Distinct Subsets Research Articles

EPCO-02. HIGH CELLULAR PLASTICITY STATE OF HUMAN MEDULLOBLASTOMA LOCAL RECURRENCE AND DISTANT DISSEMINATION

Abstract Medulloblastoma (MB) is a heterogeneous pediatric brain tumor with variable clinical outcomes. Since current treatments facing limitations due to tumor resistance, less than 10% of relapsed patients survive beyond five years, with poorly understood recurrence mechanisms. To obtain cellular diversity and genetic characters in primary and recurrent MB, we conducted comprehensive analyses utilizing the single-cell/nucleus RNA sequencing (sc/snRNA-seq), snATAC-seq and spatial transcriptomics, complemented with bulk RNA sequencing and matched primary-recurrent whole exon profiles. SHH and Group_3 subgroups revealed distinct cellular subsets, including cycling, differentiated and quiescent tumor cells. Recurrent or disseminated MB displayed a dramatically different cellular ecosystem compared to primary tumors, with varying proportions of shared cell types. Local recurrence exhibited a higher enrichment of cycling tumor cells, while differentiated subset was notably present in disseminated lesions, indicating that local recurrences harbored the stronger proliferative capacity, whereas disseminations relatively well differentiated. Additionally, chromosomal alterations were assessed, reflecting distinct genetic subclones, such as chr7q gain and chr11 loss in Group_3 disseminations. Notably, the emergence of a subpopulation termed “high cellular plasticity (HCP)” during MB progression was noted, characterized by dynamic adaptability and stemness properties. As validated, HCP state was associated with increased chromatin accessibility, contributing to tumor recurrence and immune microenvironment remodeling. Functionally, inhibiting markers associated with HCP cells, such as PTPRZ1, efficiently suppressed MB metastasis in preclinical models. In conclusion, our findings fill the critical knowledge gaps in understanding the cellular diversity, chromosomal alterations and biological dynamics in MB recurrence and dissemination, offering potential therapeutic interventions.

Desmoplakin Cardiomyopathy in Pediatric Patients: A Distinct, Underrecognized Cohort of Arrhythmogenic Cardiomyopathy

BACKGROUND: DSP cardiomyopathy is a distinct subset of arrhythmogenic cardiomyopathy, reported primarily in adults, that has predominantly left ventricular involvement and features of myocarditis. Clinical characteristics, risk stratification, and management of pediatric patients with DSP variants are not well known. We sought to identify phenotypic features and prognosis of pediatric patients with DSP pathogenic or likely pathogenic variants. METHODS: Multicenter, retrospective study of patients <21 years of age with DSP variants from 6 tertiary pediatric hospitals. RESULTS: Thirty-four patients, including 10 probands with clinical disease and 24 genotype-positive phenotype-negative patients, were included in the study. The majority of probands were initially diagnosed with myocarditis (50%) and had biventricular (60%) or left ventricular predominant (40%) disease. Chest pain was the most common symptom at presentation (30%), and all had troponin elevation. Probands with homozygous or compound heterozygous DSP variants were likely to present at an early age (<13 years) with symptoms of heart failure, severe biventricular involvement, and dermatologic abnormalities. Low-voltage QRS was the most prominent ECG abnormality. Of those who underwent implantable cardioverter defibrillator implantation, 50% received appropriate implantable cardioverter defibrillator therapy and were found to have significant biventricular involvement in addition to severe left ventricular dysfunction with an ejection fraction <35%. CONCLUSIONS: DSP cardiomyopathy in children and adolescents has varied phenotypic manifestations based on age and genotype and often can be diagnosed as myocarditis. Severe left ventricular dysfunction and biventricular involvement may be associated with a higher likelihood of malignant ventricular tachyarrhythmia.

