The rockefeller university

Cell cycle events are ordered by cyclin-dependent kinases (CDKs), which phosphorylate hundreds of substrates. Multiple phosphatases oppose these CDK substrates, yet their collective role in regulating phosphorylation timing in vivo remains unclear. Here, we show that four phosphatases (PP2A-B55, PP2A-B56, CDC14, and PP1) each target distinct subsets of CDK substrate sites in vivo in fission yeast, influencing when phosphorylation occurs during G2 and mitosis. On average, sites dephosphorylated by CDC14 and PP2A-B56 are phosphorylated earlier during G2, followed by sites dephosphorylated by PP1 and PP2A-B55. This suggests that these phosphatases set different phosphorylation thresholds at the G2/M transition. Consistent with this, depleting PP2A-B55 or CDC14 accelerates mitotic onset, likely by advancing phosphorylation of their respective CDK substrates, suggesting these phosphorylation thresholds are important for regulating mitotic onset. Our findings establish in vivo phosphatase substrate specificity as a key factor regulating the timing of CDK substrate phosphorylation throughout the cell cycle.

How are systems supporting high-level cognition organized in the human brain? We hypothesize that cognitive processes involved in understanding people and places are implemented by distinct neural systems with parallel anatomical organization. We test this hypothesis using precision neuroimaging of individual human brains on diverse tasks involving perception and cognition in the domains of familiar people, places, and objects. We find that thinking about people and places elicits responses in distinct areas of high-level association cortex within the default mode network, spanning the frontal, parietal, and temporal lobes. Person-and place-preferring brain regions are systematically spatially adjacent across cortical zones. These areas have strongly domain-specific response profiles across visual, semantic, and episodic tasks and are specifically functionally connected to other parts of association cortex with like domain preference. Social and spatial networks remain anatomically separated at the apex of a unimodal-to-transmodal gradient across cortex and include regions with anatomical connections to the hippocampal formation. These results demonstrate the existence of parallel, domain-specific networks reaching the cortical apex.

The spatiotemporal regulation of morphogenetic signals, along with local tissue mechanics, guides morphogenesis and determines the shape of the embryo. However, how these signals integrate into developmental circuits remains poorly understood. Here, we developed a light-inducible strategy to induce BMP4 signaling with precise spatial coordinates in human pluripotent stem cells. Light-controlled BMP4 induces SMAD1-5 phosphorylation, resulting in amnion differentiation, and relies on a tension-dependent induction of WNT and NODAL for mesoderm differentiation. In response to BMP4 signaling, the mechanosensitive transcription factor YAP1 accumulates in the nucleus, where it represses WNT3 mRNA, regulating the induction of the three germ layers. Based on these findings, we developed a mathematical model that integrates tissue mechanics into morphogen dynamics, quantitatively explaining tissue-scale responses to BMP4 signaling. Thus, light induction of the morphogen BMP4 in human stem cell models elucidated the interplay between tissue mechanics and signaling at the onset of gastrulation.

Background: Polymicrobial sepsis is an infectious disease characterized by excessive inflammation and coagulation that is linked to more severe disease pathology, organ failure, and fatality. The plasma contact system is a protein cascade in the blood that can be activated by bacteria and contributes to both inflammation and coagulation. Objectives: To determine if inhibiting the plasma contact system by targeting highmolecular-weight kininogen (HK) can exert a protective effect on bacteria-induced coagulation. Methods: Polymicrobial cecal slurry (CS) was prepared from donor mice and used for ex vivo and in vivo experiments. CS was used in vivo to establish a murine model of polymicrobial sepsis. CS was incubated with mouse or human plasma ex vivo. Contact system activation was assessed by Western blot, and clotting was assessed spectroscopically. Our monoclonal antihuman HK antibody, 3E8, was used to determine how contact system inhibition could delay CS-induced coagulation ex vivo. Results: Polymicrobial CS activated the plasma contact system in vivo in mice and ex vivo in both mouse and human plasma. CS promoted coagulation in mouse and human plasma ex vivo. Treatment with our 3E8 anti-HK antibody protected against CS-induced contact system activation and coagulation. Conclusion: The plasma contact system was activated in the CS model of polymicrobial sepsis. Targeting HK in polymicrobial sepsis may have beneficial effects in limiting excessive coagulation and could represent a novel therapeutic avenue to promote survival in sepsis.

