Origin Of Heterogeneity Research Articles

EPCO-35. SINGLE-CELL RNA-SEQ OF PEDIATRIC EPENDYMOMA REVEALS PROGNOSTIC IMPACT OF IMPAIRED NEURONAL-GLIAL FATE SPECIFICATION

Abstract Ependymoma represents a heterogeneous disease affecting the entire neuraxis. Extensive molecular profiling efforts have identified molecular ependymoma subgroups based on DNA methylation. However, the intratumoral heterogeneity and developmental origins of these groups are only partially understood, and effective treatments are still lacking for about 50% of patients with high-risk tumors. We interrogated the cellular architecture of ependymoma using single cell/single nucleus RNA-sequencing to analyze 24 tumor specimens across major molecular subgroups and anatomic locations. We additionally analyzed ten patient-derived ependymoma cell models and two patient-derived xenografts (PDXs). Interestingly, we identified an analogous cellular hierarchy across all ependymoma groups, originating from undifferentiated neural stem cell-like populations towards different degrees of impaired differentiation states comprising neuronal precursor-like, astro-glial-like, and ependymal-like tumor cells. While prognostically favorable ependymoma groups predominantly harbored differentiated cell populations, aggressive groups were enriched for undifferentiated subpopulations. Projection of transcriptomic signatures onto an independent bulk RNA-seq cohort stratified patient survival even within known molecular groups, thus refining the prognostic power of DNA methylation-based profiling. Furthermore, we identified novel potentially druggable targets such as IGF- and FGF-signaling within poorly prognostic transcriptional programs. Ependymoma-derived cell models/PDXs widely recapitulated the transcriptional programs identified within fresh tumors and are leveraged to validate identified target genes in functional follow-up analyses. Taken together, our analyses reveal a developmental hierarchy and transcriptomic context underlying the biologically and clinically distinct behavior of ependymoma groups. The newly characterized cellular states and underlying regulatory networks could serve as basis for future therapeutic target identification and reveal biomarkers for clinical trials.

Heterogeneous Subcellular Origin of Exosome-Mimetic Nanovesicles Engineered from Cells.

Cell-engineered nanovesicles (CNVs) are considered as an alternative to exosomes, because they can be produced efficiently on a large scale and have been successfully reported in several applied research studies. However, CNVs may originate from various organelles, i.e., some of them may cause adverse effects on recipient cells, and their origin has not yet been identified. In this study, we air-sprayed human embryonic kidney 293 (HEK293) cells into lipid-bilayer CNVs. To identify the subcellular origin of the CNVs, we prepared nine different HEK293 cell lines by transfection with organelle-specific fluorescent protein plasmids that target the plasma membrane, peroxisome, lysosome, early endosome, late endosome, nucleus, mitochondrion, Golgi apparatus, and endoplasmic reticulum. The origin of CNVs were identified by measuring fluorescence expressions for organelle-specific markers using fluorescence nanoparticle tracking analysis (NTA). In the results, we found that CNVs derived from the plasma membrane constituted the largest portion, but CNVs derived from the other organelles comprised a non-negligible portion as well. This information will be useful to guide advanced research on outer membrane vesicles and exosome-mimetic nanovesicles engineered from cells.

Prognostic value of preoperative lymphocyte-related systemic inflammatory biomarkers in upper tract urothelial carcinoma patients treated with radical nephroureterectomy: a systematic review and meta-analysis

