Biology subjects

Beyaz, S.

Publications and source records attributed to Beyaz, S..

At least 19 recordsLinked to original sources

bioRxiv2026

A unique intestinal epithelial cell that expresses canonical lymphoid genes

Enterocytes and intestinal secretory cells harbor innate immunity. However, certain transcriptional programs -even beyond rearranged T- and B-cell receptor genes- are considered the exclusive purview of adaptive immune cells, including abundant and diverse intestinal intra-epithelial lymphocytes (IELs). Here, we identify and characterize columnar intestinal secretory cells that co-express classic epithelial and lymphoid genes, including Ptprc, Cd3e, Cd8a, and Gzma/b but not T- or B-cell receptors. These previously unrecognized epithelium-derived lymphoid-like cells (EDLCs) differ from any known resident cell type, including IELs or tuft cells. Rare in healthy mouse and human intestines, their numbers increase upon IL-25 stimulation or IL-10 receptor deficiency in vivo and upon IL-13 stimulation in vitro. EDLC chromatin is uniquely accessible at thousands of cis-elements, including lymphoid and epithelial loci. These findings reveal a transcriptionally and epigenetically distinct intestinal epithelial derivative that expresses prominent lymphoid character.

cell biology↗

bioRxiv2026

Microbial induction of MHC-II expression in colon cancer cells overcomes immunotherapy resistance and limits metastasis

Colorectal cancer remains a major cause of cancer mortality, and most microsatellite stable tumors derive little benefit from immune checkpoint blockade. Here, we identify a microbiome-dependent mechanism that converts immune-refractory colorectal cancer into a more immunologically responsive state. Using orthotopic mouse models spanning distinct genetic and immunologic contexts, we show that a Helicobacter-containing microbiome suppresses primary tumor growth and limits metastasis. This protective state is associated with increased intratumoral lymphocyte infiltration and stronger effector programs. Mechanistically, microbial exposure induces MHC class II expression in colon cancer cells to promote anti-tumor immunity. Tumor-intrinsic loss of CIITA abrogates microbial protection, whereas enforced CIITA expression is sufficient to increase intratumoral T cell accumulation, restrict progression and metastasis, and sensitize microsatellite-stable tumors to PD-1 and CTLA-4 blockade. In human microsatellite-stable patient-derived organoids, increased cancer-cell MHC-II enhanced interactions with autologous immune cells and increased tumor cell apoptosis. Together, these findings define a microbiome-cancer cell antigen presentation axis that restrains metastasis and overcomes immunotherapy resistance in colorectal cancer.

immunology↗

bioRxiv2026

An integrated multimodal pan-organ atlas of the female reproductive system across the lifespan contextualises gynaecological pathologies

Single cell transcriptomics has transformed our knowledge of reproductive tissues, yet studies remain largely organ-specific and temporally limited, leaving an incomplete picture of how cell types are distributed across the reproductive system over a lifetime. Gynaecological conditions affect more than one in four females and frequently span multiple organs and life stages. To advance our understanding and treatment of these conditions, an integrated cellular reference is essential. Here we present the Human Female Reproductive System Cell Atlas v1: a single-cell transcriptomic resource integrating more than 2M cells across the ovary, fallopian tube, uterus, cervix and vagina over the lifespan and menstrual cycle, further integrated with spatial transcriptomics and chromatin accessibility profiling to define 210 cell types through community-based annotation. Cross-organ integration resolves shared and organ-specific cellular states, identifying uterine-specific perivascular populations lining uterine spiral arteries, hypoxia-sensing type 3 innate lymphoid cells (ILC3s) enriched in the uterus, and lipid-associated macrophages with distinct subsets in each reproductive organ, including a previously undescribed population shared between the uterus and fallopian tube. Cross-organ integration enables detection of ectopic epithelial populations in otherwise healthy donors, including endometrial-like cells within a paediatric ovary consistent with early endometriosis. Integration with genome-wide association studies (GWAS) reveals that risk variants for major gynecological conditions act in mesenchymal cell states defined by specific transcriptional programmes and spatial or temporal context - for instance, heavy menstrual bleeding risk is enriched in basal fibroblasts (SFRP5) of the regenerative endometrial compartment. An integrated chromatin accessibility atlas provides peak-to-gene maps across reproductive cell types, enabling nomination of disease effector genes and providing the first regulatory evidence linking a Polyendocrine Metabolic Ovarian Syndrome (PMOS) risk locus to INHBB in granulosa cells. Together, this resource establishes a cellular and molecular framework for reproductive biology and the pathogenesis of neglected gynaecological conditions.