Characterization of metastasis-specific macrophages in colorectal cancer for prognosis prediction and immunometabolic remodeling

This study develops a prognostic model to predict metastasis and prognosis in colorectal cancer liver metastases by identifying distinct macrophage subsets. Using scRNA-seq data from primary colorectal cancer and liver metastases, we dissected the cellular landscape to find unique macrophage subpopulations, particularly EEF1G + macrophages, which were prevalent in liver metastases. The study leveraged data from GSE231559, TCGA, and GEO databases to construct an 8-gene risk model named EMGS, based on the EEF1G + macrophage gene signature. Patients were divided into high-risk and low-risk groups using the median EMGS score, with the high-risk group showing significantly worse survival. This group also demonstrated upregulated pathways associated with tumor progression, such as epithelial-mesenchymal transition and angiogenesis, and downregulated metabolic pathways. Moreover, the high-risk group presented an immunosuppressive microenvironment, with a higher TIDE score indicating lower effectiveness of immunotherapy. The study identifies potential drugs targeting the high-risk group, suggesting therapeutic avenues to improve survival. Conclusively, the EMGS score identifies colorectal cancer patients at high risk of liver metastases, highlighting the role of specific macrophage subsets in tumor progression and providing a basis for personalized treatment strategies.

Dynamic transcriptome analysis of osteal macrophages identifies distinct subset with senescence features in experimental osteoporosis.

Given the potential fundamental function of osteal macrophages in bone pathophysiology, we study here their precise function in experimental osteoporosis. Gene profiling of osteal macrophages from ovariectomized mice demonstrated the upregulation of genes that were involved in oxidative stress, cell senescence and apoptotic process. A scRNA-seq analysis revealed that osteal macrophages were heterogenously clustered into 6 subsets that expressed proliferative, inflammatory, anti-inflammatory and efferocytosis gene signatures. Importantly, postmenopausal mice exhibited a 20-fold increase in subset-3 that showed a typical gene signature of cell senescence and inflammation. These findings suggest that the decreased production of estrogen due to postmenopause altered the osteal macrophages subsets, resulting in a shift toward cell senescence and inflammatory conditions in the bone microenvironment. Furthermore, adoptive macrophage transfer onto calvarial bone was performed and mice that received oxidative-stressed macrophages exhibited greater osteolytic lesions than control macrophages, suggesting the role of these cells in development of inflammaging in bone microenvironment. Consistently, depletion of senescent cells and oxidative-stressed macrophages subset alleviated the excessive bone loss in postmenopausal mice. Our data provided a new insight into the pathogenesis of osteoporosis and sheds light on a new therapeutic approach for the treatment/prevention of postmenopausal osteoporosis.

The myocardium of human dilated nonischemic cardiomyopathy harbors unique tissue-resident lymphocyte subsets

Abstract Purpose The etiology of dilated nonischemic cardiomyopathy (NICM) is often unclear, but thought to be multifactorial, involving an interplay between genetic factors and direct myocardial damage caused by infection, autoimmunity, or toxins. Tissue-resident lymphocytes are non-circulating immune cells which are retained within various tissues and play integral roles in maintaining homeostasis, responding to infection, regulating inflammation, and mediating tissue repair. Despite their likely involvement in various cardiac pathologies, the presence of tissue-resident lymphocytes in the human heart has not yet been well-characterized, neither in health nor in disease. Methods Human left ventricular tissue and paired peripheral blood samples were obtained from six adult organ donors with normal heart function who died of noncardiac causes and from the explants of six adult patients with end-stage nonischemic cardiomyopathy. Heart tissue was processed using mechanical and enzymatic digestion. Mononuclear cells were isolated from both heart and paired blood by density centrifugation. Isolated mononuclear cells were surface stained with an antibody cocktail and interrogated using multidimensional flow cytometry. Results The adult human heart contains a diverse immune cell population (Fig 1A). Both healthy and NICM cardiac lymphocytes express distinct phenotypic profiles which resemble those of resident lymphocytes found across various tissues, distinct from those isolated from paired blood. Frequencies of effector memory T (Tem) cells (CD45RA- CCR7-) were higher in heart than in blood among both CD4+ and CD8+ T-cells. In heart compared to blood, significantly more Tem expressed CD69, a canonical marker of tissue-resident memory T (Trm) cells (Fig 1B). Cardiac Trm, especially CD8+ Trm, expressed classical Trm signature markers including integrins CD103 (epithelial binding) and CD49a (collagen binding). NICM Trm expressed more CD49a than healthy heart Trm (Fig 1C). NK-cells also demonstrated higher CD69 expression (trNK) in heart than in blood, with associated expression of CD103, CD49a, and CXCR6 (Fig 1D). Compared to healthy hearts, NICM trNK were predominantly CD56bright/CD16- (Fig 1E and 1F) and expressed less CD57 (Fig 1D), overall indicating a less mature state with lower cytotoxic potential. Confocal imaging of cardiac tissue revealed CD69-expressing tissue-resident lymphocytes within the cardiac interstitium. Conclusions The adult human heart contains diverse populations of lymphocytes which express canonical markers of tissue residency, similar to lymphocytes resident in other tissues. Compared to healthy hearts, NICM hearts have more CD49a+ Trm, perhaps related to greater fibrosis, and also harbor a distinct subset of immature tissue-resident NK cells which may shed light on pathophysiology. Future work is focused on better exploring the functional phenotypes of these resident cells and better localizing them within the myocardium.FA - Figure 1

