Different Stages Of Differentiation Research Articles

Lipidomics Reveals Cell Specific Changes During Pluripotent Differentiation to Neural and Mesodermal Lineages.

Due to their self-renewal and differentiation capabilities, pluripotent stem cells hold immense potential for advancing our understanding of human disease and developing cell-based or pharmacological interventions. Realizing this potential, however, requires a thorough understanding of the basal cellular mechanisms which occur during differentiation. Lipids are critical molecules that define the morphological, biochemical, and functional role of cells. This, combined with emerging evidence linking lipids to neurodegeneration, cardiovascular health, and other diseases, makes lipids a critical class of analytes to assess normal and abnormal cellular processes. While previous work has examined the lipid composition of stem cells, uncertainties remain about which changes are conserved and which are unique across distinct cell types. In this study, we investigated lipid alterations of induced pluripotent stem cells (iPSCs) at critical stages of differentiation toward neural or mesodermal fates. Lipdiomic analyses of distinct differentiation stages were completed using a platform coupling liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) separations. Results illustrated a shared triacylglyceride and free fatty acid accumulation in early iPSCs that were utilized at different stages of differentiation. Unique fluctuations through differentiation were also observed for certain phospholipid classes, sphingomyelins and ceramides. These insights into lipid fluctuations across iPSC differentiation enhance our fundamental understanding of lipid metabolism within pluripotent stem cells and during differentiation, while also paving the way for a more precise and effective application of pluripotent stem cells in human disease interventions.

Development of patient-derived lymphomoids with preserved tumor architecture for lymphoma therapy screening

The efficacy of anti-cancer therapies depends on the genomic composition of the tumor, its microenvironment, spatial organization, and intra-tumor heterogeneity. B-cell lymphomas are a heterogeneous group of tumors emerging from B-cells at different stages of differentiation and exhibiting tumor-specific interactions with the tumor microenvironment. Thus, the effect of drug treatments can be influenced by the tumor composition and functional interactions among immune cells. Here, we develop a platform to maintain small fragments of human lymphoma tissue in culture for several days, and use them to test response to small molecules. We collect 27 patient samples representative of different lymphoma subtypes, and establish ex vivo tissue fragments that retain histological, cellular, and molecular characteristics of the original tissue, here referred to as lymphomoids. Using lymphomoids, we test sensitivity to several clinically approved drugs in parallel and examine tissue remodeling upon treatment. Moreover, when this information is available, we show that the effect of the inhibitors observed in lymphomoids is consistent with the patients’ response in the clinic. Thus, lymphomoids represent an innovative ex vivo model to assess the effect of anti-cancer therapies while preserving the tissue structure and its components.

Parallelisms in the morphology and evolutionary transformations of two bones of the visceral skeleton in fossil and recent freshwater sculpins of the genus Triglopsis (Pisces: Cottidae)

The article considers the morphogenesis of two visceral skeleton bones, which are most important for identification, in five freshwater forms of the genus Triglopsis Girard, 1851. These forms evolved as a result of colonization of fresh waters by marine fishes in different geological periods and continents. On American continent, two fossil species, Triglopsis idahoensis (Smith, 1975) and T. antiquus (Smith, 1975), from the Pliocene Lake Idaho and one recent species T. thompsonii Girard, 1851 from Lake Michigan were studied. On European continent, two freshwater populations of one species T. quadricornis (Linnaeus, 1758) from Lakes Ladoga and Onega were investigated. Comparative analysis of the external features of the preopercular and dentary bones showed that all five studied forms have common characters inherent in the genus Triglopsis. The differences are in the size, shape and orientation of the spines; and hollows of the preopercular-mandibular sensory canal. The fossil species T. idahoensis and T. antiquus have wide, slightly curved preopercle with spines of similar length. Significant differences are found in the morphology of the sensory canal. The most primitive state of this canal is observed in T. antiquus. It is characterized by small size of hollows and wide bone bridges between them. Evolutionary transformations in morphology of the canal in fossil and recent species go in the direction of increasing passage of the canal in the bones. In recent forms, passage of the sensory canal occupies almost the entire width of the bone, which is significantly greater than in fossil species. Geographically remote and isolated fossil and recent forms of the genus Triglopsis, each with its own evolutionary fate, have a single trend of evolutionary transformations of the studied bones. Despite the fact that the lake forms were at different stages of differentiation, evolutionary transformations of the morphology of the studied bones proceed in parallel and in the same direction.

The role of polyreactive memory B cells in systemic lupus erythematosus.