BackgroundGrowing evidence shows that the preoperative lymphocyte-related systemic inflammatory biomarkers are associated with the prognosis of patients with upper tract urothelial carcinoma (UTUC). These markers include neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR). However, these findings are inconsistent, and the prognostic significance of these biomarkers is unclear. Moreover, the currently available prognostic indicators do not precisely predict the outcome of UTUC patients. This motivated us to investigate the prognostic values of NLR, PLR, and MLR in UTUC patients treated with radical nephroureterectomy (RNU).MethodsWe prospectively registered this in PROSPERO (CRD42020186531). We performed a comprehensive literature search of the PubMed, Web of Science, EMBASE, and Cochrane Library databases to identify the eligible studies evaluating the prognostic values of preoperative NLR, PLR, and MLR. Hazard ratios with 95% confidence intervals of overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS), recurrence-free survival (RFS), metastasis-free survival (MFS), and progression-free survival (PFS) were extracted from the multivariate analyses and analyzed with fixed or random effects models when applicable. Heterogeneity among the studies was evaluated using Cochran’s Q test and I2 statistic. Sensitivity and subgroup analyses were conducted to explore the origin of heterogeneity. The Newcastle-Ottawa Scale (NOS) was applied to assess the quality of each enrolled study. Publication bias was determined using funnel plots together with Egger’s tests. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to evaluate the quality of the evidence.ResultsOverall, we included 10,339 UTUC patients from twenty-five retrospective studies. The results indicated that elevated preoperative NLR, PLR, and MLR were significantly associated with worse OS, CSS, DFS/RFS/MFS, and PFS in the UTUC patients undergoing RNU. Furthermore, the results of sensitivity and subgroup analyses demonstrated the rationality and reliability of the results.ConclusionsThe present meta-analysis demonstrated a significant association between elevated preoperative NLR, PLR, and MLR and poor prognosis in patients with surgically treated UTUC. Hence, lymphocyte-related systemic inflammatory biomarkers, in conjunction with clinicopathological factors, molecular markers, and other prognostic indicators, could be helpful to determine the primary treatment strategies and to design individualized follow-up plans for UTUC patients.

Origin of structural heterogeneity in Zr-Co-Al metallic glasses from the point of view of liquid structures

To clarify the origin of structural heterogeneity in metallic glasses (MGs), liquid structures upon cooling of Zr-Co-Al alloys were simulated. Being different from Zr10Co85Al5 alloy, the first peak of pair distribution functions (PDFs) for Zr65Co30Al5 alloy exhibits a splitting behavior, which is attributed to the competition between Co-and Zr-centered clusters. The coordination numbers and chemical short-range order (SRO) analysis show that the chemical structural heterogeneity also governs the formation of Zr65Co30Al5 MG. Bond pair analysis reveals the prominence of bond pairs with five-fold symmetry for both MGs, but bond pairs in Zr65Co30Al5 MG exhibit noticeable six-fold symmetric stability. Voronoi polyhedron analysis further confirms the formation of strong chemical SROs in Zr65Co30Al5 MG. Dynamic mechanical experiments (DMA) prove the existence of structural heterogeneity, while Zr65Co30Al5 MG with more pronounced (chemical) structural heterogeneity displays larger ductility. The present work may provide a new insight into the origin of structural heterogeneity in MGs.

Bridging sensory and language theories of dyslexia: Toward a multifactorial model.

Competing theories of dyslexia posit that reading difficulties arise from impaired visual, auditory, phonological, or statistical learning mechanisms. Importantly, many theories posit that dyslexia reflects a cascade of impairments emanating from a single “core deficit”. Here we report two studies evaluating core deficit and multifactorial models. In Study 1, we use publicly available data from the Healthy Brain Network to test the accuracy of phonological processing measures for predicting dyslexia diagnosis and find that over 30% of cases are misclassified (sensitivity = 66.7%; specificity = 68.2%). In Study 2, we collect a battery of psychophysical measures of visual motion processing and standardized measures of phonological processing in 106 school‐aged children to investigate whether dyslexia is best conceptualized under a core‐deficit model, or as a disorder with heterogenous origins. Specifically, by capitalizing on the drift diffusion model to analyze performance on a visual motion discrimination experiment, we show that deficits in visual motion processing, perceptual decision‐making, and phonological processing manifest largely independently. Based on statistical models of how variance in reading skill is parceled across measures of visual processing, phonological processing, and decision‐making, our results challenge the notion that a unifying deficit characterizes dyslexia. Instead, these findings indicate a model where reading skill is explained by several distinct, additive predictors, or risk factors, of reading (dis)ability.

