The hair follicle stem cell niche is an immune-privileged microenvironment, characterized by reduced antigen presentation, thus shielding against permanent immune-mediated tissue damage. In this study, we demonstrated the protective role of hair follicle-specific epidermal growth factor receptor (EGFR) against scarring hair follicle destruction. Mechanistically, disruption of EGFR signaling generated a cell-intrinsic hypersensitivity within the JAK-STAT1 pathway, which, synergistically with interferon gamma expressing CD8 T-cell and NK-cell-mediated inflammation, compromised the stem cell niche. Hair follicle-specific genetic depletion of either JAK1/2 or STAT1 or therapeutic inhibition of JAK1/2 ameliorated the inflammation, restored skin barrier function and activated the residual stem cells to resume hair growth in mouse models of epidermal and hair follicle-specific EGFR deletion. Skin biopsies from EGFR inhibitor-treated and cicatricial alopecia patients revealed an active JAK-STAT1 signaling signature along with upregulation of antigen presentation and downregulation of key components of the EGFR pathway. Our findings offer molecular insights and highlight a mechanism-based therapeutic strategy for addressing chronic folliculitis associated with EGFR-inhibitor anti-cancer therapy and cicatricial alopecia.

Early detection is warranted to improve prognosis of gastric cancer (GC) but remains challenging. Liquid biopsy combined with machine learning will provide new insights into diagnostic strategies of GC. Lipid metabolism reprogramming plays a crucial role in the initiation and development of tumors. Here, we integrated the lipidomics data of three cohorts (n = 944) to develop the lipid metabolic landscape of GC. We further constructed the serum lipid metabolic signature (SLMS) by machine learning, which showed great performance in distinguishing GC patients from healthy donors. Notably, the SLMS also held high efficacy in the diagnosis of early-stage GC. Besides, by performing unsupervised consensus clustering analysis on the lipid metabolic matrix of patients with GC, we generated the gastric cancer prognostic subtypes (GCPSs) with significantly different overall survival. Furthermore, the lipid metabolic disturbance in GC tissues was demonstrated by multi-omics analysis, which showed partially consistent with that in GC serums. Collectively, this study revealed an innovative strategy of liquid biopsy for the diagnosis of GC on the basis of the serum lipid metabolic fingerprints.

The major genetic risk factor for Alzheimer's disease (AD), APOE4, accelerates beta-amyloid (Aβ) plaque formation, but whether this is caused by APOE expressed in microglia or astrocytes is debated. We express here the human APOE isoforms in astrocytes in an Apoe-deficient AD mouse model. This is not only sufficient to restore the amyloid plaque pathology but also induces the characteristic transcriptional pathological responses in Apoe-deficient microglia surrounding the plaques. We find that both APOE4 and the protective APOE2 from astrocytes increase fibrillar plaque deposition, but differentially affect soluble Aβ aggregates. Microglia and astrocytes show specific alterations in function of APOE genotype expressed in astrocytes. Our experiments indicate a central role of the astrocytes in APOE mediated amyloid plaque pathology and in the induction of associated microglia responses.

Bacterial cancer therapy (BCT) is a promising therapeutic for solid tumours. Salmonella enterica Typhimurium (STm) is well-studied amongst bacterial vectors due to advantages in genetic modification and metabolic adaptation. A longstanding paradox is the redundancy of T cells for treatment efficacy; instead, STm BCT depends on innate phagocytes for tumour control. Here, we used distal T cell receptor (TCR) and IFNγ reporter mice (Nr4a3-Tocky-Ifnγ-YFP) and a colorectal cancer (CRC) model to interrogate T cell activity during BCT with attenuated STm. We found that colonic tumour infiltrating lymphocytes (TILs) exhibited a variety of activation defects, including IFN-γ production decoupled from TCR signalling, decreased polyfunctionality and reduced central memory (T) formation. Modelling of T-cell-tumour interactions with a tumour organoid platform revealed an intact TCR signalosome, but paralysed metabolic reprogramming due to inhibition of the master metabolic controller, c-Myc. Restoration of c-Myc by deletion of the bacterial asparaginase ansB reinvigorated T cell activation, but at the cost of decreased metabolic control of the tumour by STm. This work shows for the first time that T cells are metabolically defective during BCT, but also that this same phenomenon is inexorably tied to intrinsic tumour suppression by the bacterial vector.