In systemic lupus erythematosus (SLE), the production of autoantibodies is a crucial characteristic, and B cells play a significant role in its pathogenesis. B cells are the immune cells most associated with the genetic predispositions of SLE, and recent clinical studies showing that anti-CD19 CAR-T cell therapy induces drug-free remission have underscored the importance of B cells in SLE. Meanwhile, various B cell subsets exist across different stages of differentiation, from naive B cells to plasma-cells, and identifying the important subpopulations within SLE remains a critical future challenge. Years of B cell repertoire analyses have revealed the importance of polyreactive B cell receptors (BCRs) and autoantibodies that react to a various self-antigens and microbial antigens. Particularly, memory B cells with polyreactive BCRs, which play a crucial role in biological defense during the fetal stage, are characteristically differentiated in SLE. Type I interferon-mediated expression of CXCL13 and IL21 in CD4+ T cells is associated with the development of polyreactive memory B cells. The expansion of the polyreactive B cell repertoire, vital for defending against infections such as viruses, may exert an intrinsic function in SLE.

Alternative Balance between Transcriptional and Epigenetic Regulation during Developmental Proliferation of Human Cranial Neural Crest Cells.

Cranial neural crest cells are implicated in multiple transcriptional events at the different stages of differentiation during development. The alteration of some transcription factors expressed during neural crest development, like PAX7, could be implicated in the etiology of face malformation in murine models. Epigenetic regulation has been shown to be an important mechanistic actor in the control of timing and the level of gene expression at different stages of neural crest development. During this work, we investigated the interconnection between epigenetics and transcription factors across a diversity of human development cranial neural crest cells. Across a diversity of neural cells from human developing cranial tissues, in accordance with their proliferation stage, an alternative balance of regulation between transcription factors and epigenetic factors was identified.

Early markers of induced pluripotent stem cell hematopoietic development

The generation of immune cell populations from induced pluripotent stem cells (iPSCs) is a valuable model to study mechanisms that control hematopoietic development; it also is a promising approach to develop immunotherapeutic strategies to treat various diseases, including hereditary, oncological and infectious ones. To date, it has been demonstrated that iPSCs can differentiate into different immune cells, including macrophages, neutrophils, natural killer cells and T cells. However, the protocols suggested so far are experimental, and they require optimization, standardization and scaling. Solution to these tasks requires methods allowing to predict the efficacy of ongoing differentiation at early differentiation stages. Here, we evaluated whether iPSC hematopoietic/myeloid differentiation can be monitored by means of flow cytometry. Human iPSCs were differentiated into hematopoietic/myeloid cells using two protocols previously suggested for the generation of macrophages from iPSCs. The protocols differed by methods used to induce early and late stages of cell differentiation. At early differentiation stages, the protocols differed by approaches used to induce the generation of mesoderm and hemogenic endothelium, i.e., 2D differentiation in the presence of exogenous factors known to promote mesoderm and hemogenic endothelium development (“factor-dependent” protocol) or 3D differentiation in the absence of exogenous cytokines and growth factors (“spontaneous” protocol). At late differentiation stages, the protocols differed by factors added to the cultures to promote hematopoietic/myeloid specification (i.e., SCF, FGF2, IL-6, IL-3 and M-CSF or only IL-3 and M-CSF). At different stages of differentiation, the expressions of antigens known to be expressed by mesoderm, hemogenic endothelium and hematopoietic cells (i.e., CD309, CD34, CD31, CD43 and CD45) were evaluated. At early differentiation stages, the main phenotypic changes observed in cell cultures were an upregulation of the expression of CD309 (a receptor for vascular endothelial growth factor), the appearance of the expression of sialophorin CD43 and the expression of CD34 antigen. In cells cultured in 2D factor-dependent conditions, these changes appeared earlier and were more pronounced as compared with cells cultured in 3D “spontaneous” conditions. The results suggest that CD309 and/or CD43 are valuable markers for an early prediction of the effectiveness of iPSC differentiation into hematopoietic/ myeloid progeny.