LA-ICP-MS imaging in the geosciences and its applications to geochronology

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) mapping is a rapidly expanding field in the geosciences because of the wealth of spatial information it provides on the petrogenesis of igneous, metamorphic and sedimentary rocks and ore mineral formation. The technique has also opened many new applications in forensics, archaeology and the imaging of trace metals in biological tissues. Instrumentation advances in both LA and ICP-MS systems now permit precise isotopic analysis with laser spot sizes of <10 μm and sub-ppm detections limits. In particular LA-quadrupole (Q)-ICP-MS systems facilitate mapping of large numbers of elements across nearly the entire mass range of the periodic table. A range of key applications in petrogenesis studies and in the fields of environmental and biological sciences is reviewed. Furthermore, technical considerations including a practical guide for setting up LA-ICP-MS multi-element mapping experiments and the latest innovations in dedicated data reduction and image processing packages for the visualization, interrogation and extraction of quantitative data from LA-ICP-MS maps are discussed, with particular emphasis placed on quadrupole systems. A key issue is imaging artefacts (spectral skew) caused by interaction between the laser repetition rate and the total sweep cycle time, particularly when coupling a sequential Q-ICP-MS analyser to modern low dispersion (fast-washout) LA cells. Running at high repetition rates is recommended for low-dispersion cells as it enables faster scanning while minimizing temporal variations in signal intensity caused by pulsing of the laser. Advances in LA-ICP-MS instrumentation and methodologies (data processing, visualization and extraction) have enabled simultaneous acquisition of compositional and U-Pb age information at high-spatial resolution which has great potential in geochronological studies. Formation histories of complex polyphase accessory minerals such as zircon, titanite or monazite, where discrete age domains are often linked with specific rock-forming processes and their physical conditions (i.e. U-Pb petrochronology), are now directly accessible. Moreover, fine-scale processes affecting the U-Pb systematics of accessory minerals can be constrained when LA-ICP-MS mapping is combined with other textural (e.g. CL or Raman) imaging techniques. U-Pb analysis of materials with variable initial Pb concentrations and/or heterogeneous genetic origin such as carbonates also benefit from such a mapping approach as areas with sufficient spread in 238U/204Pb ratio (μ) can be targeted, while simultaneous imaging of diagnostic trace elements allows identification and exclusion of zones affected by alteration or detrital contamination. The quasi-simultaneous detection offered by LA-time-of-flight (TOF)-ICP-MS allows rapid multi-element analysis of very fast transient signals (i.e. laser ablation imaging in low dispersion laser ablation cells). The approach is ideally suited to 2D and 3D imaging of biological and geological materials and will likely replace LA-Q-ICP-MS for such applications once more routinely available.

Tackling Antibiotic Resistance with Compounds of Natural Origin: A Comprehensive Review.

Drug-resistant bacteria pose a serious threat to human health worldwide. Current antibiotics are losing efficacy and new antimicrobial agents are urgently needed. Living organisms are an invaluable source of antimicrobial compounds. The antimicrobial activity of the most representative natural products of animal, bacterial, fungal and plant origin are reviewed in this paper. Their activity against drug-resistant bacteria, their mechanisms of action, the possible development of resistance against them, their role in current medicine and their future perspectives are discussed. Electronic databases such as PubMed, Scopus and ScienceDirect were used to search scientific contributions until September 2020, using relevant keywords. Natural compounds of heterogeneous origins have been shown to possess antimicrobial capabilities, including against antibiotic-resistant bacteria. The most commonly found mechanisms of antimicrobial action are related to protein biosynthesis and alteration of cell walls and membranes. Various natural compounds, especially phytochemicals, have shown synergistic capacity with antibiotics. There is little literature on the development of specific resistance mechanisms against natural antimicrobial compounds. New technologies such as -omics, network pharmacology and informatics have the potential to identify and characterize new natural antimicrobial compounds in the future. This knowledge may be useful for the development of future therapeutic strategies.