Melanin-like nanoparticles (MNPs) have recently emerged as valuable agents in antioxidant therapy due to their excellent biocompatibility and potent capacity to scavenge various reactive oxygen species (ROS). However, previous studies have mainly focused on acute ROS-related diseases, leaving a knowledge gap regarding their potential in chronic conditions. Furthermore, apart from their well-established antioxidant effects, it remains unclear whether MNPs target other intracellular molecular pathways. In this study, we synthesized ultra-small polyethylene glycol-incorporated Mn-chelated MNP (MMPP). We found that MMPP traversed the glomerular filtration barrier and specifically accumulated in renal tubules. Autosomal dominant polycystic kidney disease (ADPKD) is a chronic genetic disorder closely associated with increased oxidative stress and featured by the progressive enlargement of cysts originating from various segments of the renal tubules. Treatment with MMPP markedly attenuated oxidative stress levels, inhibited cyst growth, thereby improving renal function. Interestingly, we found that MMPP effectively inhibits a cyst-promoting gene program downstream of the cAMP-CREB pathway, a crucial signaling pathway implicated in ADPKD progression. Mechanistically, we observed that MMPP directly binds to the bZIP DNA-binding domain of CREB, leading to competitive inhibition of CREB's DNA binding ability and subsequent reduction in CREB target gene expression. In summary, our findings identify an intracellular target of MMPP and demonstrate its potential for treating ADPKD by simultaneously targeting oxidative stress and CREB transcriptional activity.

Pathogenic variants in either the mitochondrial or nuclear genomes are associated with a diverse group of human disorders characterized by impaired mitochondrial function. Within this group, an increasing number of families have been identified, where Mendelian genetic disorders implicate defective mitochondrial RNA biology. The PDE12 gene encodes the poly(A)-specific exoribonuclease, involved in the quality control of mitochondrial non-coding RNAs. Here, we report that disease-causing PDE12 variants in three unrelated families are associated with mitochondrial respiratory chain deficiencies and wide-ranging clinical presentations in utero and within the neonatal period, with muscle and brain involvement leading to marked cytochrome c oxidase (COX) deficiency in muscle and severe lactic acidosis. Whole exome sequencing of affected probands revealed novel, segregating bi-allelic missense PDE12 variants affecting conserved residues. Patient-derived primary fibroblasts demonstrate diminished steady-state levels of PDE12 protein, whilst mitochondrial poly(A)-tail RNA sequencing (MPAT-Seq) revealed an accumulation of spuriously polyadenylated mitochondrial RNA, consistent with perturbed function of PDE12 protein. Our data suggest that PDE12 regulates mitochondrial RNA processing and its loss results in neurological and muscular phenotypes.

Glycosaminoglycans are often deprioritized as targets for synthetic immunotherapy due to the complexity of glyco-epitopes and limited options for obtaining specific subtype binding. Solid tumors express proteoglycans that are modified with oncofetal chondroitin sulfate (CS), a modification normally restricted to the placenta. Here, we report the design and functionality of transient chimeric antigen receptor (CAR) T cells with selectivity to oncofetal CS. Following expression in T cells, the CAR could be "armed" with recombinant VAR2CSA lectins (rVAR2) to target tumor cells expressing oncofetal CS. While unarmed CAR T cells remained inactive in the presence of target cells, VAR2-armed CAR T cells displayed robust activation and the ability to eliminate diverse tumor cell types in vitro. Cytotoxicity of the CAR T cells was proportional to the concentration of rVAR2 available to the CAR, offering a potential molecular handle to finetune CAR T cell activity. In vivo, armed CAR T cells rapidly targeted bladder tumors and increased the survival of tumor-bearing mice. Thus, our work indicates that cancer-restricted glycosaminoglycans may be exploited as potential targets for CAR T cell therapy.

The microbes, nutrients and toxins that we are exposed to can have a profound effect on the composition and function of the gut microbiome. Thousands of peer-reviewed publications link microbiome composition and function to health from the moment of birth, right through to centenarians, generating a tantalizing glimpse of what might be possible if we could intervene rationally. Nevertheless, there remain relatively few real-world examples where successful microbiome engineering leads to beneficial health effects. Here we aim to provide a framework for the progress needed to turn gut microbiome engineering from a trial-and-error approach to a rational medical intervention. The workflow starts with truly understanding and accurately diagnosing the problems that we are trying to fix, before moving on to developing technologies that can achieve the desired changes.

