Agile workflow for interactive analysis of mass cytometry data.

MOTIVATION: Single-cell proteomics technologies, such as mass cytometry, have enabled characterization of cell-to-cell variation and cell populations at a single-cell resolution. These large amounts of data, require dedicated, interactive tools for translating the data into knowledge. RESULTS: We present a comprehensive, interactive method called Cyto to streamline analysis of large-scale cytometry data. Cyto is a workflow-based open-source solution that automates the use of state-of-the-art single-cell analysis methods with interactive visualization. We show the utility of Cyto by applying it to mass cytometry data from peripheral blood and high-grade serous ovarian cancer (HGSOC) samples. Our results show that Cyto is able to reliably capture the immune cell sub-populations from peripheral blood and cellular compositions of unique immune- and cancer cell subpopulations in HGSOC tumor and ascites samples. AVAILABILITYAND IMPLEMENTATION: The method is available as a Docker container at https://hub.docker.com/r/anduril/cyto and the user guide and source code are available at https://bitbucket.org/anduril-dev/cyto. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

FUNGI: FUsioN Gene Integration toolset.

MOTIVATION: Fusion genes are both useful cancer biomarkers and important drug targets. Finding relevant fusion genes is challenging due to genomic instability resulting in a high number of passenger events. To reveal and prioritize relevant gene fusion events we have developed FUsionN Gene Identification toolset (FUNGI) that uses an ensemble of fusion detection algorithms with prioritization and visualization modules. RESULTS: We applied FUNGI to an ovarian cancer dataset of 107 tumor samples from 36 patients. Ten out of 11 detected and prioritized fusion genes were validated. Many of detected fusion genes affect the PI3K-AKT pathway with potential role in treatment resistance. AVAILABILITYAND IMPLEMENTATION: FUNGI and its documentation are available at https://bitbucket.org/alejandra_cervera/fungi as standalone or from Anduril at https://www.anduril.org. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Anduril 2: upgraded large-scale data integration framework.

SUMMARY: Anduril is an analysis and integration framework that facilitates the design, use, parallelization and reproducibility of bioinformatics workflows. Anduril has been upgraded to use Scala for pipeline construction, which simplifies software maintenance, and facilitates design of complex pipelines. Additionally, Anduril's bioinformatics repository has been expanded with multiple components, and tutorial pipelines, for next-generation sequencing data analysis. AVAILABILITYAND IMPLEMENTATION: Freely available at http://anduril.org. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Hyper-phosphorylation of Sequestosome-1 Distinguishes Resistance to Cisplatin in Patient Derived High Grade Serous Ovarian Cancer Cells.

Platinum-resistance is a major limitation to effective chemotherapy regimens in high-grade serous ovarian cancer (HGSOC). To better understand the mechanisms involved we characterized the proteome and phosphoproteome in cisplatin sensitive and resistant HGSOC primary cells using a mass spectrometry-based proteomic strategy. PCA analysis identified a distinctive phosphoproteomic signature between cisplatin sensitive and resistant cell lines. The most phosphorylated protein in cisplatin resistant cells was sequestosome-1 (p62/SQSTM1). Changes in expression of apoptosis and autophagy related proteins Caspase-3 and SQSTM1, respectively, were validated by Western blot analysis. A significant increase in apoptosis in the presence of cisplatin was observed in only the sensitive cell line while SQSTM1 revealed increased expression in the resistant cell line relative to sensitive cell line. Furthermore, site-specific phosphorylation on 20 amino acid residues of SQSTM1 was detected indicating a hyper-phosphorylation phenotype. This elevated hyper-phosphorylation of SQSTM1 in resistant HGSOC cell lines was validated with Western blot analysis. Immunofluoresence staining of s28-pSQSTM1 showed inducible localization to autophagosomes upon cisplatin treatment in the sensitive cell line while being constitutively expressed to autophagosomes in the resistant cell. Furthermore, SQSTM1 expression was localized in cancer cells of clinical high-grade serous tumors. Here, we propose hyper-phosphorylation of SQSTM1 as a marker and a key proteomic change in cisplatin resistance development in ovarian cancers by activating the autophagy pathway and influencing down-regulation of apoptosis.