Marital status, partner acknowledgment of paternity, and neighborhood influences on smoking during first pregnancy: findings across race/ethnicity in linked administrative and census data

BackgroundImproving prediction of cigarette smoking during pregnancy (SDP), including differences by race/ethnicity and geography, is necessary for interventions to achieve greater and more equitable SDP reductions. MethodsUsing individual-level data on singleton first births, 2010-2017 (N = 182,894), in a US state with high SDP rates, we predicted SDP risk as a function of reproductive partner relationship (marital status, paternity acknowledgement), maternal and residential census tract sociodemographics, and census tract five-year SDP rate. ResultsSDP prevalence was 12.7% (white non-Hispanics, WNH), 6.8% (Black/African Americans, AA), 19.5% (Native American, NA), 4.7% (Hispanic, H), and 2.8% (Asian, AS). In WNH and AA, with similar trends in other groups, after adjustment for non-linear effects of maternal age and education and for census tract risk-factors, there was a consistent risk-ordering of SDP rates by reproductive partner relationship: married/with paternity acknowledged < unmarried/acknowledged < unmarried/unacknowledged < married/unacknowledged. Associations with census tract SDP rate, adjusted for maternal and census tract sociodemographics, were stronger for AA and H (OR 2.65-2.67) than for NA (OR = 1.91), WNH (OR = 1.75), or AS (NS). AA SDP was increased in tracts having a higher proportion of WNH residents and was reduced in comparison with WNH at every combination of age, education and partner relationship. ConclusionsInattention to differences by race/ethnicity may obscure SDP risk factors. Despite marked race/ethnic differences in unmarried-partner cohabitation rates, failure to acknowledge paternity emerged as an important and consistent risk-predictor. Census-tract five-year SDP rates have heterogeneous origins, but the association of AA SDP risk with increased racial heterogeneity suggests an important influence of neighbor risk behaviors.

Abstract 4154: The emerging clinical relevance of genomic profiling medicine in neuroendocrine tumors

Abstract Neuroendocrine tumors (NET) can develop everywhere in the body which have heterogeneous origins and complicated histology. Thus, genomic profiling becomes inevitable to overcome the disease's complexity through the determination of hereditary predisposition and treatment actionability. For this purpose, next generation sequencing as the most reliable methodology for both germ-line and somatic studies, can be utilized in clinical oncology as we present in this study which liquid biopsy, FFPE tissue and peripheral blood samples in terms of actionability and predisposition for various types of neuroendocrine tumors have been analyzed. A customized multi-gene panel (consists of SDHB, SDHC, CDC73, CASR, PDGFRA, SDHA, RET, SDHAF2, MEN1, SDHD, MAX and PRKAR1A genes) have been used from 3 liquid biopsy, 6 FFPE tissue and 26 peripheral blood samples of 35 distinctive NET patients. Quality control and bioinformatics analysis were performed using QCI-Analyze and QCI-Interpret. Three liquid biopsy and 6 FFPE samples were evaluated for somatic analysis while 26 peripheral blood samples were included in germ-line pipeline. Five (55.6%) of the 9 patients that were studied for somatic changes carry actionable mutations related to therapy sensitivity. While through the germ-line studies, we observed 50% positivity rate for disease predisposition in germ-line studies with sixteen variants in 13 patients. Variant classification criteria were given in details in Table 1 according to the ACMG (American College of Medical Genetics) Standards and Guidelines. Genomic profiling medicine as the emerging area of clinical oncology in this era becomes crucial for disease and patient management properly in terms of a precise approach especially in rare diseases including the rare cancers such as NETs. Most notably, our study emphasizes the relevance of distinctive biological samples in the use of genetic testing for cancer care. Table 1.Implemented variant classification criteria of detected germ-line mutations in our study.PatientGeneVariant (amino acid change)ACMG criteria (doi: 10.1038/gim.2015.30)P1KITM541L (Heterozygote)PM2, BP4, BP6P2SDHCR72H (Heterozygote)PM1, PM2, PP3P3SDHBG19FS*57 (Heterozygote)PVS1, PM1, PM2P4PDGFRAS66R (Heterozygote)PM2, BP1, BP4P5RETA96V (Heterozygote)PM2, PP2, BP4P6KITR946* (Heterozygote)PM2, PP2, BP4P7RETG691S (Heterozygote)PP2, BA1, BS3, BP4P8RETG691S (Heterozygote)PP2, BA1, BS3, BP4P9RETG691S (Heterozygote)PP2, BA1, BS3, BP4P10RETG691S (Heterozygote)PP2, BA1, BS3, BP4P11RETG691S (Heterozygote)PP2, BA1, BS3, BP4KITA431E (Heterozygote)PM1, PM2, BP4P12RETG691S (Heterozygote)PP2, BA1, BS3, BP4RETA1051V (Heterozygote)PM1, PP2, PP3P13KITM541L (Heterozygote)PM2, BP4, BP6SDHDG12S (Heterozygote)PP2, BS1, BS3, BP4, BP6 Citation Format: Ozge Sonmezler, Isa B. Guney, Cem Mujde, Atil Bisgin. The emerging clinical relevance of genomic profiling medicine in neuroendocrine tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4154.

