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Tate, M. C.

Publications and source records attributed to Tate, M. C..

7 recordsLinked to original sources

Temozolomide-associated inflammatory-repair remodeling in recurrent glioblastoma exposes a ROCK-linked therapeutic vulnerability

Background: Glioblastoma (GBM) adapts to therapy through coordinated malignant-cell and microenvironmental responses, but the mechanisms linking treatment-associated inflammation to tumor-cell phenotypic plasticity remain poorly defined. Here, we investigated whether preoperative temozolomide exposure is associated with inflammatory-repair remodeling and a ROCK-linked therapeutic vulnerability in recurrent GBM using a window-of-opportunity clinical trial cohort. Methods: We integrated patient-resolved single-cell transcriptomics, spatial RNA profiling and multiplex protein imaging with experimental perturbations and orthotopic glioblastoma models. In the presurgical window-of-opportunity subgroup of NCT05236036, four patients with recurrent glioblastoma received additional preoperative temozolomide (TMZ; 150 mg/m2/day for 5 days) before resection and were compared with three recurrent comparators who did not receive additional preoperative TMZ. Results: Across seven tumors, malignant-cell inflammatory activity covaried with integrin-binding and wound-healing programs (median partial {rho} = 0.45 and 0.42, respectively). Tumors exposed to preoperative TMZ showed enrichment of inflammatory, chemokine, adhesion and wound-healing programs (GSEA q < 0.05), with the direction of enrichment preserved in all leave-one-patient-out analyses. In two tumors exposed to preoperative TMZ, CXCL12 localized to vascular territories, whereas chemokine and wound-repair programs increased near injury-reference regions. Across seven specimens analyzed by multiplex protein imaging, MYL9 abundance correlated with local CXCL12 ({rho} = 0.61), phosphorylated MYPT1 ({rho} = 0.48) and nuclear phosphorylated STAT3 ({rho} = 0.45), with positive associations in every specimen. Experimentally, TMZ increased CXCL8 and reactive-state markers and enhanced subsequent scratch closure, while CXCL8 and CXCL12 increased MLC2 phosphorylation. Fasudil attenuated TNF-NF-{kappa}B, inflammatory-response and IFN-{gamma}-response programs in TMZ-treated cells and reduced scratch closure and p-MLC2 in complementary assays. Across three orthotopic models, fasudil plus TMZ prolonged survival versus TMZ alone (model-stratified HR, 0.21; 95% CI, 0.07-0.61; P = 0.001). Conclusions: These findings link treatment-associated inflammatory-repair programs with cytoskeletal remodeling and support further translational evaluation of fasudil plus TMZ in glioblastoma.

cancer biology↗

Myeloid-targeted RNA nanotherapeutics rewire cholesterol metabolism to unleash anti-tumor immunity in glioblastoma

Tumor-associated myeloid cells (TAMCs) dominate the glioblastoma (GBM) microenvironment and suppress anti-tumor immunity. Here, we identify cholesterol efflux via ABCA1 as a targetable metabolic checkpoint controlling TAMC immunosuppression in GBM. Reprogramming TAMC cholesterol metabolism using TAMC-targeting lipid nanoparticle encapsulating ABCA1 siRNA (ABCA1 LNP) converts TAMCs into potent antigen-presenting cells with enhanced pro-inflammatory activity and antigen-presenting capacity, thereby inducing T cell activation, expansion, and tumor infiltration. Mechanistically, ABCA1 blockade induces cholesterol accumulation in TAMC membranes, promoting lipid raft formation and enhancing MHC-I-mediated antigen presentation. In multiple preclinical GBM models, ABCA1 LNP treatment dramatically induces T cell priming, extends animal survival, and overcomes GBM resistance to radiotherapy and immune checkpoint therapy. This efficacy was well-maintained in stem-like and recurrent GBM models, GBM patient specimens, and a renal cell carcinoma model. Altogether, our work identifies cholesterol efflux as a targetable metabolic vulnerability in TAMCs to overcome therapy resistance in myeloid-rich, immunologically "cold" tumors.

immunology↗

Cortical Sites Critical for Speech and Language Exhibit Distinct fMRI-Derived Network Features