Identifying distinct phenotypes of patients with juvenile systemic lupus erythematosus: results from a cluster analysis by the Egyptian college of rheumatology (ECR) study group

PurposeJuvenile systemic lupus erythematosus (J-SLE) is a complex, heterogeneous disease affecting multiple organs. However, the classification of its subgroups is still debated. Therefore, we investigated the aggregated clinical features in patients with J-SLE using cluster analysis. Methods: Patients (≤ 16 years) diagnosed using the Systemic Lupus International Collaborating Clinics (SLICC) classification criteria were identified from the clinical database of the Egyptian College of Rheumatology (ECR) SLE study group. Demographic data, clinical characteristics, laboratory features, and current therapies were selected. A cluster analysis was performed to identify different clinical phenotypes. Results: Overall, 404 patients, of whom 355 (87.9%) were female, had a mean age at diagnosis of 11.2 years and a mean disease duration of 2.3 years. We identified four distinct subsets of patients. Patients in cluster 1 (n = 103, 25.5%) were characterized predominantly by mucocutaneous and neurologic manifestations. Patients in cluster 2 (n = 101, 25%) were more likely to have arthritis and pulmonary manifestations. Cluster 3 (n = 71, 17.6%) had the lowest prevalence of arthritis and lupus nephritis (LN), indicative of mild disease intensity. Patients in cluster 4 (n = 129, 31.9%) have the highest frequency of arthritis, vasculitis, and LN. Cluster 1 and 4 patients had the highest disease activity index score and were less likely to use low-dose aspirin (LDA). The SLE damage index was comparable across clusters. Conclusions: Four identified J-SLE clusters express distinct clinical phenotypes. Attention should be paid to including LDA in the therapeutic regimen for J-SLE. Further work is needed to replicate and clarify the phenotype patterns in J-SLE.

Heme catabolism and heme oxygenase-1-expressing myeloid cells in pathophysiology

Although the pathological significance of myeloid cell heterogeneity is still poorly understood, new evidence indicates that distinct macrophage subsets are characterized by specific metabolic programs that influence disease onset and progression. Within this scenario, distinct subsets of macrophages, endowed with high rates of heme catabolism by the stress-responsive enzyme heme oxygenase-1 (HO-1), play critical roles in physiologic and pathological conditions. Of relevance, the substrates of HO-1 activity are the heme groups that derive from cellular catabolism and are converted into carbon monoxide (CO), biliverdin and Fe2+, which together elicit anti-apoptotic, anti-inflammatory activities and control oxidative damage. While high levels of expression of HO-1 enzyme by specialized macrophage populations (erythrophagocytes) guarantee the physiological disposal of senescent red blood cells (i.e. erythrocateresis), the action of HO-1 takes on pathological significance in various diseases, and abnormal CO metabolism has been observed in cancer, hematological diseases, hypertension, heart failure, inflammation, sepsis, neurodegeneration. Modulation of heme catabolism and CO production is therefore a feasible therapeutic opportunity in various diseases. In this review we discuss the role of HO-1 in different pathological contexts (i.e. cancer, infections, cardiovascular, immune-mediated and neurodegenerative diseases) and highlight new therapeutic perspectives on the modulation of the enzymatic activity of HO-1.