Heterogeneous origins and functions of mouse skeletal muscle-resident macrophages

Tissue-resident macrophages can originate from embryonic or adult hematopoiesis. They play important roles in a wide range of biological processes including tissue remodeling during organogenesis, organ homeostasis, repair following injury, and immune response to pathogens. Although the origins and tissue-specific functions of resident macrophages have been extensively studied in many other tissues, they are not well characterized in skeletal muscle. In the present study, we have characterized the ontogeny of skeletal muscle-resident macrophages by lineage tracing and bone marrow transplant experiments. We demonstrate that skeletal muscle-resident macrophages originate from both embryonic hematopoietic progenitors located within the yolk sac and fetal liver as well as definitive hematopoietic stem cells located within the bone marrow of adult mice. Single-cell-based transcriptome analyses revealed that skeletal muscle-resident macrophages are distinctive from resident macrophages in other tissues as they express a distinct complement of transcription factors and are composed of functionally diverse subsets correlating to their origins. Functionally, skeletal muscle-resident macrophages appear to maintain tissue homeostasis and promote muscle growth and regeneration.

2006 – STEM CELL BASED HETEROGENEITY OF INTERFERON SIGNALING DURING HEMATOPOIETIC DEVELOPMENT

Inflammation has a great impact on an organism. In order to protect the hematopoietic system from exhaustion during pathogenic insult, heterogeneity in metabolic activity, gene expression patterns, and responsiveness to cytokines such as interferons (IFN) have been revealed. Yet, how this diversity in the system is generated and maintained remains poorly understood. Here, we show that intra-cell type heterogeneity in expression of IFN-stimulated genes (ISGs) is already established at the level of the hematopoietic stem cell (HSC). Transplantation experiments using different reporter mouse models indicated stable inheritance of the ISG expression to downstream progeny. Single cell transplantation experiments of wild type (WT) HSCs supported these findings, proposing a stable inheritance of IFN signaling heterogeneity from HSCs to mature blood cells. Next, we investigated the origin of ISG heterogeneity. From a first streak of primitive hematopoiesis early in embryonal development to the expansion of definitive HSCs in the fetal liver, HSCs pass through a number of embryonal sites. Fetal liver HSCs at E13.5 already showed ISG expression heterogeneity, comparable to the adult stem cells. Yet, at earlier time points during development the degree of ISG expression was depending on the time point and organ the cells were isolated from. In both WT and reporter mice the highest degree of ISG expression was found in the placenta. These data suggest an important role for the placenta during establishment of the heterogeneity. Thus, our data suggest that heterogeneity of IFN signaling in the hematopoietic system, stably inherited from stem cells to progeny, is already established early during hematopoietic development. Uncovering the origin and function of the heterogeneity will have far-reaching implications for HSC biology in health, disease, and upon infection.

