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Ultrasensitive proteomics uncovers nociceptor diversity and novel pain targets
Full text linkThe richness of our somatosensory experience is reflected in the functional diversity of somatic sensory neurons. Single-cell sequencing (scRNA) of sensory neurons has revealed a molecular basis for such diversity. However, sensory neuron diversity has yet to be captured at the level of the proteome. Here, we combined electrophysiology with deep visual proteomics (DVP) to quantify over 6,000 proteins from phenotypically-defined sensory neurons and identified novel proteomic markers of sensory neuron subtypes. Comparative analysis revealed both concordance and meaningful divergence between transcriptomes and proteomes. We further show that up to 3,000 proteins can be quantified from one-fourth of a single neuron, demonstrating subset-specific protein signatures. In culture, nociceptive neurons can be acutely sensitized to mechanical stimuli by nerve growth factor (NGF) which normally drives inflammatory pain in vivo. Indeed, overnight exposure of peptidergic nociceptors to NGF and a protein kinase C (PKC) activator produced functional sensitization associated with proteome changes. Functional knockdown experiments identified the up-regulated B3GNT2 enzyme as a potential effector of nociceptor sensitization. In summary, we present a high-resolution proteomic resource linking molecular identity to function, enabling the discovery of novel mechanisms underlying somatic sensation and pain sensitization
Lessons learned: quality analysis of optical coherence tomography in neuromyelitis optica
Full text linkINTRODUCTION: Optical coherence tomography (OCT)- derived retina measurements are markers for neuroaxonal visual pathway status. High- quality OCT scans are essential for reliable measurements, but their acquisition is particularly challenging in eyes with severe visual impairment, as often observed in neuromyelitis optica spectrum disorders (NMOSD). OBJECTIVE: To investigate OCT quality issues in real- world data from the international Collaborative Retrospective Study on Retinal OCT in Neuromyelitis Optica (CROCTINO). METHODS: We evaluated the quality of peripapillary and macular OCT scans, using Heidelberg Spectralis SD- OCT, Carl Zeiss Cirrus HD- OCT, or Topcon SD- OCT across 22 centers. Experienced graders applied OSCAR- IB criteria for OCT quality. Eyes were classified as severely visually impaired or not based on a 1.0 logMAR cut- off. Quality outcomes were compared using the Chi- square test. RESULTS: A total of 3075 OCT scans (1630 peripapillary, 1445 macular) from 539 people with NMOSD and related conditions were evaluated. Macular scans were rejected more often than peripapillary scans due to quality issues (20.1% vs. 14.5%, p < 0.001). Rejection rates were higher in eyes with severe visual impairment (peripapillary: 28.9%, macular: 41.6%) compared to eyes without severe visual impairment (peripapillary: 10.7%, p < 0.001; macular: 14.6%, p < 0.001). CONCLUSION: Our study revealed that approximately one in six scans was rejected due to low quality, with higher rejection rates in eyes with severe visual impairment. As scan quality can bias quantitative outcomes and artificial intelligence applications, these findings emphasize the unmet need for standardized OCT practices tailored to NMOSD and other conditions involving severe visual impairment
Oncogene inactivation-induced senescence facilitates tumor relapse
Full text linkOncogene-directed therapies can induce profound tumor regression in oncogene-addicted cancers such as BRAF-mutant melanoma and KRAS-driven pancreatic cancer, but their long-term benefit is often limited by resistance and early relapse. The mechanisms that allow residual cells to adapt, persist in a dormant state, and eventually fuel recurrence remain poorly understood. Here, we show that oncogene inactivation rapidly induces hallmark features of senescence together with a pro-inflammatory senescence-associated secretory phenotype (SASP). In vivo, oncogene inactivation-induced senescence (OIIS) predisposed tumors to relapse, characterized by polyploidy, chromosomal instability, and acquisition of alternative oncogenic pathways such as Mdm2 upregulation. Tumor microenvironment profiling by spectral flow cytometry revealed that relapse was associated with neovascularization and a shift from an immune-activated to an immunosuppressive milieu, indicating that senescent cells remodel their niche to promote regrowth. Importantly, OIIS features were also observed in human BRAFV600E melanoma cells treated with vemurafenib, confirming the clinical relevance of our findings. Together, our findings establish OIIS as a double-edged process: it initially restrains tumor growth but simultaneously creates conditions that favor recurrence. By defining the genetic, metabolic, cytogenetic, and microenvironmental hallmarks of OIIS, our study highlights adaptations to oncogene deprivation that limit the durability of targeted therapies