The limited availability of therapeutic options for patients with triple-negative breast cancer (TNBC) contributes to the high rate of metastatic recurrence and poor prognosis. Ferroptosis is a type of cell death caused by iron-dependent lipid peroxidation and counteracted by the antioxidant activity of the selenoprotein GPX4. Here, we show that TNBC cells secrete an anti-ferroptotic factor in the extracellular environment when cultured at high cell densities but are primed to ferroptosis when forming colonies at low density. We found that secretion of the anti-ferroptotic factors, identified as monounsaturated fatty acid (MUFA) containing lipids, and the vulnerability to ferroptosis of single cells depends on the low expression of stearyl-CoA desaturase (SCD) that is proportional to cell density. Finally, we show that the inhibition of Sec-tRNAsec biosynthesis, an essential step for selenoprotein production, causes ferroptosis and impairs the lung seeding of circulating TNBC cells that are no longer protected by the MUFA-rich environment of the primary tumour.

Sepsis is a heterogeneous syndrome resulting from a dysregulated host response to infection. It is considered as a global major health priority. Sepsis is characterized by significant metabolic perturbations, leading to increased circulating metabolites such as lactate. In mammals, pyruvate is the primary substrate for lactate production. It plays a critical role in metabolism by linking glycolysis, where it is produced, with the mitochondrial oxidative phosphorylation pathway, where it is oxidized. Here, we provide an overview of all cytosolic and mitochondrial enzymes involved in pyruvate metabolism and how their activities are disrupted in sepsis. Based on the available data, we also discuss potential therapeutic strategies targeting these pyruvate-related enzymes leading to enhanced survival.

Hydrocephalus is a common neurological condition, characterized by the excessive accumulation of cerebrospinal fluid in the cerebral ventricles. Primary treatments for hydrocephalus mainly involve neurosurgical cerebrospinal fluid diversion, which hold high morbidity and failure rates, highlighting the necessity for the discovery of novel therapeutic approaches. Although the pathophysiology of hydrocephalus is highly multifactorial, impaired function of the brain ependymal cells plays a fundamental role in hydrocephalus. Here we show that GemC1 and McIdas, key regulators of multiciliated ependymal cell fate determination, induce direct cellular reprogramming towards ependyma. Our study reveals that ectopic expression of GemC1 and McIdas reprograms cortical astrocytes and programs mouse embryonic stem cells into ependyma. McIdas is sufficient to establish functional activity in the reprogrammed astrocytes. Furthermore, we show that McIdas' expression promotes ependymal cell regeneration in two different postnatal hydrocephalus mouse models: an intracranial hemorrhage and a genetic form of hydrocephalus and ameliorates the cytoarchitecture of the neurogenic niche. Our study provides evidence on the restoration of ependyma in animal models mimicking hydrocephalus that could be exploited towards future therapeutic interventions.

Environmental pollution is a major health problem that affects the health of individuals worldwide and is cumulative with other environmental stressors, contributing to the increasing prevalence of cancer, cardiometabolic, neurological and autoimmune diseases (Favé et al, 2018). Although being extensively studied, therapeutic strategies still rely primarily on exposure prevention, often with no option available to allow pollutant detoxification. In this issue of , Wang et al (Wang et al, 2024) investigated potential pharmacological strategies to allow the direct removal of phthalates, major environmental pollutants, from the liver.

Di-(2-ethylhexyl) phthalate (DEHP), an environmental pollutant, has been widely detected in both environmental and clinical samples, representing a serious threat to the homeostasis of the endocrine system. The accumulation of DEHP is notably pronounced in the liver and can lead to liver damage. The lack of effective high-throughput screening system retards the discovery of such drugs that can specifically target and eliminate the detrimental impact of DEHP. Here, by developing a Cy5-modified single-strand DNA-aptamer-based approach targeting DEHP, we have identified luteolin as a potential drug, which showcasing robust efficacy in detoxifying the DEHP by facilitating the expulsion of DEHP in both mouse primary hepatocytes and livers. Mechanistically, luteolin enhances the protein degradation of hepatic urocanate hydratase 1 (Uroc1) by targeting its Ala270 and Val272 sites. More importantly, trans-urocanic acid (trans-UCA), as the substrate of Uroc1, possesses properties similar to luteolin by regulating the lysosomal exocytosis through the inhibition of the ERK1/2 signal cascade. In summary, luteolin serves as a potent therapeutic agent in efficiently detoxifying DEHP in the liver by regulating the UCA/Uroc1 axis.