Large iron isotope variation in the eastern Pacific mantle as a consequence of ancient low-degree melt metasomatism

Studies of mid-ocean ridge basalts (MORB) have revealed a heterogeneous asthenospheric mantle in chemical elements and radiogenic isotopes. Here we report that MORB mantle is also heterogeneous in Fe isotopes through studying the glass samples from seamounts flanking the northern East Pacific Rise between 5° and 15°N. These samples show large Fe isotope variation with δ56Fe values (+0.03‰ to +0.36‰) exceeding the known range of MORB (+0.05‰ to +0.17‰). Such highly varied δ56Fe values cannot be well explained by seafloor alteration, fractional crystallization or partial melting processes, but instead require a source mantle significantly heterogeneous in Fe isotope compositions. Importantly, the δ56Fe values of these basalts correlate significantly with major and trace elements and Sr-Nd-Pb-Hf radiogenic isotopes, reflecting melting-induced mixing of a two-component mantle with the enriched component having heavy Fe isotope compositions dispersed as physically distinct domains in the depleted mantle matrix. The major and trace element characteristics of the enriched mantle component, as inferred from these basalts, are consistent with a low-degree melting origin. Such low-degree melts with heavy Fe isotope compositions most likely formed at sites such as the lithosphere-asthenosphere boundary beneath ocean basins, which can metasomatize the overlying oceanic lithosphere by crystallizing dikes/veins of garnet pyroxenite lithologies. Recycling of these dikes/veins with isotopically heavier Fe can readily contribute to the Fe isotope heterogeneity in the MORB mantle. However, the extremely high primitive δ56Fe values of the two alkali basalts (up to 0.34‰) require an enriched source component with unusually high δ56Fe values. We suggest that partial melts from the recycled dikes/veins of garnet pyroxenite lithologies can react with the ambient peridotitic mantle and generate a secondary garnet pyroxenite with heavier Fe isotope compositions than, but similar radiogenic isotope compositions as its precursor. Melting-induced mixing between these garnet pyroxenites (recycled and newly formed) and depleted mantle matrix can readily explain the compositional variations in elements, radiogenic isotopes and Fe isotopes observed in these seamount lavas. These new data and correlated variations offer a new dimension for understanding the origin of mantle chemical and isotopic heterogeneity in the context of chemical differentiation of the Earth.

Recent Experiments Support a Microemulsion Origin of Plasma Membrane Domains: Dependence of Domain Size on Physical Parameters.

It is widely, but not universally, believed that the lipids of the plasma membrane are not uniformly distributed, but that “rafts” of sphingolipids and cholesterol float in a “sea” of unsaturated lipids. The physical origin of such heterogeneities is often attributed to a phase coexistence between the two different domains. We argue that this explanation is untenable for several reasons. Further, we note that the results of recent experiments are inconsistent with this picture. However, they are quite consistent with an alternate explanation, namely, that the plasma membrane is a microemulsion of the two kinds of regions. To show this, we briefly review a simplified version of this theory and its phase diagram. We also explicate the dependence of the predicted domain size on four physical parameters. They are the energy cost of gradients in the composition, the spontaneous curvature of the membrane, its bending modulus and its surface tension. Taking values of the latter two from experiment, we obtain domain sizes for several different cell types that vary from 58 to 88 nm.

Pre-existing Cell States Control Heterogeneity of Both EGFR and CXCR4 Signaling.

CXCR4 and epidermal growth factor receptor (EGFR) represent two major families of receptors, G-protein coupled receptors and receptor tyrosine kinases, with central functions in cancer. While utilizing different upstream signaling molecules, both CXCR4 and EGFR activate kinases ERK and Akt, although single-cell activation of these kinases is markedly heterogeneous. One hypothesis regarding the origin of signaling heterogeneity proposes that intercellular variations arise from differences in pre-existing intracellular states set by extrinsic noise. While pre-existing cell states vary among cells, each pre-existing state defines deterministic signaling outputs to downstream effectors. Understanding causes of signaling heterogeneity will inform treatment of cancers with drugs targeting drivers of oncogenic signaling. We built a single-cell computational model to predict Akt and ERK responses to CXCR4- and EGFR-mediated stimulation. We investigated signaling heterogeneity through these receptors and tested model predictions using quantitative, live-cell time-lapse imaging. We show that the pre-existing cell state predicts single-cell signaling through both CXCR4 and EGFR. Computational modeling reveals that the same set of pre-existing cell states explains signaling heterogeneity through both EGFR and CXCR4 at multiple doses of ligands and in two different breast cancer cell lines. The model also predicts how phosphatidylinositol-3-kinase (PI3K) targeted therapies potentiate ERK signaling in certain breast cancer cells and that low level, combined inhibition of MEK and PI3K ablates potentiated ERK signaling. Our data demonstrate that a conserved motif exists for EGFR and CXCR4 signaling and suggest potential clinical utility of the computational model to optimize therapy.