Direct electrocortical stimulation (ECS) is a well-established brain mapping technique that helps achieve safe and effective resection of epileptic foci, tumors or vascular malformations. Recent studies using electrocorticography (ECoG) suggest that ECS' exerted effects on brain sites are determined by the roles of those sites in larger networks. However, ECoG has limited spatial coverage. Here, we used functional magnetic resonance imaging from eighteen participants during performance of five language tasks to assess the functional network signatures of cortical sites defined as critical for speech and language by ECS. We found that critical sites causing speech arrests (SA) and language errors (LE) exhibited lower local and global connectivity than non-critical sites. LE sites showed greater connectivity across sub-networks (communities) than both non-critical and SA sites, indicating their role as connectors across functional networks. This connector profile of LE sites was most robust when considering network connectivity across the entire brain. Connector sites were concentrated primarily in temporal and inferior parietal cortices. Finally, these network features accurately predicted which sites were critical in machine learning models. These findings provide a preoperative framework for predicting cortical sites critical for speech and language function, which may ultimately help accelerate or improve brain mapping.

neuroscience↗

High-gamma activity is coupled to low-gamma oscillations in precentral cortices and modulates with movement and speech

Planning and executing motor behaviors requires coordinated neural activity among multiple cortical and subcortical regions of the brain. Phase-amplitude coupling between the high-gamma band amplitude and the phase of low frequency oscillations (theta, alpha, beta) has been proposed to reflect neural communication, as has synchronization of low-gamma oscillations. However, coupling between low-gamma and high-gamma bands has not been investigated. Here, we measured phase-amplitude coupling between low- and high-gamma in monkeys performing a reaching task and in humans either performing finger movements or speaking words aloud. We found significant coupling between low-gamma phase and high-gamma amplitude in multiple sensorimotor and premotor cortices of both species during all tasks. This coupling modulated with the onset of movement. These findings suggest that interactions between the low and high gamma bands are markers of network dynamics related to movement and speech generation.

neuroscience↗

Distinct representations of finger movement and force in human motor and premotor cortices

The ability to grasp and manipulate objects requires controlling both finger movement kinematics and isometric force. Previous work suggests that these behavioral modes are controlled separately, but it is unknown whether the cerebral cortex represents them differently. Here, we investigated this question by recording high-density electrocorticography from the motor and premotor cortices of seven human subjects performing a sequential movement-force motor task. We decoded finger movement (0.7{+/-}0.3 fractional variance account for; FVAF) and force (0.7{+/-}0.2 FVAF) with high accuracy, yet found different spatial representations. We also found clear distinctions in electrocorticographic activity by using deep learning methods to uncover state-space representations, and by developing a new metric, the neural vector angle. Thus, state-space techniques can help to investigate broad cortical networks. Finally, we were able to classify the behavioral mode from neural signals with high accuracy (90{+/-}6%). Thus, finger movement and force have distinct representations in motor/premotor cortices. This will inform our understanding of the neural control of movement as well as the design of grasp brain-machine interfaces.

neuroscience↗

Speech Synthesis from ECoG using Densely Connected 3D Convolutional Neural Networks

ObjectiveDirect synthesis of speech from neural signals could provide a fast and natural way of communication to people with neurological diseases. Invasively-measured brain activity (electrocorticography; ECoG) supplies the necessary temporal and spatial resolution to decode fast and complex processes such as speech production. A number of impressive advances in speech decoding using neural signals have been achieved in recent years, but the complex dynamics are still not fully understood. However, it is unlikely that simple linear models can capture the relation between neural activity and continuous spoken speech.\n\nApproachHere we show that deep neural networks can be used to map ECoG from speech production areas onto an intermediate representation of speech (logMel spectrogram). The proposed method uses a densely connected convolutional neural network topology which is well-suited to work with the small amount of data available from each participant.\n\nMain resultsIn a study with six participants, we achieved correlations up to r = 0.69 between the reconstructed and original logMel spectrograms. We transfered our prediction back into an audible waveform by applying a Wavenet vocoder. The vocoder was conditioned on logMel features that harnessed a much larger, pre-existing data corpus to provide the most natural acoustic output.\n\nSignificanceTo the best of our knowledge, this is the first time that high-quality speech has been reconstructed from neural recordings during speech production using deep neural networks.

neuroscience↗

Differential representation of articulatory gestures and phonemes in motor, premotor, and inferior frontal cortices

Speech is a critical form of human communication and is central to our daily lives. Yet, despite decades of study, an understanding of the fundamental neural control of speech production remains incomplete. Current theories model speech production as a hierarchy from sentences and phrases down to words, syllables, speech sounds (phonemes) and the movements of speech articulator muscles used to produce these sounds (articulatory gestures). Here, we investigate the cortical representation of articulatory gestures and phonemes in speech motor, premotor, and inferior frontal cortices. Our results indicate that primary motor and premotor areas represent gestures to a greater extent than phonemes, while inferior frontal cortex represents both gestures and phonemes. These findings suggest that the cortical control of speech production shares a common representation with that of other types of movement, such as arm and hand movements.

neuroscience↗