Cancer cell plasticity contributes significantly to the failure of chemo- and targeted therapies in triple-negative breast cancer (TNBC). Molecular mechanisms of therapy-induced tumor cell plasticity and associated resistance are largely unknown. Using a genome-wide CRISPR-Cas9 screen, we investigated escape mechanisms of NOTCH-driven TNBC treated with a gamma-secretase inhibitor (GSI) and identified SOX2 as a target of resistance to Notch inhibition. We describe a novel reciprocal inhibitory feedback mechanism between Notch signaling and SOX2. Specifically, Notch signaling inhibits SOX2 expression through its target genes of the HEY family, and SOX2 inhibits Notch signaling through direct interaction with RBPJ. This mechanism shapes divergent cell states with NOTCH positive TNBC being more epithelial-like, while SOX2 expression correlates with epithelial-mesenchymal transition, induces cancer stem cell features and GSI resistance. To counteract monotherapy-induced tumor relapse, we assessed GSI-paclitaxel and dasatinib-paclitaxel combination treatments in NOTCH inhibitor-sensitive and -resistant TNBC xenotransplants, respectively. These distinct preventive combinations and second-line treatment option dependent on NOTCH1 and SOX2 expression in TNBC are able to induce tumor growth control and reduce metastatic burden.

Fragmentomic features of circulating cell free mitochondrial DNA (ccf-mtDNA) including fragmentation profile, 5' end base preference and motif diversity are poorly understood. Here, we generated ccf-mtDNA sequencing data of 1607 plasma samples using capture-based next generation sequencing. We firstly found that fragmentomic features of ccf-mtDNA were remarkably different from those of circulating cell free nuclear DNA. Furthermore, region-specific fragmentomic features of ccf-mtDNA were observed, which was associated with protein binding, base composition and special structure of mitochondrial DNA. When comparing to non-cancer controls, six types of cancer patients exhibited aberrant fragmentomic features. Then, cancer detection models were built based on the fragmentomic features. Both internal and external validation cohorts demonstrated the excellent capacity of our model in distinguishing cancer patients from non-cancer control, with all area under curve higher than 0.9322. The overall accuracy of tissue-of-origin was 89.24% and 87.92% for six cancer types in two validation cohort, respectively. Altogether, our study comprehensively describes cancer-specific fragmentomic features of ccf-mtDNA and provides a proof-of-principle for the ccf-mtDNA fragmentomics-based multi-cancer detection and tissue-of-origin classification.

A hallmark feature of pancreatic ductal adenocarcinoma (PDAC) is massive intratumoral fibrosis, designated as desmoplasia. Desmoplasia is characterized by the expansion of cancer-associated fibroblasts (CAFs) and a massive increase in extracellular matrix (ECM). During fibrogenesis, distinct genes become reactivated specifically in fibroblasts, e.g., the disintegrin metalloprotease, ADAM12. Previous studies have shown that immunotherapeutic ablation of ADAM12 cells reduces fibrosis in various organs. In preclinical mouse models of PDAC, we observe ADAM12 expression in CAFs as well as in tumor cells but not in healthy mouse pancreas. Therefore, we tested prophylactic and therapeutic vaccination against ADAM12 in murine PDAC and observed delayed tumor growth along with a reduction in CAFs and tumor desmoplasia. This is furthermore associated with vascular normalization and alleviated tumor hypoxia. The ADAM12 vaccine induces a redistribution of CD8 T cells within the tumor and cytotoxic responses against ADAM12 cells. In summary, vaccination against the endogenous fibroblast target ADAM12 effectively depletes CAFs, reduces desmoplasia and delays the growth of murine PDACs. These results provide proof-of-principle for the development of vaccination-based immunotherapies to treat tumor desmoplasia.