Pancreatic Macrophages: Critical Players in Obesity-Promoted Pancreatic Cancer.

Obesity is a known risk factor for the development of pancreatic cancer, one of the deadliest types of malignancies. In recent years it has become clear that the pancreatic microenvironment is critically involved and a contributing factor in accelerating pancreatic neoplasia. In this context obesity-associated chronic inflammation plays an important role. Among several immune cells, macrophages have been shown to contribute to obesity-induced tissue inflammation. This review article summarizes the current knowledge about the role of pancreatic macrophages in early pancreatic cancer development. It describes the heterogenous origin and mixture of pancreatic macrophages, their role in pancreatic endocrine and exocrine pathology, and the impact of obesity on islet and stromal macrophages. A model is postulated, by which during obesity monocytes are recruited into the pancreas, where they are polarized into pro-inflammatory macrophages that drive early pancreatic neoplasia. This occurs in the presence of local inflammatory, metabolic, and endocrine signals. A stronger appreciation and more detailed knowledge about the role of macrophages in early pancreatic cancer development will lead to innovative preventive or interceptive strategies.

Intratumoral heterogeneity of hepatocellular carcinoma: From single-cell to population-based studies.

Hepatocellular carcinoma (HCC) is characterized by high heterogeneity in both intratumoral and interpatient manners. While interpatient heterogeneity is related to personalized therapy, intratumoral heterogeneity (ITH) largely influences the efficacy of therapies in individuals. ITH contributes to tumor growth, metastasis, recurrence, and drug resistance and consequently limits the prognosis of patients with HCC. There is an urgent need to understand the causes, characteristics, and consequences of tumor heterogeneity in HCC for the purposes of guiding clinical practice and improving survival. Here, we summarize the studies and technologies that describe ITH in HCC to gain insight into the origin and evolutionary process of heterogeneity. In parallel, evidence is collected to delineate the dynamic relationship between ITH and the tumor ecosystem. We suggest that conducting comprehensive studies of ITH using single-cell approaches in temporal and spatial dimensions, combined with population-based clinical trials, will help to clarify the clinical implications of ITH, develop novel intervention strategies, and improve patient prognosis.

Janus-Faced: Molecular Mechanisms and Versatile Nature of Renal Fibrosis.

Renal fibrosis is a major hallmark of CKD, regardless of the underlying etiology. In fibrosis development and progression, myofibroblasts play a pivotal role, producing extracellular matrix and interacting with various resident cells in the kidney. Over the past decade, the origin of myofibroblasts has been thoroughly investigated. Emerging evidence suggests that renal myofibroblasts originate from several cellular sources, including resident fibroblasts, pericytes, and bone marrow-derived cells. The contribution of resident fibroblasts is most crucial, and currently available data strongly suggest the importance of functional heterogeneity and plasticity of fibroblasts in kidney disease progression. Resident fibroblasts acquire distinct phenotypes based on their local microenvironment and exert multifactorial functions. For example, age-dependent alterations of renal fibroblasts make a significant contribution to the formation of tertiary lymphoid tissues, which promote local inflammation after injury in the aged kidney. In conjunction with fibrosis development, dysfunction of resident fibroblasts provokes unique pathologic conditions including renal anemia and peritubular capillary loss, both of which are major complications of CKD. Although renal fibrosis is considered detrimental in general, recent studies suggest it has beneficial roles, such as maintaining functional crosstalk with injured proximal tubular cells and supporting their regeneration. These findings provide novel insight into the mechanisms of renal fibrosis, which could be regarded as an adaptive process of kidney injury and repair. Precise understanding of the functional heterogeneity of resident fibroblasts and myofibroblasts has the potential to facilitate the development of novel therapeutics against kidney diseases. In this review, we describe the current perspective on the origin of myofibroblasts and fibroblast heterogeneity, with special emphasis on the dual aspects of renal fibrosis, both beneficial and detrimental, in CKD progression.