Age-associated imbalance in immune cell regeneration varies across individuals and arises from a distinct subset of stem cells.

The age-associated decline in immunity manifests as imbalanced adaptive and innate immune cells, which originate from the aging of the stem cells that sustain their regeneration. Aging variation across individuals is well recognized, but its mechanism remains unclear. Here, we used high-throughput single-cell technologies to compare mice of the same chronological age that exhibited early or delayed immune aging phenotypes. We found that some hematopoietic stem cells (HSCs) in earlyaging mice upregulated genes related to aging, myeloid differentiation, and stem cell proliferation. Delayed aging was instead associated with genes involved in stem cell regulation and the response to external signals. These molecular changes align with shifts in HSC function. We found that the lineage biases of 30% to 40% of the HSC clones shifted with age. Moreover, their lineage biases shifted in opposite directions in mice exhibiting an early or delayed aging phenotype. In earlyaging mice, the HSC lineage bias shifted toward the myeloid lineage, driving the aging phenotype. In delayedaging mice, HSC lineage bias shifted toward the lymphoid lineage, effectively counteracting aging progression. Furthermore, the anti-aging HSC clones did not increase lymphoid production but instead decreased myeloid production. Additionally, we systematically quantified the frequency of various changes in HSC differentiation and their roles in driving the immune aging phenotype. Taken together, our findings suggest that temporal variation in the aging of immune cell regeneration among individuals primarily arises from differences in the myelopoiesis of a distinct subset of HSCs. Therefore, interventions to delay aging may be possible by targeting a subset of stem cells.

Amyloid-β (Aβ) immunotherapy induced microhemorrhages are linked to vascular inflammation and cerebrovascular damage in a mouse model of Alzheimer’s disease

BackgroundAnti-amyloid-β (Aβ) immunotherapy trials have revealed amyloid-related imaging abnormalities (ARIA) as the most prevalent and serious adverse events linked to pathological changes in cerebral vasculature. Recent studies underscore the critical involvement of perivascular macrophages and the infiltration of peripheral immune cells in regulating cerebrovascular damage. Specifically, Aβ antibodies engaged at cerebral amyloid angiopathy (CAA) deposits trigger perivascular macrophage activation and the upregulation of genes associated with vascular permeability. Nevertheless, further research is needed to understand the immediate downstream consequences of macrophage activation, potentially exacerbating CAA-related vascular permeability and microhemorrhages linked to Aβ immunotherapy.MethodsThis study investigates immune responses induced by amyloid-targeting antibodies and CAA-induced microhemorrhages using RNA in situ hybridization, histology and digital spatial profiling in an Alzheimer's disease (AD) mouse model of microhemorrhage.ResultsIn the present study, we have demonstrated that bapineuzumab murine surrogate (3D6) induces profound vascular damage, leading to smooth muscle cell loss and blood–brain barrier (BBB) breakdown. In addition, digital spatial profiling (DSP) reveals that distinct immune responses contribute to vascular damage with peripheral immune responses and perivascular macrophage activation linked to smooth muscle cell loss and vascular fibrosis, respectively. Finally, RNA in situ hybridization identifies two distinct subsets of Trem2+ macrophages representing tissue-resident and monocyte-derived macrophages around vascular amyloid deposits. Overall, these findings highlight multifaceted roles of immune activation and vascular damage in driving the development of microhemorrhage.ConclusionsIn summary, our study has established a significant link between CAA-Aβ antibody immune complex formation, immune activation and vascular damage leading to smooth muscle cell loss. However, the full implications of this cascade on the development of microhemorrhages requires further exploration. Additional investigations are warranted to unravel the precise molecular mechanisms leading to microhemorrhage, the interplay of diverse immune populations and the functional roles played by various Trem2+ macrophage populations in response to Aβ immunotherapy.

YAP1 Status Defines Two Intrinsic Subtypes of LCNEC with Distinct Molecular Features and Therapeutic Vulnerabilities.