Myeloid cells-including monocytes, macrophages, dendritic cells, and granulocytes-are critical architects of the tumor microenvironment, in which they exert diverse functions ranging from immunosuppressive to immunostimulatory. Advances in single-cell omics and high-dimensional immune profiling have unveiled the remarkable heterogeneity and plasticity of these cells, revealing lineage-specialized functions that shape cancer immunity. These discoveries have sparked growing interest in therapeutically targeting myeloid cells as a next-generation strategy in cancer immunotherapy. As a complementary or alternative approach to T cell-centered immunotherapies, myeloid-directed therapies offer unique opportunities to reprogram the immune landscape, enhance antitumor responses, and overcome resistance mechanisms. In this review, we highlight recent discoveries in myeloid cell biology in cancer and discuss emerging therapeutic targets, with an emphasis on antibody-based therapies that have reached clinical development. We further provide perspective on translational challenges to implement these approaches into the clinic and discuss how Fc-engineering and rational antibody design can optimize myeloid cell engagement and amplify their immune effector functions. Together, these advances position myeloid-directed immunotherapies as a promising approach to enhance the efficacy and durability of cancer treatment.

The gut conveys nutritional, mechanical, and microbial signals to the brain to regulate physiology and behavior. Writing in Nature, Liu et al. reveal a colonic neuropod-vagus circuit that senses bacterial flagellin, highlighting microbial input as a rapid driver of feeding control and expanding paradigms of communication between the gut and the brain.

Mosquitoes, the world's deadliest animal, exemplify single-mating systems where females mate only once in their lifetime, making mate choice critically important for reproductive success and mosquito control. Despite this importance, the mechanisms behind mosquito mating and what prevents the female from mating again remain poorly understood. To address this gap, we developed a dual-color fluorescent sperm system in invasive Aedes aegypti mosquitoes and quantified mating patterns, confirming that 86%-96% of females mate only once. Using behavioral tracking of mating pairs, deep learning, and quantitative analysis at increasing resolution, we discovered that females actively control mating initiation through a previously undescribed behavior: genital tip elongation. This female response is triggered by rapidly evolving male genital structures, creating a lock-and-key mechanism that determines mating success. Comparative analysis revealed that Aedes albopictus, separated from Aedes aegypti by similar to 35 million years of evolution, employs a similar female-controlled system. Strikingly, we found that Aedes albopictus males bypass female control when attempting cross-species matings with Aedes aegypti females, but not with conspecific females. This "lock-picking" ability, combined with the known sterility induced by cross-species matings, could explain how Aedes albopictus competitively displaces Aedes aegypti populations in overlapping territories. Our findings redefine mosquito reproduction as a female-controlled process and establish a quantitative framework for investigating the molecular and neurobiological mechanisms underlying mating control and species competition in these globally important disease vectors.

BACKGROUND: The underlying mechanisms of atherosclerosis and strategies for identifying high cardiovascular risk in psoriasis are incompletely understood. Platelet activity is increased in psoriasis and induces vascular dysfunction. We investigated the platelet phenotype and platelet transcriptome as one potential mechanism to explain cardiovascular risk in psoriasis. METHODS: Psoriasis and controls underwent platelet aggregation and activation studies and platelet RNA sequencing to generate a psoriasis platelet transcriptomic score. The relationship between the platelet transcriptomic score and cardiovascular risk was assessed by arterial stiffness, coronary calcium, and longitudinally in an independent cohort of high cardiovascular-risk individuals undergoing lower extremity arterial revascularization. RESULTS: Psoriasis subjects (n=73; median age, 51 years; body surface area of psoriasis, 3%) compared with controls (n=56; median age, 41 years) trended older (P=0.08) and had greater body mass index (P=0.01) and higher hs-CRP (high-sensitivity C-reactive protein) values (P=0.01). Platelet aggregation in response to collagen (P=0.0049) and ADP (P=0.033), and leukocyte-, neutrophil-, and lymphocyte-platelet aggregates (P<0.05 for each comparison) were all higher in psoriasis versus controls. Platelet RNA sequencing comparing 51 patients with psoriasis with 39 controls identified 329 upregulated and 345 downregulated genes (P<0.05). Pathway analysis identified dysregulated platelet activation, apoptosis, VEGF (vascular endothelial growth factor), interferon, senescence, IL (interleukin)-1, and clotting cascade signaling between psoriasis and controls. Using a phenotypic rank-based scoring methodology, a psoriasis platelet transcriptomic score comprised of 142 genes differentiated psoriasis from controls. This score correlated with arterial stiffness (r=0.26; P=0.031) and coronary calcium (r=0.58; P=0.0069). In a separate cohort of high cardiovascular-risk patients undergoing lower extremity arterial revascularization, the psoriasis platelet transcriptomic score associated with incident myocardial infarction (adjusted hazard ratio, 3.7 [95% CI, 1.4-10.1]; P=0.015). CONCLUSIONS: Platelet aggregation and activation are increased in patients with controlled psoriatic disease, with the platelet transcriptome associated with proinflammatory, proatherothrombotic pathways, and cardiovascular risk. Our results warrant further investigation of platelet involvement promoting heightened cardiovascular disease in psoriasis.