FOXO1 re-expression with a dual-recombinase allele rescues class switching in germinal center B cells
Full text linkModeling complex (patho)physiological processes by sequential targeted mutagenesis in mice is limited by the lack of precision of cellular targeting and complex breeding strategies. We present a new Cre/DreERT2 dual-recombinase germinal center B-cell (GCBC)-specific strain, with co-expression of the recombinases from a single allele. This enables highly efficient Cre-mediated FOXO1 knockout in GCBCs in vivo, followed by time controlled, efficient Dre-mediated FOXO1 re-expression in the same cells, leading to functional rescue of GC compartmentalization and class switch recombination. The present approach can be easily adapted to other cellular contexts
A protective cGAMP-mediated anti-tumor immune response can proceed without LRRC8/VRAC channels
No full textThe volume-regulated anion channel (VRAC) is a heterohexamer composed of LRRC8A and any of the four other LRRC8 paralogs (LRRC8B–E). Depending on their subunit composition, VRACs not only transport chloride, but also a range of organic substrates including 2′3′-cGAMP (cGAMP). Transfer of this immunomodulator from tumor to host cells is critical for antitumor immunity. Whether this process depends on VRAC in vivo remains incompletely understood. To address this issue, we studied subcutaneous MC38 and B16F10 tumors in syngeneic mice. Enhanced growth of MC38 tumors lacking cGAMP production confirmed the importance of tumor-produced cGAMP. The impact of VRAC-mediated cGAMP-efflux from tumor cells and its uptake into cells of the tumor microenvironment was investigated using LRRC8Adeficient tumor cells and recipient mice with selective LRRC8 subunit disruptions, respectively. Changed serum cytokines indicated moderate immunomodulatory effects of VRACmediated cGAMP export from MC38 tumors. However, tumor growth and the cGAMP-mediated antitumor immune response were independent of both tumor- and host-expressed VRAC. Disruption of any of the non-essential subunits, LRRC8B–LRRC8E, had no discernible effect on T or B cell development in mice. While tumor-produced cGAMP markedly suppresses tumor growth, transport of this immunomodulator to the tumor environment primarily involves transporters distinct from VRAC
Rice diet improves survival, blood pressure, and eye changes in 544 patients with malignant-hypertension
No full textBACKGROUND: The sodium-restricted rice diet (RD) was once the only effective treatment for malignant hypertension (MH); however, a modern, comprehensive data analysis is lacking. We determined patient survival and ocular improvements in 544 MH patients treated between 1942-1982. METHODS: At entry, systolic blood pressure (SBP) was ≥170 mmHg and retinal hemorrhage (n = 312), hemorrhage with papilledema (n= 211) or papilledema alone (n = 21) were present. Dates of death were available for 454 patients; ocular data (at baseline and again before day 365) for 342 patients with hemorrhage and 143 with papilledema. We used actuarial analysis to determine survival and resolution of ocular findings. We used Cox proportional hazards to calculate mortality hazard ratio (HR), and period life tables to estimate loss of longevity. RESULTS: Median initial SBP of 213.3 mmHg fell to 178.4 during year 1, and to ~143 after 9 years. RD patients survived longer than untreated patients: 1890 vs 540 days for patients with hemorrhage alone; 510 vs 180 days with both hemorrhage and papilledema. Few patients reached their expected longevity; median loss of potential life was 15.4 years. Compared to patients whose SBP fell <15 mmHg by 4 weeks, those with a fall ≥ 37 mmHg had HR for mortality of 0.32. Retinal hemorrhages cleared in 260/342 patients; papilledema, in 133/143. CONCLUSION: With RD treatment blood pressure decreased, and ocular abnormalities largely resolved. Survival improved, but predicted longevity was not achieved. The RD helped MH and could still provide a useful adjunct to pharmacologic therapy
DeBCR: a sparsity-efficient framework for image enhancement through a deep-learning-based solution to inverse problems
Full text linkComputational image enhancement for microscopy facilitates cutting-edge biological discovery. While promising, the commonly used deep learning methods are computationally expensive owing to the use of general-purpose architectures, which are inefficient for microscopy data. Here, we propose a sparsity-efficient neural network for image enhancement as a deep representation learning solution to inverse problems in imaging. To maximize accessibility, we developed a framework named DeBCR, consisting of a modular Python library and a user-friendly point-and-click DeBCR plugin for Napari, a popular bioimage analysis tool. We provide a detailed protocol for using the DeBCR as a library and a plugin, including data preparation, training, and inference. We compare the image restoration performance of DeBCR to ten current state-of-the-art models over four publicly available datasets spanning crucial modalities in advanced light microscopy. DeBCR demonstrates more robust performance in denoising and deconvolution tasks across all assessed microscopy modalities while requiring notably fewer parameters than existing models