Large cell neuroendocrine carcinoma (LCNEC) is a high-grade neuroendocrine malignancy that, like small cell lung cancer (SCLC), is associated with the absence of druggable oncogenic drivers and dismal prognosis. In contrast to SCLC, however, there is little evidence to guide optimal treatment strategies, which are often adapted from SCLC and non-small cell lung cancer approaches. To better define the biology of LCNEC, we analyzed cell line and patient genomic data and performed IHC and single-cell RNA sequencing of core needle biopsies from patients with LCNEC and preclinical models. In this study, we demonstrate that the presence or absence of YAP1 distinguishes two subsets of LCNEC. The YAP1-high subset is mesenchymal and inflamed and is characterized, alongside TP53 mutations, by co-occurring alterations in CDKN2A/B and SMARCA4. Therapeutically, the YAP1-high subset demonstrates vulnerability to MEK- and AXL-targeting strategies, including a novel preclinical AXL chimeric antigen receptor-expressing T cell. Meanwhile, the YAP1-low subset is epithelial and immune-cold and more commonly features TP53 and RB1 co-mutations, similar to those observed in pure SCLC. Notably, the YAP1-low subset is also characterized by the expression of SCLC subtype-defining transcription factors, especially ASCL1 and NEUROD1, and as expected, given its transcriptional similarities to SCLC, exhibits putative vulnerabilities reminiscent of SCLC, including delta-like ligand 3 and CD56 targeting, as is with novel preclinical delta-like ligand 3 and CD56 chimeric antigen receptor-expressing T cells, and DNA damage repair inhibition. YAP1 defines distinct subsets of LCNEC with unique biology. These findings highlight the potential for YAP1 to guide personalized treatment strategies for LCNEC.

Relationship between human capital and entrepreneurship orientation from the intellectual capital perspective of innovative literacy

PurposeThis study measures the relationship between human capital and innovative literacy from the perspective of intellectual capital. For this purpose, the relationship between human capital and innovative literacy was first investigated to measure intellectual capital. Subsequently, the moderating effect of entrepreneurial orientation on the influence of innovative literacy on human capital was also analysed.Design/methodology/approachThis study analyses the relationship between innovative literacy, human capital and entrepreneurial orientation through structural equation modelling – the study sample comprised 457 participants in Türkiye.FindingsThe results suggest a positive relationship between human capital, a sub-component of intellectual capital and innovative literacy. Innovative literacy can influence intellectual capital and increase value. Our finding further confirms that entrepreneurial orientation has no moderating effect on the same relationship.Research limitations/implicationsDespite the observed correlation between IL and HC growth, this study had some limitations. First, the generalisability of the findings is limited because the sample was selected from individuals with a high level of education in Türkiye. Despite these limitations, this study has important theoretical and practical implications for developing countries. Türkiye is a developing country, and the selected sample is the most critical database in the country for an Innovative Literacy Scale. However, future research could focus on whether there is a potential source of bias and collect and compare data from heterogeneous workers. In addition, research on existing research frameworks in other countries may consider varying levels of education and business sectors. This research aims to be a pioneering initiative towards the advancement of IL. The question of whether IL should be considered equivalent to or a subset of HC, which has been previously proposed as a dimension of IC, can be clarified through a thorough examination of what IL means.Practical implicationsIn a theoretical framework, transforming human capital into value through innovations derived from innovative literacy activities will significantly increase the company's intellectual capital. Organizations in which innovative literacy play an important role achieve organizational goals, strengthen commitment and contribute to sustainability through the emergence of new potential innovative individuals. This research also contributes significantly to the existing literature. Initially regarding theoretical implications, this study examines the concept of innovative literacy in the existing literature on intellectual capital, human capital and entrepreneurial orientation. Additionally, this study offers a new perspective on intellectual capital.Social implicationsThe findings of this research also provide managerial outcomes. Initially, the assessment of concepts, research and development capabilities and efficient knowledge management are indicators of innovative literacy proficiency at the individual level. Human capital is a subcomponent of intellectual capital and refers to knowledge, skills and experience. Innovative and literate team members should be developed in order to strengthen the intellectual capital structure of an organization.Originality/valueThis study contributes to understanding innovative literacy from an intellectual capital perspective using the Innovative Literacy Scale to reveal important dimensions that influence innovative literacy. Using a measurement tool with new sub-dimensions not included in the extant literature on intellectual capital is unique. This study suggests that scholars should include innovative literacy – a distinct subset of intellectual capital – in their body of knowledge on human capital. Our findings have the potential to help meet the needs of human resource departments, researchers, educational institutions, public institutions and enterprises.