Епідеміологічні дані, етіологія, патогенез, фактори ризику, клінічні прояви, сучасні методи діагностики і лікування, прогнозування перебігу Неходжкінських лімфом (огляд літератури)

Non-Hodgkin lymphoma (NHL) is a group of malignant diseases characterized by clonal proliferation of lymphoid cells corresponding to different stages of differentiation of normal B- and T- lymphocytes or natural killer (NK) cells. NHL is histopathologically and clinically diverse and divided into two groups: B-cell lymphomas and T-cell lymphomas, and subtypes: indolent (slow) and aggressive, classic and extranodal. The etiology of NHL is environmental, infectious, immunological, iatrogenic and genetic factors. The pathogenesis of NHL consists in: 1) translocations of oncogenes; 2) cytogenetic aberrations and mutations of tumor suppressor genes. Clinical manifestations of NHL: 1) lymphadenopathy; 2) symptoms of the presence of an extranodal tumor (abdominal pain; jaundice; shortness of breath and/or pleural effusion; bleeding, symptoms of gastrointestinal obstruction; symptoms associated with infiltration by lymphoma cells of the skin, thyroid gland, salivary glands, etc.; neurological symptoms of central and/or peripheral origin); 3) symptoms of bone marrow infiltration; 4) general symptoms (fever, night sweats, weight loss, fatigue, loss of appetite). Diagnosis of NHL involves: 1) auxiliary research (histological, immunohistochemical, cytogenetic and molecular, use of more specific monoclonal antibodies, immunophenotypic diagnosis, gene sequencing); 2) diagnostic tactics (estimation of stage and determination of prognostic factors according to IPI); 3) differential diagnosis (covers other causes of symptoms). The choice of treatment program for NHL depends on the type of lymphoma and the patient's condition. The main methods of treatment: wait and watch; monotherapy with alkylating drugs; RT; combined РCT; combined РCT with the use of purine analogs; therapy with monoclonal antibodies; PCT+monoclonal antibodies; HDCT+THSC. Survival prognosis for NHL depends on the origin of the tumor and its stage.

NJGCG: A node-based joint Gaussian copula graphical model for gene networks inference across multiple states

Inferring the interactions between genes is essential for understanding the mechanisms underlying biological processes. Gene networks will change along with the change of environment and state. The accumulation of gene expression data from multiple states makes it possible to estimate the gene networks in various states based on computational methods. However, most existing gene network inference methods focus on estimating a gene network from a single state, ignoring the similarities between networks in different but related states. Moreover, in addition to individual edges, similarities and differences between different networks may also be driven by hub genes. But existing network inference methods rarely consider hub genes, which affects the accuracy of network estimation. In this paper, we propose a novel node-based joint Gaussian copula graphical (NJGCG) model to infer multiple gene networks from gene expression data containing heterogeneous samples jointly. Our model can handle various gene expression data with missing values. Furthermore, a tree-structured group lasso penalty is designed to identify the common and specific hub genes in different gene networks. Simulation studies show that our proposed method outperforms other compared methods in all cases. We also apply NJGCG to infer the gene networks for different stages of differentiation in mouse embryonic stem cells and different subtypes of breast cancer, and explore changes in gene networks across different stages of differentiation or different subtypes of breast cancer. The common and specific hub genes in the estimated gene networks are closely related to stem cell differentiation processes and heterogeneity within breast cancers.

Giant mucinous liposarcoma of the abdominal cavity: A case report.

Mucinous liposarcoma myxoid liposarcoma is a malignant mucoid soft tissue tumor derived from undifferentiated stromal cells in perivascular, subbody cavity and intermuscular space, and composed of cells at different stages of differentiation from preadipocytes to mature cells. In rare cases, it may change from lipoma malignancy. The main manifestations is painless mass, relatively slow growth, the course can last decades, the prevalence of liposarcoma in the population is 14% to 18%, mainly in adults, male prevalence is higher than women, but not significant. The main good hair part is the thigh, have mucinous sex, high differentiation type, dedifferentiation type, polymorphic type. Clinical diagnosis is difficult, and there are no obvious symptoms in the early stage, so the diagnosis should be combined with B ultrasound, MRI, CT, and other auxiliary examinations. The gold standard is pathological examination. In December 2023, our department admitted a patient with a mucinous abdominal mass. The report is as follows. Does liposarcoma metastasize? Is any chemotherapy required after surgery? Will it ever relapse in the future? What is the survival period after surgery? Mucinous liposarcoma. Surgical resection of the sarcoma. The nodule sample was 33 * 28 * 13 cm, with complete capsule, gray and yellow sections, fine texture, soft, gray, red, grayish, and yellow mucoid nodules in some areas, and the maximum diameter of the nodules was 21cm. Immunohistochemistry was: CD34 (+), CDK 4 (+), CK (-), Desmin (weak +), Ki67 (index 5%), MDM 2 (-), p16 (weak +), S-100P (+), Vimentin (+), BCL-2 (+). He was also sent to the Department of Pathology of Peking Union Medical College Hospital for consultation with Professor Lu Zhaohui, whose consultation opinion was in line with myxoliposarcoma. Retroperitoneal liposarcoma is a common retroperitoneal tumor, but it is relatively rare in clinical practice; the overall morbidity is low, mainly manifested as abdominal pain and abdominal distension, abdominal distension, and a long course of disease; it is not sensitive to radiotherapy and chemotherapy, and should be closely follow up by CT examination to understand the recurrence and metastasis.