Somatic MED12 Nonsense Mutation Escapes mRNA Decay and Reveals a Motif Required for Nuclear Entry.

MED12 is a key component of the transcription-regulating Mediator complex. Specific missense and in-frame insertion/deletion mutations in exons 1 and 2 have been identified in uterine leiomyomas, breast tumors, and chronic lymphocytic leukemia. Here, we characterize the first MED12 5' end nonsense mutation (c.97G>T, p.E33X) identified in acute lymphoblastic leukemia and show that it escapes nonsense-mediated mRNA decay (NMD) by using an alternative translation initiation site. The resulting N-terminally truncated protein is unable to enter the nucleus due to the lack of identified nuclear localization signal (NLS). The absence of NLS prevents the mutant MED12 protein to be recognized by importin-α and subsequent loading into the nuclear pore complex. Due to this mislocalization, all interactions between the MED12 mutant and other Mediator components are lost. Our findings provide new mechanistic insights into the MED12 functions and indicate that somatic nonsense mutations in early exons may avoid NMD.

Netrin-1-induced activation of Notch signaling mediates glioblastoma cell invasion.

Glioblastoma multiforme is an aggressively invasive human brain cancer, which lacks effective treatment. The axonal guidance protein, netrin-1, is overexpressed in glioblastoma tumor biopsies. In Matrigel invasion assays we observed that experimental overexpression of netrin-1 increased cell invasiveness and its downregulation decreased invasiveness. Using tandem affinity purification and mass spectrometry protein identification we found that netrin-1 forms a complex with both Notch2 and Jagged1. Recombinant netrin-1 colocalized with Jagged1 and Notch2 at the cell surface and was also present in the intracellular vesicles with Jagged1, but not with Notch2. Netrin-1 activated Notch signaling and subsequent glioblastoma cell invasion. Interestingly, the recombinant central domain of netrin-1 counteracted the effects of the full-length netrin-1: it inhibited glioblastoma cell invasion and Notch activation by retaining the Notch signaling complex at the cell surface. This finding may give rise to therapeutic applications. These results reveal a new mechanism leading to glioblastoma cell invasion, in which netrin-1 activates Notch signaling.

Workflow for automated quantification of cerebromicrovascular gelatinase activity.

The gelatinase enzymes, matrix metalloproteinases -2 and -9, are central mediators of blood-brain barrier disruption, actively studied in experimental models of neurological disease. Staining with in situ zymography (ISZ) allows visualization of gelatinase activity directly in brain tissue sections. However, quantifying microvascular gelatinase activity from ISZ-images is challenging and time consuming, as surrounding cell types often show significant confounding activity. We describe validation and performance of a workflow for automated image analysis of cerebromicrovascular gelatinase activity, now released for open-access use. In comparison to manual analysis, the automated workflow showed superior accuracy, was faster to execute and allows for more detailed analysis of heterogeneity in the microvasculature. We further suggest recommendations for quantifying and reporting this type of activity in experimental studies, focusing on ischemic stroke.

Identification of candidate oncogenes in human colorectal cancers with microsatellite instability.

Microsatellite instability can be found in approximately 15% of all colorectal cancers. To detect new oncogenes we sequenced the exomes of 25 colorectal tumors and respective healthy colon tissue. Potential mutation hot spots were confirmed in 15 genes; ADAR, DCAF12L2, GLT1D1, ITGA7, MAP1B, MRGPRX4, PSRC1, RANBP2, RPS6KL1, SNCAIP, TCEAL6, TUBB6, WBP5, VEGFB, and ZBTB2; these were validated in 86 tumors with microsatellite instability. ZBTB2, RANBP2, and PSRC1 also were found to contain hot spot mutations in the validation set. The form of ZBTB2 associated with colorectal cancer increased cell proliferation. The mutation hot spots might be used to develop personalized tumor profiling and therapy.

