preferences (EOLTPs) refer to the amount of medical intervention an individual would wish to receive in a life-threatening scenario. This study aimed to investigate relationships between older adults' EOLTPs and advance care planning (ACP). Using archival data from two interview surveys of community-dwelling older adults (study 1 n = 331, study 2 n = 338; age 60-102), results found that a desire for less end-of-life medical intervention was associated with greater EOL discussion with physicians. This relationship was explained by greater death preparation and younger age. Older adults may use ACP to limit unwanted medical interventions.


Assuntos
Planejamento Antecipado de Cuidados , Assistência Terminal , Humanos , Idoso , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Inquéritos e Questionários , Morte
20.
Nat Genet ; 56(1): 74-84, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38066188

RESUMO

Tissues are organized in cellular niches, the composition and interactions of which can be investigated using spatial omics technologies. However, systematic analyses of tissue composition are challenged by the scale and diversity of the data. Here we present CellCharter, an algorithmic framework to identify, characterize, and compare cellular niches in spatially resolved datasets. CellCharter outperformed existing approaches and effectively identified cellular niches across datasets generated using different technologies, and comprising hundreds of samples and millions of cells. In multiple human lung cancer cohorts, CellCharter uncovered a cellular niche composed of tumor-associated neutrophil and cancer cells expressing markers of hypoxia and cell migration. This cancer cell state was spatially segregated from more proliferative tumor cell clusters and was associated with tumor-associated neutrophil infiltration and poor prognosis in independent patient cohorts. Overall, CellCharter enables systematic analyses across data types and technologies to decode the link between spatial tissue architectures and cell plasticity.


Assuntos
Plasticidade Celular , Neoplasias , Humanos , Plasticidade Celular/genética , Neoplasias/genética
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