Radioimmunotherapy using Ac-225, a highly cytotoxic alpha-particle emitter, has potential for treating advanced breast cancer, especially human epidermal growth factor receptor 2 (HER2)-positive cases. We use a pretargeted radioimmunotherapy (PRIT) approach consisting of a 3-step intravenous regimen (step 1: bispecific anti-HER2/anti-DOTA antibody; step 2: clearing agent; step 3: Ac-225-radiolabeled Proteus DOTA, or [Ac-225]Ac-Pr). Our goal was to establish curative Ac-225-PRIT with high therapeutic indices. Methods: The impact of [Ac-225]Ac-Pr specific activity was evaluated in the BT-474 breast xenograft model. We tested the effects of [Ac-225]Ac-Pr dosing during PRIT on tumor-targeting efficiency and tissue biodistribution. Using a Ac-225-PRIT regimen consisting of a ratio of 1.19 nmol of bispecific antibody to 0.60-0.66 nmol of [Ac-225]Ac-Pr, we evaluated therapy in the BT-474 model and a patient-derived xenograft model. BT-474-tumor-bearing mice were treated with 1 or 2 cycles of Ac-225-PRIT (37 kBq/cycle) separated by 1 wk. A dose escalation study was performed on the BT-474 model to establish an absorbed radiation dose of approximately 40 Gy (relative biological effectiveness [RBE], 5) as a nephrotoxic dose, as no such histologic findings were observed in prior studies at the 20.7-Gy (RBE, 5) renal dose level. Results: In the BT-474 model, 100% (20/20) achieved complete responses and histologic cure in 17 of 20 (85%) of the treated animals. One-cycle and 2-cycle treatments were equally effective. Treatments were well tolerated, with no chronic radiation toxicity documented during necropsy at 175 d. Dosimetry estimates (RBE, 5) per 37 kBq administered for tumors and kidneys were 210 and 3.5 Gy, respectively. In the patient-derived xenograft model, a single Ac-225-PRIT treatment led to 60% (3/5) complete response and prolonged survival (>93 d) versus no treatment (30 d; P = 0.0185). Lastly, a Ac-225-PRIT regimen was identified that induces severe chronic nephrotoxicity (41.4 Gy/592 kBq; RBE, 5). Conclusion: Safe and effective Ac-225-PRIT regimens were developed in 2 preclinical models of advanced HER2-positive human breast cancer with tumor cure without dose-limiting nephrotoxicity. This study establishes crucial preclinical dosimetry benchmarks for Ac-225-PRIT and provides a compelling rationale for its advancement into the clinic.

The synaptic vesicle glycoprotein 2A (SV2A), a member of the major facilitator superfamily (MFS), is a key target for antiseizure medications and a biomarker for synaptic density imaging. Despite its clinical importance, the mechanisms underlying SV2A ligand binding and modulation remain poorly understood. Here, we report sub-3 & Aring; resolution cryo-electron microscopy (cryo-EM) structures of human SV2A in its apo form and in complex with FDA-approved antiseizure medication levetiracetam; PET imaging tracer UCB-J; experimental antiseizure drug padsevonil; and allosteric modulator UCB1244283. We find that levetiracetam and UCB-J induce vestibule occlusion, a hallmark conformational transition of MFS transporters that had not been observed in previous SV2A structures. UCB1244283 binds to an allosteric site and enhances orthosteric ligand engagement by stabilizing the occluded state and slowing ligand dissociation. Notably, padsevonil occupies both orthosteric and allosteric sites, functionally precluding modulation. These findings uncover an allosteric mechanism of regulation and provide a structural framework for the development of modulators targeting SV2A and related MFS transporters.