Single-Cell RNA-Seq Reveals Cellular Hierarchies and Impaired Developmental Trajectories in Pediatric Ependymoma

SummaryEpendymoma is a heterogeneous entity of central nervous system tumors with well-established molecular groups. Here, we apply single-cell RNA sequencing to analyze ependymomas across molecular groups and anatomic locations to investigate their intratumoral heterogeneity and developmental origins. Ependymomas are composed of a cellular hierarchy initiating from undifferentiated populations, which undergo impaired differentiation toward three lineages of neuronal-glial fate specification. While prognostically favorable groups of ependymoma predominantly harbor differentiated cells, aggressive groups are enriched for undifferentiated cell populations. The delineated transcriptomic signatures correlate with patient survival and define molecular dependencies for targeted treatment approaches. Taken together, our analyses reveal a developmental hierarchy underlying ependymomas relevant to biological and clinical behavior.

The newly proposed International Endocervical Adenocarcinoma Criteria and Classification and its relevance to cervical cytology screening assessed in a prospective 2-year study of 118 cases.

It is generally acknowledged that interobserver variability for the histological diagnosis of endocervical adenocarcinoma (EA) subtypes is suboptimal. The recently proposed International Endocervical Adenocarcinoma Criteria and Classification (IECC) system is based on the presence of associated human papilloma virus (HPV) infection. It recognises HPV-associated EAs and non-HPV-associated EAs. This prospective cytology-histology and molecular genetics-based study investigated the potential effect of IECC being applied to Papanicolaou (Pap) test with regard to the diagnostic accuracy of severe glandular lesions reported at least as adenocarcinoma in situ (AIS). Out of 118 liquid-based cytology Pap tests with AIS+ lesion, complete information on follow-up biopsy and HPV status was available in 51 cases. AIS and EA category correlated with histologically confirmed AIS/EA in 88.5% (23/26) and 70.5% (12/17) of cases, respectively. Interestingly, 93% (40/43) of cases diagnosed as AIS/EA were HPV positive and 7% (3/43) were HPV negative (originating in the cervix, endometrium and adnexa). Our findings suggest that this approach could possibly divide Pap tests containing severe glandular lesion into two groups: (a) robust diagnosis of HPV-associated EA and (b) non-HPV associated glandular lesions of heterogeneous origin, requiring further clinical preoperative diagnostic workup.

Medium- and long-range transport events of Alnus pollen in western Mediterranean.

Alnus pollen has been frequently detected in the atmosphere of different airborne sampling sites of Southern Spain. However, Alnus sp. populations are very scarce and fragmented in the area, being restricted to a few river valleys in the southwest, and other further away regions of the Iberian Peninsula. This leads to think that the airborne pollen detected could be mainly the result of a medium- or long-distant transport. So, the aim of this study was to characterize the annual patterns of airborne Alnus pollen detected at three different locations of Malaga province, as well as to determine its possible origin, the pollen dispersion potential of these Alnus isolated populations, and their possible reproductive connectivity. Pollen sampling was conducted by means of three Hirst-type volumetric pollen traps. Samples were mounted and counted following the recommendations of the Spanish Aerobiology Network and the European Aeroallergen Society. The possible pollen sources were detected by means of a combination of meteorological information and backward air trajectories analysis. A high inter-annual variability in the annual pollen integrals was found in all the stations, favouring certain meteorological conditions a long-range transport and, therefore, causing the high concentrations detected in some specific days. Alnus pollen seems to have a heterogeneous origin with prevalence of the long-distant transport, which would suggest a possible reproductive connection among distant populations.