A tissue graft model of DNA damage response in the normal and malignant human prostate.

PURPOSE: DNA damage responses are relevant to prostate cancer initiation, progression and treatment. Few models of the normal and malignant human prostate that maintain stromal-epithelial interactions in vivo exist in which to study DNA damage responses. We evaluated the feasibility of maintaining tissue slice grafts at subcutaneous vs subrenal capsular sites in RAG2(-/-)γC(-/-) mice to study the DNA damage responses of normal and malignant glands. MATERIALS AND METHODS: We compared the take rate and histology of tissue slice grafts from fresh, precision cut surgical specimens that were maintained for 1 to 4 weeks in subcutaneous vs subrenal capsular sites. Induction of γH2AX, p53, ATM and apoptosis was evaluated as a measure of the DNA damage response after irradiation. RESULTS: The take rate of subcutaneous tissue slice grafts was higher than typically reported but lower than at the subrenal capsular site. Subcutaneous tissue slice grafts frequently showed basal cell hyperplasia, squamous metaplasia and cystic atrophy, and cancer did not survive. In contrast, normal and malignant histology was well maintained in subrenal capsular tissue slice grafts. Regardless of implantation site the induction of γH2AX and ATM occurred in tissue slice graft epithelium 1 hour after irradiation and decreased to basal level by 24 hours, indicating DNA damage recognition and repair. As observed previously in prostatic ex vivo models, p53 was not activated. Notably, tumor but not normal cells responded to irradiation by undergoing apoptosis. CONCLUSIONS: To our knowledge this is the first study of DNA damage responses in a patient derived prostate tissue graft model. The subrenal capsular site of RAG2(-/-)γC(-/-) mice optimally maintains normal and malignant histology and function, permitting novel studies of DNA damage responses in a physiological context.

Use of IgE and IgG4 epitope binding to predict the outcome of oral immunotherapy in cow's milk allergy.

BACKGROUND: Oral immunotherapy (OIT) with cow's milk (CM) has been reported to induce a number of specific antibody responses, but these remain to be fully characterized. Our objective was to explore whether IgE and IgG4 epitope binding profiles could predict the risk of side effects during CM OIT. METHODS: The study population consisted of 32 children (6-17 yr of age) with CM allergy: 26 children who successfully completed OIT and six children who discontinued therapy due to adverse reactions. We investigated sera drawn before and after OIT. We analyzed specific IgE and IgG4 binding to CM protein-derived peptides with a microarray-based immunoassay. Antibody binding affinity was analyzed with a competition assay where CM proteins in solution competed with peptides printed on the microarray. RESULTS: IgE binding to CM peptides decreased and IgG4 binding increased following the OIT in children who attained desensitization. Compared with children who successfully completed OIT, those who discontinued OIT due to adverse reactions developed increased quantities and affinity of epitope-specific IgE antibodies and a broader diversity of IgE and IgG4 binding, but less overlap in IgE and IgG4 binding to CM peptides. CONCLUSIONS: Detailed analysis of IgE and IgG4 binding to CM peptides may help in predicting whether CM OIT will be tolerated successfully. It may thus improve the safety of the therapy.

Quantitative proteomics and dynamic imaging of the nucleolus reveal distinct responses to UV and ionizing radiation.