Participation behaviour of different migrant groups in breast cancer screening - palpation of the breast and mammography. Results from the German national cohort (NAKO)
Full text linkBACKGROUND: For early detection of breast cancer, clinical palpation of the breast is offered yearly to all women aged 30 and older, and the German Mammography Screening Programme (MSP) offers biennial mammograms to all women aged 50 to 75 years. We investigated the utilization of both screening methods across various migrant groups in Germany, as well as the effect of German language proficiency. METHODS: Cross-sectional data on participation frequencies from the baseline examination (2014 to 2019) of more than 100,000 women of the German National Cohort study (NAKO) were analysed by migrant status. Adjusted logistic regression analyses were conducted for palpation and MSP to compare screening uptake among six migrant groups, and non-migrant population. RESULTS: Palpation of the breast was less frequently utilized in all migrant groups with odds ratios ranging from 0.5 (95% CI 0.4–0.6) for Turkish women to 0.9 for women from western countries (95% CI 0.7–1.1) compared to autochthone Germans. Lower German language proficiency further decreases its use. In contrast, odds ratios for MSP participation did not differ substantially compared to Germans ranging from 0.8 to 1.2. German language proficiency had little effect on MSP participation. DISCUSSION: In contrast to earlier studies, our findings suggest that MSP participation and motivation does not significantly differ by migration status or language skills. This may indicate that information on MSP is broadly accessible through established invitation procedures in Germany. However, lower uptake of breast palpation by a physician in some migrant populations highlights potential gaps in broader preventive care engagement
The regulatory interplay of the colorectal cancer biomarkers MACC1 and IER2 and its impact on metastatic cancer survival
Full text linkWe have previously identified MACC1 and IER2 as functional biomarkers in the context of colorectal cancer. In silico correlation analysis suggested a possible functional connection between the expressions of these biomarkers, given that a significant positive correlation between IER2 and MACC1 RNA was observed. In loss- and gain-of-function experiments, we found that MACC1 positively regulates the expression of IER2. Furthermore, pulldown experiments provided evidence for MACC1-IER2 protein–protein interactions. Functionally, MACC1 enhanced proliferation of HCT116 cells overexpressing IER2 but not of HCT116 cells with knockdown of IER2 expression. Patients with high expressions of both biomarkers lived significantly shorter, whereas those with low concentrations of both markers showed the longest survival. Taken together, these findings show a functional interplay between the colorectal biomarkers MACC1 and IER2, which, in turn, has an impact on the survival of colorectal cancer patients
Endogenous retroviral elements LTR8B and MER65 rewire PSG9 regulation to control trophoblast syncytialization and pre-eclampsia risk
Full text linkBACKGROUND: Understanding the causes of the exceptional rate of evolution of the mammalian placenta is likely to aid the understanding of placental development and the etiology of the human-specific pregnancy disorder pre-eclampsia (PE). As retroelements are often lineage-specific and known to be co-opted for placental function, here we consider the binding of the transcription factors GATA3 and DLX5 to retroelements. These factors are dysregulated in pre-eclampsia, as are their downstream consequences. RESULTS: We identify retrovirus-derived LTR8B as a placentally-relevant cis-regulatory element (CRE), not least within the PSG array, a primate-specific genomic region that exhibits high intraspecies variability. LTR8B at PSG9 is particularly influential affecting other PSG family members. Moreover, unique among PSGs, PSG9 produces both secreted and membrane-anchored isoforms. The retroelement MER65-int provides alternative polyA signals that enable the evolution of secreted PSG variants by truncating the ancestral CEACAM protein’s transmembrane domain. Functional characterization finds that LTR8B/PSG9 regulates the differentiation of multinucleated trophoblasts (syncytialization) and, like chorionic gonadotropin and syncytin1, determines the identity of syncytiotrophoblasts. Notably, PSG9 is the most upregulated PSG in PE, with levels correlated with GATA3 and DLX5 levels. CONCLUSIONS: Retroelements contribute to the structural and expression evolution of PSG genes, facilitating lineage-specific placental evolution. The LTR8B/PSG9 regulatory network plays a central role in syncytiotrophoblast differentiation. Given the association between DLX5/GATA3 dysregulation and elevated PSG9 levels, along with PSG9’s expression in the first trimester, PSG9 shows potential as a predictive biomarker for preeclampsia