The Prevalence and Prognostic Implications of BRAF K601E Mutations in Thyroid Neoplasms: A Systematic Review and Meta-Analysis.

Activating mutations in the BRAF oncogene occur in 45% of papillary thyroid carcinomas (PTCs). Though less studied, K601E may identify a clinically distinct subset of thyroid neoplasms. A bioinformatics assessment was conducted using the COSMIC database and in silico data analysis. A systematic search was conducted through August 2024 to identify studies reporting BRAF mutation in thyroid neoplasms. Pooled prevalence, histopathological subtype distribution, extrathyroidal extension, lymph node metastasis, recurrence, and survival were extracted/analyzed from 32 studies (13 191 patients). In the COSMIC database, BRAF K601E was found in various tissue types but mainly in the thyroid. In silico data analysis revealed a structural and functional basis for differences between K601E and V600E. Upon systematic review, the BRAF K601E mutation was identified in 2.8% of PTCs compared to 22% with V600E. The stratified analysis revealed geographical differences, with higher rates in Italy (5.23%) and the United States of America (3.31%). The K601E mutant was enriched for follicular-patterned variants like NIFTP (11.2% of cases). Meta-analysis demonstrated significantly reduced extrathyroidal extension for K601E versus V600E mutants (RR = 0.22, 95% CI = 0.10-0.50, p = 0.0003). K601E-mutated neoplasms could be a unique clinicopathological entity associated with low-risk histology and reduced extrathyroidal extension, consistent with a more indolent course than V600E mutants. Although detecting K601E may potentially guide conservative management, further prospective studies are needed.

Embryonic macrophages support endocrine commitment during human pancreatic differentiation

Organogenesis is a complex process that relies on a dynamic interplay between extrinsic factors originating from the microenvironment and tissue-specific intrinsic factors. For pancreatic endocrine cells, the local niche consists of acinar and ductal cells as well as neuronal, immune, endothelial, and stromal cells. Hematopoietic cells have been detected in human pancreas as early as 6 post-conception weeks, but whether they play a role during human endocrinogenesis remains unknown. To investigate this, we performed single-nucleus RNA sequencing (snRNA-seq) of the second-trimester human pancreas and identified a wide range of hematopoietic cells, including two distinct subsets of tissue-resident macrophages. Leveraging this discovery, we developed a co-culture system of human embryonic stem cell-derived endocrine-macrophage organoids to model their interaction invitro. Here, we show that macrophages support the differentiation and viability of endocrine cells invitro and enhance tissue engraftment, highlighting their potential role in tissue engineering strategies for diabetes.

CCL21 Induces Plasmacytoid Dendritic Cell Migration and Activation in a Mouse Model of Glioblastoma

Dendritic cells (DCs) are professional antigen-presenting cells that are traditionally divided into two distinct subsets: myeloid DCs (mDCs) and plasmacytoid DCs (pDCs). pDCs are known for their ability to secrete large amounts of cytokine type I interferons (IFN- α). In our previous work, we have demonstrated that pDC infiltration promotes glioblastoma (GBM) tumor immunosuppression through decreased IFN-α secretion via TLR-9 signaling and increased suppressive function of regulatory T cells (Tregs) via increased IL-10 secretion, resulting in poor overall outcomes in mouse models of GBM. Further dissecting the overall mechanism of pDC-mediated GBM immunosuppression, in this study, we identified CCL21 as highly upregulated by multiple GBM cell lines, which recruit pDCs to tumor sites via CCL21-CCR7 signaling. Furthermore, pDCs are activated by CCL21 in the GBM microenvironment through intracellular signaling of β-arrestin and CIITA. Finally, we found that CCL21-treated pDCs directly suppress CD8+ T cell proliferation without affecting regulatory T cells (Tregs) differentiation, which is considered the canonical pathway of immunotolerant regulation. Taken together, our results show that pDCs play a multifaced role in GBM immunosuppression, and CCL21 could be a novel therapeutic target in GBM to overcome pDC-mediated immunosuppression.

