The rockefeller university

In the last two decades, metabolic and bariatric surgery (MBS) has become the mainstay of treatment for severe and complex obesity. The majority of patients undergoing MBS are women of childbearing age. Coupled with the dramatic increase in the utilization of MBS, caregivers are likely to encounter patients who have undergone MBS in routine practice. From this perspective, we highlight the different reproductive health challenges and issues encountered throughout the pre-operative, peri-operative, and postoperative phases.

Biomolecular condensates are key features of intracellular compartmentalization(1,2). As the most prominent nuclear condensate in eukaryotes, the nucleolus is a multiphase liquid-like structure in which ribosomal RNAs (rRNAs) are transcribed and processed, undergoing multiple maturation steps to form the small (SSU) and large (LSU) ribosomal subunits(3-5). However, how rRNA processing is coupled to the layered organization of the nucleolus is poorly understood owing to a lack of tools to precisely monitor and perturb nucleolar rRNA processing dynamics. Here we developed two complementary approaches to spatiotemporally map rRNA processing and engineer de novo nucleoli. Using sequencing in parallel with imaging, we found that rRNA processing steps are spatially segregated, with sequential maturation of rRNA required for its outward movement through nucleolar phases. By generating synthetic nucleoli in cells using an engineered rDNA plasmid system, we show that defects in SSU processing can alter the ordering of nucleolar phases, resulting in inside-out nucleoli and preventing rRNA outflux, while LSU precursors are necessary to build the outermost layer of the nucleolus. These findings demonstrate how rRNA is both a scaffold and substrate for the nucleolus, with rRNA acting as a programmable blueprint for the multiphase architecture that facilitates assembly of an essential molecular machine.

Heightened activity in the orbitofrontal cortex (OFC), a brain region that contributes to motivation, emotion, and reward-related decision-making, is a key clinical feature of major depressive disorder (MDD). However, the cellular and molecular substrates underlying this dysfunction remain unclear. Here, we performed cell-type-specific profiling of human OFC and unexpectedly mapped MDD-linked epigenomic features (including genetic risk variants) to non-neuronal cells, revealing significant glial dysregulation in this region. Characterization of MDD-specific chromatin loci further identified ZBTB7A-a transcriptional regulator of astrocyte reactivity-as an important mediator of MDD-related alterations. In rodent models, we found that Zbtb7a induction in astrocytes is both necessary and sufficient to drive stress-mediated behavioral deficits, cell-type-specific transcriptional/epigenomic signatures, and aberrant OFC astrocyte-neuronal communication in male mice-an established MDD risk factor. These findings thus highlight essential roles for astrocytes in OFC-mediated stress susceptibility and identify ZBTB7A as a critical and therapeutically relevant regulator of MDD-related OFC dysfunction.

Ferroptosis, a metabolic cell death process driven by iron-dependent phospholipid peroxidation, is implicated in various pathologies, including cancer. While metabolic factors such as glucose, lipids, and multiple amino acids have all been demonstrated to modulate ferroptosis, the role of oxygen, another fundamental metabolic component, in ferroptosis is not fully understood. Here, we show that cells acclimated to a low oxygen environment develop marked resistance to ferroptosis, and this resistance is independent of canonical oxygen-sensing pathway mediated by prolyl hydroxylases (PHDs) and HIF transcription factors. Instead, hypoxia suppresses ferroptosis by inhibiting KDM6A, a tumor suppressor and oxygen-dependent histone demethylase, leading to reduced expression of its transcriptional targets, including lipid metabolic enzymes ACSL4 and ETNK1, thus rewiring cellular phospholipid profile to a ferroptosis-resistant state. Relevant to cancer, pharmacological inhibition of the oncogenic histone methyltransferase EZH2, which opposes KDM6A activity, restored ferroptosis sensitivity of xenograft bladder tumor tissues harboring KDM6A mutation.

mRNA translation is rapidly upregulated after injury to supply proteins required for tissue regeneration. Augmented protein synthesis during regeneration has long been associated with increases in ribosome biogenesis and mTORC1 activity. Emerging evidence highlights the roles of multiple signaling pathways, RNA-binding proteins, and RNA modifications in tissue repair. Here, we review recent research on the molecular mechanisms underlying translational control in response to tissue damage. The findings underscore the importance of mRNA translation in regeneration and its potential therapeutic applications in tissue repair.