ScRNA-seq profiling of human granulocytes reveals expansion of developmentally flexible neutrophil precursors with mixed neutrophil and eosinophil properties in asthma.

Neutrophils and eosinophils share common hematopoietic precursors and usually diverge into distinct lineages with unique markers before being released from their hematopoietic site, which is the bone marrow (BM). However, previous studies identified an immature Ly6g(+) Il-5Rα(+) neutrophil population in mouse BM, expressing both neutrophil and eosinophil markers suggesting hematopoietic flexibility. Moreover, others have reported neutrophil populations expressing eosinophil-specific cell surface markers in tissues and altered disease states, confusing the field regarding eosinophil origins, function, and classification. Despite these reports, it is still unclear whether hematopoietic flexibility exists in human granulocytes. To answer this, we utilized single-cell RNA sequencing and cellular indexing of transcriptomes and epitopes by sequencing to profile human BM and circulating neutrophils and eosinophils at different stages of differentiation and determine whether neutrophil plasticity plays role in asthmatic inflammation. We show that immature metamyelocyte neutrophils in humans expand during severe asthmatic inflammation and express both neutrophil and eosinophil markers. We also show an increase in trilobed eosinophils with mixed neutrophil and eosinophil markers in allergic asthma and that interleukin-5 promotes differentiation of immature blood neutrophils into trilobed eosinophilic phenotypes, suggesting a mechanism of emergency granulopoiesis to promote myeloid inflammatory or remodeling response in patients with chronic asthma. By providing insights into unexpectedly flexible granulocyte biology and demonstrating emergency hematopoiesis in asthma, our results highlight the importance of granulocyte plasticity in eosinophil development and allergic diseases.

Current progress in chimeric antigen receptor T‐cell therapy for malignant tumors

AbstractIn the realm of malignant tumor treatment, particularly regarding hematologic malignancies, chimeric antigen receptor T‐cell (CAR‐T) immunotherapy has witnessed remarkable advancements in recent years. This approach involves genetically modifying and engineering a patient's T‐cells ex vivo to express a specific CAR, known as CAR‐T cells. When these modified cells are reintroduced into the patient, they can specifically recognize target antigens and exhibit highly efficient cytotoxicity against cells expressing these antigens, making them suitable for the treatment of malignant tumors. CD19, which is expressed on the surface of B lymphocytes at different stages of differentiation, has been identified as a suitable target for the treatment of most B‐cell lymphomas. CAR‐T cells targeting CD19 have demonstrated excellent specificity, cytotoxicity, and persistence in both in vitro and clinical trials, showing tremendous potential for application. However, identifying appropriate targets for CAR‐T therapy in solid tumors remains a challenge, leading to limited advancements in this area. This review discusses the mechanisms, applications, limitations, and prospects of CAR‐T therapy in hematologic malignancies and solid tumors, aiming to provide directions for future research in this field.

Lineage tracing reveals heterogeneity within tumor-reactive CD8 T cells in mismatch repair-proficient (MMR-p) CRC

Abstract While CRC develop in the colon and rectum, little is known about the relationship between tissue resident memory (TRM) CD8 T cells and newly recruited tumor-reactive T cells. We compared the phenotype of CD8 T cells from paired adjacent normal colon (NC) and tumor by flow cytometry and observed a higher T cell infiltration in the tumor with an enrichment in CD8 T cells. Interestingly, a subset of CD103+ CD8 T cells in NC expressed CD39, a phenotype reminiscent of tumor-reactive T cells, but those cells lacked PD-1 and Ki-67. To better understand the relationship between T cells from NC and tumor and to uncover the differentiation path of tumor-reactive CD8 T cells, we performed scRNA-seq and scTCR-seq together with CITE-seq on paired NC and tumor from five patients. We confirmed that DP CD8 T cells from NC were distinct from tumor-infiltrating DP CD8 T cells (DP CD8 TILs). In contrast, the latter represented an heterogenous population with cells at different stages of differentiation as illustrated by the detection of cells sharing the same TCRs in multiple cell clusters. To further appreciate the differentiation path of neoantigen-reactive CD8 TILs, we performed neoantigen discovery on three of the five patients. We are now evaluating whether T cell differentiation and activation are linked to functional avidity and cellular location in the tumor. This work provides essential information regarding the differentiation of tumor-reactive CD8 TILs in MMR-p CRC tumors.