Bisphosphonate salts as covalent and non-covalent task-specific ionic liquid synthesis

Functionalized ionic liquids, commonly referred to as task-specific ionic liquids (TSILs), represent a distinct subset within the realm of ILs. They stand out by having a functional group covalently bonded to either the cationic or the anionic counterpart of the ionic liquid. These tailored modifications confer specific properties to TSILs, making them well-suited for various applications, including catalysis, liquid–liquid extraction, and synthesis. Notably, they also find relevance in the field of nanomaterials. In this paper, we delineate the synthetic pathway for TSILs featuring imidazolinium or pyridinium cores functionalized with a bisphosphonate unit. Furthermore, we provide detailed insights into the green synthesis of imidazolinium salts constituted by a bisphosphonate moiety as the counterion. These innovative TSILs, characterized by a bisphosphonate group, pave the way for a new avenue in the selective complexation of strategic metals and the development of new drugs. 1 This underscores their potential utility in strategic metal recovery by extraction and related endeavors.

FGFR3::TACC3 fusions in head and neck carcinomas: a study of nine cases highlighting phenotypic heterogeneity, frequent HPV association, and a morphologically distinct subset in favor of a putative entity.

The FGFR3::TACC3 fusion has been reported in subsets of diverse cancers including urothelial and squamous cell carcinomas (SCC). However, the morphology of FGFR3::TACC3-positive head and neck carcinomas has not been well studied and it is unclear if this fusion represents a random event, or if it might characterize a morphologically distinct tumor type. We describe nine FGFR3::TACC3 fusion-positive head and neck carcinomas affecting six males and three females aged 38 to 89years (median, 59). The tumors originated in the sinonasal tract (n = 4), parotid gland (n = 2), and one case each in the oropharynx, submandibular gland, and larynx. At last follow-up (9-21months; median, 11), four patients developed local recurrence and/or distant metastases, two died of disease at 11 and 12months, one died of other cause, one was alive with disease, and two were disease-free. Three of six tumors harboredhigh risk oncogenic HPV infection (HPV33, HPV18, one unspecified). Histologically, three tumors revealed non-keratinizing transitional cell-like or non-descript morphology with variable mixed inflammatory infiltrate reminiscent of mucoepidermoid or DEK::AFF2 carcinoma (all were HPV-negative), and three were HPV-associated (all sinonasal) with multiphenotypic (1) and non-intestinal adenocarcinoma (2) pattern, respectively. One salivary gland tumor showed poorly cohesive large epithelioid cells with prominent background inflammation and expressed AR and GATA3, in line with a possible salivary duct carcinoma variant. Two tumors were conventional SCC. Targeted RNA sequencing revealed an in-frame FGFR3::TACC3 fusion in all cases. This series highlights heterogeneity of head and neck carcinomas harboring FGFR3::TACC3 fusions, which segregates into three categories: (1) unclassified HPV-negative category, morphologically distinct from SCC and other entities; (2) heterogeneous group of HPV-associated carcinomas; and (3) conventional SCC. A driver role of the FGFR3::TACC3 fusion in the first category (as a potential distinct entity)remains to be further studied. In the light of available FGFR-targeting therapies, delineation of these tumors and enhanced recognition is recommended.

The Complex Immune Cell Composition and Cellular Interaction in the Alveolar Compartment of Patients with Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is characterized by protein rich edema due to alveolar-capillary barrier dysfunction caused by inflammatory processes. Currently, our understanding of the inflammatory response in patients with ARDS is mainly based on assessment of the systemic compartment and preclinical studies. Investigations into the intricate network of immune cells and their critical functions in the alveolar compartment remain limited. However, with recent improvements in single cell analyses, our comprehensive understanding of the interactions between immune cells in the lungs has improved. In this review, we summarize the current knowledge about the cellular composition and interactions of different immune cell types within the alveolar space of patients with ARDS. Neutrophils and macrophages are the predominant immune cells in the alveolar space of ARDS patients. Yet, all immune cells present, including lymphocytes, participate in complex interactions, coordinate recruitment, modulate the lifespan and control apoptosis through various signaling pathways. Moreover, the cellular composition of alveolar immune cells is associated with clinical outcomes of ARDS patients. In conclusion, this synthesis advances our understanding of ARDS immunology, emphasizing the crucial role of immune cells within the alveolar space. Associations between cellular composition and clinical outcomes highlight the significance of exploring distinct alveolar immune cell subsets. Such exploration holds promise for uncovering novel therapeutic targets in ARDS pathophysiology, presenting avenues for enhancing clinical management and treatment strategies for ARDS patients. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