The Retroviridae are a family of viruses that reverse transcribe their RNA genome and integrate the resulting double-stranded DNA copy into the genome of the host cell. Retroviruses are well-documented pathogens that have been associated with a variety of diseases. The International Committee on Taxonomy of Viruses (ICTV) currently lists 65 species of retroviruses. As required by the ICTV, we have converted the species nomenclature to a binomial format comprised of the genus and a freeform epithet. Assigning binomial species names to classify new retroviruses will be facilitated when following the epithet rules described herein.

Bacterial sigma factors bind RNA polymerase (E) to form holoenzyme (E sigma), conferring promoter specificity to E and playing a key role in transcription bubble formation. sigma N is unique among sigma factors in its structure and functional mechanism, requiring activation by specialized AAA+ ATPases. E sigma N forms an inactive promoter complex where the N-terminal sigma N region I (sigma N-RI) threads through a small DNA bubble. On the opposite side of the DNA, the ATPase engages sigma N-RI within the pore of its hexameric ring. Here, we perform kinetics-guided structural analysis of de novo formed E sigma N initiation complexes and engineer a biochemical assay to measure ATPase-mediated sigma N-RI translocation during promoter melting. We show that the ATPase exerts mechanical action to translocate about 30 residues of sigma N-RI through the DNA bubble, disrupting inhibitory structures of sigma N to allow full transcription bubble formation. A local charge switch of sigma N-RI from positive to negative may help facilitate disengagement of the otherwise processive ATPase, allowing subsequent sigma N disentanglement from the DNA bubble.

Chronic inflammatory skin diseases arise from dysregulated interactions between tissue-resident and infiltrating cells, the complexity of which hinders disease understanding and treatment. To address this, here, we present a single-cell spatiotemporal atlas of murine type 2 skin inflammation using MERFISH and scRNA-seq. Analyzing similar to 430,000 cells during MC903-and oxazolone-induced dermatitis, we identify 39 cell types, including pro-inflammatory fibroblasts that resemble those in human atopic dermatitis. Spatial neighborhood analyses reveal basophils as potent activators of pro-inflammatory fibroblasts, with basophil-derived oncostatin-M (OSM) and IL-4 synergizing fibroblast-mediated feedforward basophil and immune recruitment. While fibroblast-specific deletion of the IL-4R alpha receptor disrupts inflammation in vivo, the addition of pharmacologic gp130 inhibition, a core component of the OSM receptor, results in synergistic reduction of inflammation. Our study establishes a basophil-fibroblast circuitry as a critical regulator of type 2 skin inflammation, redefining basophil biology and positioning fibroblasts as dynamic immune regulators and therapeutic targets in inflammatory skin disease.

Proper fuelling of the brain is critical to sustain cognitive function, but the role of fatty acid (FA) combustion in this process has been elusive. Here we show that acute block of a neuron-specific triglyceride lipase, DDHD2 (a genetic driver of complex hereditary spastic paraplegia), or of the mitochondrial lipid transporter CPT1 leads to rapid onset of torpor in adult male mice. These data indicate that in vivo neurons are probably constantly fluxing FAs derived from lipid droplets (LDs) through beta-oxidation to support neuronal bioenergetics. We show that in dissociated neurons, electrical silencing or blocking of DDHD2 leads to accumulation of neuronal LDs, including at nerve terminals, and that FAs derived from axonal LDs enter mitochondria in an activity-dependent fashion to drive local mitochondrial ATP production. These data demonstrate that nerve terminals can make use of LDs during electrical activity to provide metabolic support and probably have a critical role in supporting neuron function in vivo.

Isocitrate dehydrogenase 1/2 (IDH) mutations are early initiating events in acute myeloid leukemia (AML). The complex clonal architecture and cellular heterogeneity in IDH-mutant AML underlies the heterogeneous clinical presentation and outcomes. Integrating single-cell genotyping and transcriptomics, we demonstrate a stem-like and inflammatory phenotype of IDH-mutant AML and identify clone-specific programs associated with NPM1, NRAS, and SRSF2 co-mutations. Furthermore, these clones had distinct responses to treatment with combination IDH inhibitors and chemotherapy, including elimination, reconstitution of myeloid differentiation, or retention within progenitor populations. At relapse after IDH inhibitor monotherapy, we identify up-regulated stemness, inflammation, mitochondrial metabolism, and anti-apoptotic factors, as well as down-regulated major histocompatibility complex (MHC) class II antigen presentation. At the pre-leukemic stage, we observe upregulation of IDH2-associated pathways, including inflammation. We deliver a detailed phenotyping of IDH-mutant AML and a framework for dissecting contributions of recurrently mutated genes in AML at diagnosis and following therapy, with implications for precision medicine.