Cell Biology↗

bioRxiv2026

Comprehensive Molecular Characterization of High-Grade Endometrial Cancer in an Ancestrally-Diverse Cohort

Endometrial cancer (EC) exhibits one of the most striking racial disparities in oncology with black women disproportionately affected by aggressive high-grade subtypes that have poorer outcomes. While social and environmental factors undoubtedly contribute, the molecular underpinnings of these disparities remain critically understudied. To bridge this knowledge gap, we performed matched tumor-normal whole-genome sequencing and tumor transcriptome sequencing on 71 predominantly high-grade EC patient samples from an ancestrally diverse cohort of women recruited at a large hospital system in the New York metropolitan area. Our analysis characterized the germline and somatic mutation landscape, identifying ancestry-associated molecular differences. Notably, focal amplification of the EVI1 transcription factor (encoded at the MECOM locus) was significantly more frequent in African ancestry patients and associated with poorer clinical outcomes in an external validation cohort. Additionally transcriptome analysis revealed decreased CD8+ T cell infiltration with increasing African ancestry, suggesting tumor immune microenvironment differences with potential therapeutic implications. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=163 SRC="FIGDIR/small/721962v1_ufig1.gif" ALT="Figure 1"> View larger version (63K): org.highwire.dtl.DTLVardef@12125b9org.highwire.dtl.DTLVardef@133c787org.highwire.dtl.DTLVardef@707af0org.highwire.dtl.DTLVardef@97615c_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIThis study represents the most ancestrally diverse whole-genome sequencing characterization of high-grade endometrial cancer, with 62% of patients of African ancestry. C_LIO_LIMECOM focal amplification preferentially targets the oncogenic short isoform (EVI1) and is more frequent in patients of African ancestry. C_LIO_LIAfrican ancestry is associated with reduced CD8+ T cell infiltration and differential activation of immune and metabolic pathways in copy-number high endometrial tumors. C_LI

cancer biology↗

bioRxiv2026

A Single-Cell Atlas of Uterine Carcinosarcoma from Diverse Ancestries

Uterine carcinosarcoma (UCS) is an aggressive endometrial cancer defined by coexisting malignant epithelial and mesenchymal components, rapid metastatic dissemination, and poor therapeutic response. However, its cellular ecosystem remains poorly resolved, particularly in patients of African ancestry who are underrepresented in genomic datasets despite a disproportionate disease burden. Here, we generated a single-cell atlas of 15 primary and metastatic UCS specimens from a diverse cohort of 13 patients enriched for African ancestry, integrated with whole-genome sequencing. Malignant cells exhibited epithelial-like, mesenchymal-like, transitional, and stem/progenitor-like states within individual tumors that mapped to patient-specific copy number-defined subclones and RNA-velocity trajectories, supporting metaplastic state transitions. Compared to normal endometrium, primary tumors were enriched for epithelial-mesenchymal-transition (EMT), mTORC1, and glycolytic programs, whereas matched metastases show enhanced TNF-NF{kappa}B-associated invasive programs. The tumor microenvironment contained immunosuppressive myeloid states and diverse cancer-associated fibroblast (CAF) subsets, including pericyte-like and matrix-remodeling subsets that act as predicted communication hubs through chemokine and immune-checkpoint circuits. We found a CAF-centered CCL2-CXCL1/2-IL10 module linked to CD8 T-cell dysfunction and a TIGIT-CD96-PVR checkpoint module. These data define the UCS cellular ecosystem in which malignant plasticity is coupled to stromal-immune cell remodeling in a patient cohort of enriched ancestries and nominate stromal-immune axes for further therapeutic investigation.