A modular circuit coordinates the diversification of courtship strategies

Mate recognition systems evolve rapidly to reinforce the reproductive boundaries between species, but the underlying neural mechanisms remain enigmatic. Here we leveraged the rapid coevolution of female pheromone production and male pheromone perception in Drosophila1,2 to gain insight into how the architecture of mate recognition circuits facilitates their diversification. While in some Drosophila species females produce unique pheromones that act to arouse their conspecific males, the pheromones of most species are sexually monomorphic such that females possess no distinguishing chemosensory signatures that males can use for mate recognition3. We show that Drosophila yakuba males evolved the ability to use a sexually monomorphic pheromone, 7-tricosene, as an excitatory cue to promote courtship. By comparing key nodes in the pheromone circuits across multiple Drosophila species, we reveal that this sensory innovation arises from coordinated peripheral and central circuit adaptations: a distinct subpopulation of sensory neurons has acquired sensitivity to 7-tricosene and, in turn, selectively signals to a distinct subset of P1 neurons in the central brain to trigger courtship. Such a modular circuit organization, in which different sensory inputs can independently couple to parallel courtship control nodes, may facilitate the evolution of mate recognition systems by allowing novel sensory modalities to become linked to male arousal. Together, our findings suggest how peripheral and central circuit adaptations can be flexibly coordinated to underlie the rapid evolution of mate recognition strategies across species.

Tumor-Associated Macrophages as Major Immunosuppressive Cells in the Tumor Microenvironment

Within the tumor microenvironment, myeloid cells constitute a dynamic immune population characterized by a heterogeneous phenotype and diverse functional activities. In this review, we consider recent literature shedding light on the increasingly complex biology of M2-like immunosuppressive tumor-associated macrophages (TAMs), including their contribution to tumor cell invasion and metastasis, stromal remodeling (fibrosis and matrix degradation), and immune suppressive functions, in the tumor microenvironment (TME). We also review the development of promising therapeutic approaches to target these populations in cancers. The expanding knowledge of distinct subsets of immunosuppressive TAMs, and their contributions to tumorigenesis and metastasis, has sparked significant interest among researchers regarding the therapeutic potential of TAM depletion or phenotypic modulation. This review delineates the involvement of M2-like TAM subsets in cancer development and metastasis, while also delving into the intricate signaling mechanisms underlying the polarization of diverse macrophage phenotypes, their plasticity, and therapeutic implications.

Tuft cells act as regenerative stem cells in the human intestine

In mice, intestinal tuft cells have been described as a long-lived, postmitotic cell type. Two distinct subsets have been identified: tuft-1 and tuft-2 (ref. 1). By combining analysis of primary human intestinal resection material and intestinal organoids, we identify four distinct human tuft cell states, two of which overlap with their murine counterparts. We show that tuft cell development depends on the presence of Wnt ligands, and that tuft cell numbers rapidly increase on interleukin-4 (IL-4) and IL-13 exposure, as reported previously in mice2–4. This occurs through proliferation of pre-existing tuft cells, rather than through increased de novo generation from stem cells. Indeed, proliferative tuft cells occur in vivo both in fetal and in adult human intestine. Single mature proliferating tuft cells can form organoids that contain all intestinal epithelial cell types. Unlike stem and progenitor cells, human tuft cells survive irradiation damage and retain the ability to generate all other epithelial cell types. Accordingly, organoids engineered to lack tuft cells fail to recover from radiation-induced damage. Thus, tuft cells represent a damage-induced reserve intestinal stem cell pool in humans.