The nucleolus is a nuclear organelle that coordinates rRNA transcription and ribosome subunit biogenesis. Recent proteomic analyses have shown that the nucleolus contains proteins involved in cell cycle control, DNA processing and DNA damage response and repair, in addition to the many proteins connected with ribosome subunit production. Here we study the dynamics of nucleolar protein responses in cells exposed to stress and DNA damage caused by ionizing and ultraviolet (UV) radiation in diploid human fibroblasts. We show using a combination of imaging and quantitative proteomics methods that nucleolar substructure and the nucleolar proteome undergo selective reorganization in response to UV damage. The proteomic responses to UV include alterations of functional protein complexes such as the SSU processome and exosome, and paraspeckle proteins, involving both decreases and increases in steady state protein ratios, respectively. Several nonhomologous end-joining proteins (NHEJ), such as Ku70/80, display similar fast responses to UV. In contrast, nucleolar proteomic responses to IR are both temporally and spatially distinct from those caused by UV, and more limited in terms of magnitude. With the exception of the NHEJ and paraspeckle proteins, where IR induces rapid and transient changes within 15 min of the damage, IR does not alter the ratios of most other functional nucleolar protein complexes. The rapid transient decrease of NHEJ proteins in the nucleolus indicates that it may reflect a response to DNA damage. Our results underline that the nucleolus is a specific stress response organelle that responds to different damage and stress agents in a unique, damage-specific manner.

H&E image analysis pipeline for quantifying morphological features.

Detecting cell types from histopathological images is essential for various digital pathology applications. However, large number of cells in whole-slide images (WSIs) necessitates automated analysis pipelines for efficient cell type detection. Herein, we present hematoxylin and eosin (H&E) Image Processing pipeline (HEIP) for automatied analysis of scanned H&E-stained slides. HEIP is a flexible and modular open-source software that performs preprocessing, instance segmentation, and nuclei feature extraction. To evaluate the performance of HEIP, we applied it to extract cell types from ovarian high-grade serous carcinoma (HGSC) patient WSIs. HEIP showed high precision in instance segmentation, particularly for neoplastic and epithelial cells. We also show that there is a significant correlation between genomic ploidy values and morphological features, such as major axis of the nucleus.

Contrasting DNA damage checkpoint responses in epithelium of the human seminal vesicle and prostate.

BACKGROUND: Prostate and seminal vesicle are two similar hormone responsive human organs that differ dramatically in their cancer incidence. DNA damage response (DDR) is required for maintenance of genomic integrity. METHODS: In this study we investigated the DDR and cell cycle checkpoint activation of these organs using orthotopic cultures of human surgery-derived tissues and primary cultures of isolated prostate and seminal vesicle cells. RESULTS: We find that the activation of ATM signaling pathway by ionizing radiation (IR) was comparable in both tissues. Previously, we have shown that the prostate secretory cells express low levels of histone variant H2AX and phosphorylated H2AX (γH2AX) after IR. Here we demonstrate that H2AX levels are low also in the secretory seminal vesicle cells suggesting that this is a common phenotype of postmitotic cells. We consequently established primary epithelial cell cultures from both organs to compare their DDR. Interestingly, contrary to human prostate epithelial cells (HPEC), primary seminal vesicle epithelial cells (HSVEC) displayed effective cell cycle checkpoints after IR and expressed higher levels of Wee1A checkpoint kinase. Furthermore, HSVEC but not HPEC cells were able to activate p53 and to induce p21 cell cycle inhibitor. DISCUSSION: Our results show that during replication, the checkpoint enforcement is more proficient in the seminal vesicle than in the prostate epithelium cells. This indicates a more stringent enforcement of DDR in replicating seminal vesicle epithelial cells, and suggests that epithelial regeneration combined with sub-optimal checkpoint responses may contribute to high frequency of genetic lesions in the prostate epithelium.

Cerebral mast cells mediate blood-brain barrier disruption in acute experimental ischemic stroke through perivascular gelatinase activation.