cancer biology↗

bioRxiv2026

A Patient-derived Organoid Platform for Uterine Carcinosarcoma that Emulates Disease Characteristics

Uterine carcinosarcoma (UCS) is a rare but extremely lethal endometrial cancer that metastasizes early and resists current treatment modalities. It is biphasic, built from malignant epithelial and mesenchymal cells. Genomic studies indicate that these tumors are clonal, and that the mesenchymal cells arise from the epithelial cells through cancer cell plasticity. This biology has been hard to study, because faithful patient-derived models are scarce. The gap is widened by inequity. Women of African ancestry carry the greatest burden of UCS, yet are underrepresented in existing models. To address this, we established patient-derived organoids (PDOs) from an ancestrally inclusive UCS cohort, alongside matched normal endometrial PDOs. The organoids reproduced the biphasic histology of the original tumors. Across four sequencing platforms, they retained the tumor mutation and copy-number landscape, remained stable across passages, and expanded for up to 28 months. At single-cell resolution, UCS PDOs captured both malignant compartments and traced continuous transcriptional trajectories along the epithelial-to-mesenchymal axis, capturing patient-specific cancer cell plasticity. The models also nominated candidate vulnerabilities in proof-of-concept therapeutic testing. UCS PDOs were enriched for CREB-family transcriptional programs, and CREB inhibition reduced their viability. Combined FGFR and YAP inhibition outperformed either agent alone. Together, this work delivers a histologically, genomically, and transcriptionally faithful, ancestrally inclusive, and lineage-resolved UCS organoid platform for studying cancer cell plasticity and its vulnerabilities in an aggressive and inequitably burdened cancer.

cancer biology↗

bioRxiv2026

Diverse high-fat diets drive multi-omic reprogramming that persists after dietary reversal

Dietary fat composition modulates host physiology and the gut microbiome, but the long-term effects of specific fat sources and the extent to which these changes resolve after dietary reversal remain incompletely defined. Here, we present a longitudinal multi-omic resource of mice maintained for one year on a purified control diet, seven high-fat diets differing in predominant fat source, or reversal regimens in which animals were switched from high-fat to control diet after 4 or 9 months. We further incorporated two cohorts with distinct pre-existing microbiome configurations to determine how baseline community structure shapes diet-induced remodeling of the gut microbiome ecosystem. By integrating longitudinal phenotyping, fecal metagenomics, fecal metabolomics, plasma metabolomics and lipidomics, and intestinal single-cell RNA sequencing, we defined the shared and dietary fat-specific responses across host and microbiome compartments. Baseline microbiome composition strongly influenced microbial responses to diet, indicating that pre-existing community structure is a major determinant of dietary ecosystem remodeling. Although many altered features shifted toward baseline after dietary reversal, only approximately half of diet-associated microbial changes recovered within the study window. A subset of taxa exhibited persistent alterations, including sustained depletion of Lactobacillus johnsonii and Bifidobacterium pseudolongum and sustained enrichment of Alistipes finegoldii, consistent with a "microbiome memory" of prior high-fat diet exposure. This memory effect is mirrored in the host, by sustained suppression of major histocompatibility complex class II (MHC-II) gene expression in intestinal epithelial cells after dietary reversal. These findings indicate that dietary fats leave a lasting imprint on the host-microbiome interactome that survives dietary intervention. Together, these data establish a resource for defining how dietary fat source, baseline microbiome composition, and dietary history shape host-microbiome states. The entire resource is available online as an RShiny app.

systems biology↗

bioRxiv2025

CD8 T cells mediate immunosurveillance for neoantigen+ epithelial stem cells in the colon

Epithelial cells in the colon accumulate substantial numbers of somatic mutations, some of which can be recognised as neoantigens. The ability of CD8 T cells to survey for neoantigen+ cells in the healthy colon would provide an early detection mechanism to prevent cancer, but it is unclear whether neoantigen-specific CD8 T cells can mediate this process of immunosurveillance without becoming tolerant. To address this question, we used a genetically engineered mouse model to express a neoantigen in the epithelial cells of the adult proximal colon. Induction of neoantigen expression led to rapid elimination of neoantigen+ epithelial cells from the colon in a CD8 T cell-dependent manner. Neoantigen-specific CD8 T cells acquired cytolytic function within the colon tissue under steady-state conditions, which was required for elimination of the neoantigen+ epithelial cells. Despite the elimination of [~]25% of their epithelial cells over a two-day period, the colons looked histologically normal. Immunofluorescence and single-cell transcriptomic analyses revealed that neoantigen-specific CD8+ T cells specifically target neoantigen+ stem cells at the crypt base, which was associated with Ki67 in the crypt wall and abundance of neoantigen-negative stem cells. Infiltrating neoantigen-specific CD8 T cells made IFNg and expressed PD-1, raising the question of why PD-1-dependent suppression did not prevent the acquisition of effector functions by these neoantigen-specific CD8 T cells. Despite an increased signature of interferon-stimulated genes in colonic epithelial cells, PD-L1 expression was surprisingly absent. Moreover, we found that colonic epithelial stem cells also did not express PD-L1 under conditions of chronic inflammation, such as ulcerative colitis, immune checkpoint-induced colitis, and ageing, or when directly stimulated with IFN-{gamma} in vitro. Analyses of the PD-L1 gene promoter across humans and mice showed hypermethylation at sites associated with PD-L1 repression in cancer. Thus, our data support a model in which the acquisition of neoantigens by colonic epithelial cells triggers CD8 T cell-mediated immunosurveillance. This results in the elimination of PD-L1-negative neoantigen+ stem cells by effector CD8 T cells and simultaneous repair of the colon by neoantigen-negative epithelial cells to prevent immunopathology.

immunology↗

bioRxiv2025

Tumor Genotype Dictates Mitochondrial and Immune Vulnerabilities in Liver Cancer

Although oncogenic alterations influence tumor metabolism, how they impose distinct metabolic programs within a shared tissue context remains poorly defined. Here, we developed a rapid mitochondrial profiling platform to compare metabolites and proteins in genetic models of primary liver cancer (PLC). Analyses of six genetically distinct PLCs revealed that mitochondrial energy metabolism is largely dictated by oncogene identity. Kras-driven tumors required creatine metabolism to buffer energy demands during early tumorigenesis, whereas c-MYC-driven tumors relied on oxidative phosphorylation. Among c-MYC-driven PLCs, Pten-deficient tumors accumulated mitochondrial phosphoethanolamine, a precursor for phosphatidylethanolamine (PE) synthesis. Inhibition of PE synthesis selectively impaired the growth of Pten-deficient tumors and extended survival, in part through enhanced infiltration of CD8 T cells and sensitization to TNF-mediated cytotoxicity. Mechanistically, loss of PE elevated surface TNF receptor 2 (TNFR2), promoting TNF signaling and pro-inflammatory response. These findings uncover genotype-specific mitochondrial metabolic liabilities and establish PE synthesis as a tumor-intrinsic mechanism of immune evasion in PLC.

cancer biology↗

bioRxiv2025

Targeting Neutrophil Extracellular Traps to inhibit Colon Cancer Tumor Necrosis and Metastasis