BACKGROUND AND PURPOSE: Perivascularly positioned cerebral mast cells (MC) have been shown to participate in acute blood-brain barrier disruption and expansive brain edema following experimental transient cerebral ischemia. However, the underlying molecular mechanisms remain unknown. Because proteolytic gelatinase enzymes, matrix metalloproteinases (MMP)-2 and MMP-9, are thought to have a central role in compromising the integrity of the blood-brain barrier following ischemia, we examined whether cerebral MCs influence gelatinase activity in ischemic cerebral microvasculature. METHODS: Rats underwent 60 minutes of middle cerebral artery occlusion followed by 3-hour reperfusion, and were treated with a MC-stabilizing (cromoglycate), or MC-degranulating (compound 48/80) agent, or vehicle. Genetically manipulated, MC-deficient WsRc(Ws/Ws) rats and their wild-type littermates (WT) underwent the same procedures. Cerebral edema and extravasation of Evans blue albumin were measured. Gelatinase activity was visualized by in situ zymography and was quantified with computerized high-throughput image and data analysis. RESULTS: Activated MCs showed secretion of gelatinase-positive granules. Genetic MC deficiency decreased global gelatinase-active area (-69%, compared with WT; P<0.001) and the mean gelatinase activity of the ischemic microvasculature (-57% compared with WT; P=0.002). MC stabilization with cromoglycate decreased the percentage of microvessels with high gelatinase activity (-36% compared with saline; P<0.05). Compound 48/80 showed increased area of in situ zymography activity in the ischemic lesion (+55% compared with saline; P<0.001). Microvascular gelatinase activity correlated with brain swelling (r=0.84; P<0.001; and r=0.61; P=0.02). CONCLUSIONS: Our data demonstrate that cerebral MCs participate in regulation of acute microvascular gelatinase activation and consequent blood-brain barrier disruption following transient cerebral ischemia.

Fibroblast nemosis induces angiogenic responses of endothelial cells.

Increasing evidence points to a central link between inflammation and activation of the stroma, especially of fibroblasts therein. However, the mechanisms leading to such activation mostly remain undescribed. We have previously characterized a novel type of fibroblast activation (nemosis) where clustered fibroblasts upregulated the production of cyclooxygenase-2, secretion of prostaglandins, proteinases, chemotactic cytokines, and hepatocyte growth factor (HGF), and displayed activated nuclear factor-kappaB. Now we show that nemosis drives angiogenic responses of endothelial cells. In addition to HGF, nemotic fibroblasts secreted vascular endothelial growth factor (VEGF), and conditioned medium from spheroids promoted sprouting and networking of human umbilical venous endothelial cells (HUVEC). The response was partly inhibited by function-blocking antibodies against HGF and VEGF. Conditioned nemotic fibroblast medium promoted closure of HUVEC and human dermal microvascular endothelial cell monolayer wounds, by increasing the motility of the endothelial cells. Wound closure in HUVEC cells was partly inhibited by the antibodies against HGF. The stromal microenvironment regulates wound healing responses and often promotes tumorigenesis. Nemosis offers clues to the activation process of stromal fibroblasts and provides a model to study the part they play in angiogenesis-related conditions, as well as possibilities for therapeutical approaches desiring angiogenesis in tissue.

Early recovery from cow's milk allergy is associated with decreasing IgE and increasing IgG4 binding to cow's milk epitopes.

BACKGROUND: The dynamics and balance of allergen-specific IgE, IgG4, and IgA binding might contribute to the development of tolerance in patients with cow's milk allergy (CMA). Profiling of antibody binding to cow's milk (CM) protein epitopes might help in predicting the natural history of allergy. OBJECTIVE: We sought to investigate differences in IgE, IgG4, and IgA binding to CM epitopes over time between patients with early recovery or with persisting CMA. METHODS: We studied serum samples at the time of diagnosis (mean age, 7 months), 1 year later, and at follow-up (mean age, 8.6 years) from 11 patients with persisting IgE-mediated CMA at age 8 to 9 years and 12 patients who recovered by age 3 years. We measured the binding of IgE, IgG4, and IgA antibodies to sequential epitopes derived from 5 major CM proteins with a peptide microarray-based immunoassay. We analyzed the data with a novel image-processing method together with machine learning prediction. RESULTS: IgE epitope-binding patterns were stable over time in patients with persisting CMA, whereas binding decreased in patients who recovered early. Binding patterns of IgE and IgG4 overlapped. Among patients who recovered early, the signal of IgG4 binding increased and that of IgE decreased over time. IgE and IgG4 binding to a panel of alpha(s1)-, alpha(s2)-, beta-, and kappa-casein regions predicted outcome with significant accuracy. CONCLUSIONS: Attaining tolerance to CM is associated with decreased epitope binding by IgE and a concurrent increase in corresponding epitope binding by IgG4.