Necrosis, conventionally thought of as a passive consequence of aggressive tumor growth, is associated with poor prognosis in colorectal cancer (CRC). We recently discovered that necrosis can be caused by neutrophils and neutrophil extracellular traps (NETs) aggregates driving vascular occlusion within the tumor vasculature in models of breast cancer. Here, we evaluated the role of NETs in inducing necrosis and metastasis in CRC. We found that the numbers of neutrophils primed to form NETs were elevated in the circulation of patients with CRC as compared to controls. CD177Low neutrophils were also elevated, and they showed reduced extravasation capacity with intact ability to form NETs. The extent of necrosis correlated with metastasis (stage IV disease), independent of tumor size, in our human cohort. In both human and murine CRC tumors, necrotic regions were characterized by neutrophil infiltration and NET accumulation, and NET aggregates were observed in the vasculature next to the necrotic regions. Single cell RNA sequencing and spatial transcriptomic analysis of human CRC and liver metastases revealed that necrotic tumors activate pathways associated with increased metastatic potential, including epithelial-to-mesenchymal-transition. Using a mouse model of DNA mismatch repair proficient CRC, we found neutrophil infiltration and NETs increased with tumor progression. Genetic or pharmacological inhibition of NET formation decreased necrosis and metastasis, and importantly enhanced chemotherapy efficacy. Altogether, our findings show that NET formation in human CRC is a key feature of tumor necrosis, that it is associated with metastasis, and further suggest that preventing NET formation may offer clinical benefits to CRC patients.

cancer biology↗

bioRxiv2025

Niche-driven phenotypic plasticity and cis-regulatory dynamics of a revised model for intestinal secretory differentiation

HIGHLIGHTSO_LIDelineation of chromatin and mRNA dynamics of intestinal secretory differentiation C_LIO_LIPaneth cells have few unique enhancers and share mRNAs and TFs with goblet cells C_LIO_LIUnlike other secretory derivatives, goblet and Paneth cells are not specified per se C_LIO_LINiche factors, especially BMP signaling, define goblet and Paneth phenotypes C_LI Enterocytes and four secretory cell types derive from stem cells located in intestinal crypts. Whereas secretory goblet and Paneth cells have long been considered distinct, we find high overlap in their transcripts and sites of accessible chromatin, in marked contrast to those of sibling enteroendocrine or tuft cells. Mouse and human goblet and Paneth cells express extraordinary fractions of selective antimicrobial genes, reflecting specific and variable gene responses to local niche signals. Wnt signaling retains few ATOH1+ secretory daughters in crypt bottoms, where an absence of BMP signaling potently induces Paneth features; those that move away from crypt bottoms acquire classic goblet properties. These post-mitotic cellular phenotypes and their underlying accessible cis-elements interconvert readily. Thus, goblet and Paneth properties represent alternative manifestations of a single versatile signal-responsive secretory cell. These findings reveal exquisite niche-dependent cell plasticity and the cis-regulatory dynamics of an updated unitarian model of the intestinal epithelial lineage.

cell biology↗

bioRxiv2024

Senolytic CAR T cells reverse aging-associated defects in intestinal regeneration and fitness

Intestinal stem cells (ISCs) drive the rapid regeneration of the gut epithelium to maintain organismal homeostasis. Aging, however, significantly reduces intestinal regenerative capacity. While cellular senescence is a key feature of the aging process, little is known about the in vivo effects of senescent cells on intestinal fitness. Here, we identify the accumulation of senescent cells in the aging gut and, by harnessing senolytic CAR T cells to eliminate them, we uncover their detrimental impact on epithelial integrity and overall intestinal homeostasis in natural aging, injury and colitis. Ablation of intestinal senescent cells with senolytic CAR T cells in vivo or in vitro is sufficient to promote the regenerative potential of aged ISCs. This intervention improves epithelial integrity and mucosal immune function. Overall, these results highlight the ability of senolytic CAR T cells to rejuvenate the intestinal niche and demonstrate the potential of targeted cell therapies to promote tissue regeneration in aging organisms.

cell biology↗

bioRxiv2022

Breast cancer progression and metastasis to lymph nodes reveals cancer cell plasticity and MHC class II-mediated immune regulation

Tumor-draining lymph nodes are critical sites for generating tumor antigen-specific T cells and are associated with durable immune responses. However, lymph nodes are often the first site of metastasis and lymph node metastases portend worse outcomes. Through cross-species single cell gene expression analysis of breast cancer progression and metastasis to lymph nodes, we uncovered features that define the heterogeneity, plasticity, and immune evasion of cancer cells. Notably, a subpopulation of metastatic cancer cells in the lymph node were marked by high levels of MHC class II (MHC-II) gene expression both in mice and humans. Mechanistically, the IFN-{gamma} and JAK/STAT signaling pathways mediate MHC-II expression in cancer cells. Ablation of IFNGR1/2 or CIITA, the transactivator of MHC-II, in cancer cells prevented tumor progression. Interestingly, MHC-II+ cancer cells lacked co-stimulatory molecule expression, engendered the expansion of regulatory T cells and blunted CD4+ effector T cells in the tumor-draining lymph nodes and favor tumor progression. Overall, our data suggests that cancer cell plasticity during breast cancer progression and metastasis to lymph nodes endows metastatic cells with the ability to avoid immune surveillance. These data provide the basis for new opportunities to therapeutically stimulate anti-cancer immune responses against local and systemic metastases.

cancer biology↗

bioRxiv2022

CRISPR-induced exon skipping of β-catenin reveals tumorigenic mutants driving distinct subtypes of liver cancer

CRISPR/Cas9-driven cancer modeling studies are based on disruption of tumor suppressor genes (TSGs) by small insertions or deletions (indels) that lead to frame-shift mutations. In addition, CRISPR/Cas9 is widely used to define the significance of cancer oncogenes and genetic dependencies in loss-of function studies. However, how CRISPR/Cas9 influences gain-of-function oncogenic mutations is elusive. Here, we demonstrate that single guide RNA targeting exon 3 of {beta}-catenin results in exon skipping and generates gain-of-function isoforms in vivo. CRISPR/Cas9-mediated exon skipping of {beta}-catenin induces liver tumor formation in synergy with YAPS127A in mice. We define two distinct exon skipping-induced tumor subtypes with different histological and transcriptional features. Notably, ectopic expression of two exon-skipped {beta}-catenin transcript isoforms together with YAPS127A phenocopies the two distinct subtypes of liver cancer. Moreover, we identify similar {beta}-catenin exon skipping events in hepatocellular carcinoma (HCC) patients. Collectively, our findings advance our understanding of {beta}-catenin-related tumorigenesis and reveal that CRISPR/Cas9 can be repurposed, in vivo, to study gain-of-function mutations of oncogenes in cancer.

cancer biology↗

bioRxiv2021

Parity-induced changes to mammary epithelial cells control NKT cell expansion and mammary oncogenesis

Pregnancy reprograms the epigenome of mammary epithelial cells (MECs) in a manner that control responses to pregnancy hormone re-exposure and the rate of carcinoma progression. However, the influence of pregnancy on the tissue microenvironment of the mammary gland is less clear. Here, we used single-cell RNA sequencing to comparatively profile the composition of epithelial and non-epithelial cells in mammary tissue from nulliparous and parous female mice. Our analysis revealed an expansion of {gamma}{delta} Natural Killer T (NKT) immune cells following pregnancy, in association with upregulation of immune signal molecules in post-pregnancy MECs. We show that expansion of NKT cells following pregnancy is due to elevated expression of the antigen presenting molecule CD1d protein, which is known to induce NKT activation. Accordingly, loss of CD1d expression on post-pregnancy MECs, or overall lack of activated NKT cells, accompanied the development of mammary oncogenesis in response to cMYC overexpression and loss of Brca1 function. Collectively, our findings illustrate how pregnancy-induced epigenetic changes modulate the communication between MECs and the mammary immune microenvironment, and establish a causal link between pregnancy, the immune microenvironment, and mammary oncogenesis.

developmental biology↗

bioRxiv2021

Excess dietary sugar impairs colonic epithelial regeneration in response to damage.