Electrically Induced Blink for the Prevention of Ocular Symptoms and Blurred Vision in Patients With Acute Facial Nerve Palsy.

Objectives: Facial nerve palsy causes blurred vision and ocular discomfort due to deficits in blinking and eye closure. The objective of this study was to determine whether eye-blinks could be elicited by electrical stimulation and whether electrically induced blink would have an effect on the visual acuity and ocular symptoms in patients with acute facial nerve palsy. Methods: The zygomatic branch of the facial nerve of fifteen participants with acute facial nerve palsy was electrically stimulated in order to elicit a blink. In successful cases, the participant proceeded with a two-hour TV watching session in which an electrically induced blink was delivered every 5 seconds. The control condition consisted of an otherwise similar TV watching session without electrically induced blinking. Subjective ocular symptoms were evaluated with a Dry Eye Questionnaire and visual acuity was assessed with a Logarithm of the Minimum Angle of Resolution (LogMAR) chart before and after both sessions. Results: The stimulation produced a blink in 8 participants (53%). The visual acuity in the affected eye decreased during the control session, whereas no significant change occurred during the stimulation session. The ocular symptoms were significantly reduced during the stimulation session. Conclusions: Electrically elicited blink is a promising method for reducing the eye symptoms in individuals with acute facial nerve palsy.

Three-Dimensional Printing of the Nasal Cavities for Clinical Experiments.

3D printing has produced many beneficial applications for surgery. The technique´s applicability in replicating nasal cavity anatomy for clinical use has not been studied. Our aim was to determine whether 3D printing could realistically replicate the nasal cavities and the airflow passing through them from a clinical point of view. We included Cone Beam Computed Tomography (CBCT) scans of five patients with symptoms of chronic nasal congestion. These CBCT scans were used to print plastic 3D prints of the nasal cavities, which were also CBCT scanned and the measurements were compared. The results in vivo were higher than the results in vitro in maxillary sinus volumes with a ratio of 1.05 ± 0.01 (mean ± SD) and in the nasal cavities with a ratio of 1.20 ± 0.1 (mean ± SD). Linear measurements in vitro were very close to those in vivo. Rhinomanometric results showed some differences, but rhinomanometric graphs in vitro were close to the graphs in vivo. 3D printing proved to be a suitable and fast method for replicating nasal cavity structures and for the experimental testing of nasal function. It can be used as a complementary examination tool for rhinomanometry.

Effect of pulse waveforms on movement amplitudes and perceived discomfort in electric muscle stimulation in unresolved facial nerve palsy.

Studies on the effects of the pulse waveform used in electrical muscle stimulation on the activations and perceived discomfort of the waveform have been mainly executed on limb muscles with variable results, however, knowledge of these effects on facial muscles is currently lacking. We studied two waveforms, square wave and sinusoidal wavelet, for the activation of the frontalis muscle in 9 individuals with unresolved facial nerve palsy. Both waveforms produced a movement that was greater in amplitude compared with the maximal voluntary movement of the affected side in 8 participants and at least as great as the healthy side's maximal voluntary movement in 4 participants. Both waveforms were equally successful in producing movements, and there was no significant difference in perceived discomfort ratings between the two waveforms. These findings will be useful for the future development of neuroprosthetic applications for reanimating facial muscles using electrical stimulation. Trial registration: ClinicalTrials.gov NCT03496025, registration date March 19, 2018.