The colonic epithelium requires continuous renewal by intestinal stem cells (ISCs) to restore the barrier after damage and proliferation of epithelial cells is modulated by dietary metabolites. We demonstrate that mice fed a high sugar diet failed to repair colonic barrier damage, resulting in increased intestinal pathology. Culturing ISCs in excess sugar limited murine and human colonoid development, indicating that dietary sugar can directly affect colonic epithelial proliferation. Similarly, in vivo lineage tracing experiments and transcriptomic analysis indicated that dietary sugar impeded the proliferative potential of ISCs. ISCs and their immediate daughter cells predominantly rely on mitochondrial respiration for energy; however, metabolic analysis of colonic crypts revealed that a high sugar diet primed the epithelium for glycolysis without a commensurate increase in aerobic respiration. Colonoids cultured in high-glucose conditions accumulated glycolytic metabolites but not TCA cycle intermediates, indicating that the two metabolic pathways may not be coupled in proliferating intestinal epithelium. Accordingly, biochemically inducing pyruvate flux through the TCA cycle by inhibiting pyruvate dehydrogenase kinase rescued sugar-impaired colonoid development. Our results indicate that excess dietary sugar can directly inhibit epithelial proliferation in response to damage and may inform diets that better support the treatment of acute intestinal injury.

immunology↗

bioRxiv2021

Neurotensin neurons in the central extended amygdala control energy balance

Overeating and a sedentary life style are major causes of obesity and related metabolic disorders. Identification of the neurobiological processes that regulate energy balance will facilitate development of interventions for these disorders. Here we show that the Neurotensin-expressing neurons in the mouse IPAC (IPACNts), a nucleus of the central extended amygdala, bidirectionally coordinate hedonic feeding and physical activity, thereby regulating energy balance, metabolic processes and bodyweight. IPACNts are preferentially activated by consumption of highly palatable food or exposure to its taste and smell. Activating IPACNts promotes food intake in a palatability-dependent manner and decreases locomotion. Conversely, inhibiting IPACNts selectively reduces palatable food intake and dramatically enhances physical activity and energy expenditure, and in parallel stimulates physiological responses that oppose diet-induced obesity and metabolic dysfunctions. Thus, a single neuronal population, Neurotensin-expressing neurons in the IPAC, acts to control obesogenic and leptogenic processes by synergistically coordinating energy intake and expenditure with metabolism.

neuroscience↗

bioRxiv2020

Dietary suppression of MHC-II expression in intestinal stem cells enhances intestinal tumorigenesis

Little is known about how interactions between diet, immune recognition, and intestinal stem cells (ISCs) impact the early steps of intestinal tumorigenesis. Here, we show that a high fat diet (HFD) reduces the expression of the major histocompatibility complex II (MHC-II) genes in ISCs. This decline in ISC MHC-II expression in a HFD correlates with an altered intestinal microbiome composition and is recapitulated in antibiotic treated and germ-free mice on a control diet. Mechanistically, pattern recognition receptor and IFNg signaling regulate MHC-II expression in ISCs. Although MHC-II expression on ISCs is dispensable for stem cell function in organoid cultures in vitro, upon loss of the tumor suppressor gene Apc in a HFD, MHC-II- ISCs harbor greater in vivo tumor-initiating capacity than their MHC-II+ counterparts, thus implicating a role for epithelial MHC-II in suppressing tumorigenesis. Finally, ISC-specific genetic ablation of MHC-II in engineered Apc-mediated intestinal tumor models increases tumor burden in a cell autonomous manner. These findings highlight how a HFD alters the immune recognition properties of ISCs through the regulation of MHC-II expression in a manner that could contribute to intestinal tumorigenesis.

cancer biology↗