Reciprocal negative feedback between Prrx1 and miR-140-3p regulates rapid chondrogenesis in the regenerating antler

During growth phase, antlers exhibit a very rapid rate of chondrogenesis. The antler is formed from its growth center reserve mesenchyme (RM) cells, which have been found to be the derivatives of paired related homeobox 1 (Prrx1)-positive periosteal cells. However, the underlying mechanism that drives rapid chondrogenesis is not known. Herein, the miRNA expression profiles and chromatin states of three tissue layers (RM, precartilage, and cartilage) at different stages of differentiation within the antler growth center were analyzed by RNA-sequencing and ATAC-sequencing. We found that miR-140-3p was the miRNA that exhibited the greatest degree of upregulation in the rapidly growing antler, increasing from the RM to the cartilage layer. We also showed that Prrx1 was a key upstream regulator of miR-140-3p, which firmly confirmed by Prrx1 CUT&Tag sequencing of RM cells. Through multiple approaches (three-dimensional chondrogenic culture and xenogeneic antler model), we demonstrated that Prrx1 and miR-140-3p functioned as reciprocal negative feedback in the antler growth center, and downregulating PRRX1/upregulating miR-140-3p promoted rapid chondrogenesis of RM cells and xenogeneic antler. Thus, we conclude that the reciprocal negative feedback between Prrx1 and miR-140-3p is essential for balancing mesenchymal proliferation and chondrogenic differentiation in the regenerating antler. We further propose that the mechanism underlying chondrogenesis in the regenerating antler would provide a reference for helping understand the regulation of human cartilage regeneration and repair.

Understanding fish B cell responses to combat infectious diseases

Teleost fish possess all the necessary elements to mount an adaptive immune response, yet, the many physiological and structural differences between the mammalian and the teleost adaptive immune system, anticipate significant changes regarding how this response is coordinated and executed. As a result, the adaptive response in fish is often slower and weaker than that of mammals. B cells are key players in adaptive immune responses through the production of antibodies. Nonetheless, recent studies performed in mammals and other species including fish point to many additional functions of B cells within both the adaptive and the innate immune system, in many occasions taking part in the crosstalk between these two arms of the immune response. Furthermore, it should be taken into consideration that fish B cells share many functional and phenotypical features with mammalian innate B cell populations, also greatly conditioning their response to pathogens. Our knowledge regarding B cell function in fish has increased greatly in the past years, studies that have allowed us for example to identify different subsets of B cells, detect specific antibody-secreting cells or even establish the transcriptomic profile and the B cell receptor sequence of single cells in different stages of differentiation. In the current work, we will summarize what is currently known regarding fish B cells, knowledge that is essential for the future design of novel strategies to combat infectious diseases.

Brain neurotrophic factor BDNF: new data, functions and questions

The brain-derived neurotrophic factor (BDNF) is a key modulator of neurogenesis, synaptogenesis, neuroregeneration, and cell differentiation in the nervous system. Impaired BDNF functioning is a characteristic of various neurological diseases, such as Alzheimer’s disease, multiple sclerosis, and depressive disorders. There is recent evidence that patients with COVID-19 have reduced BDNF levels in the blood plasma. Furthermore, exogenous BDNF and its mimetics have demonstrated therapeutic potential.
 In this review, we systematized data of the BDNF gene structure, epigenetic and microRNA-mediated regulation of its expression, transcriptional variants of BDNF, and the effects of BDNF on neuronal and oligodendroglial differentiation. Further, we point out the gaps in the current knowledge about BDNF and propose experiments that can expand such knowledge and the range of possibilities for using BDNF in biomedicine. These include determining the expression pattern of all BDNF gene transcripts at different stages of differentiation and in different cell subpopulations and studying the role of receptor-independent BDNF signaling, circadian fluctuations in BDNF levels, and their role in physiological and pathophysiological conditions. Finally, for translational medicine, evaluating the effect of BDNF mimetics (including those immobilized on three-dimensional scaffolds for tissue engineering) on neuronal and oligodendroglial differentiation of pluripotent and polypotent cells and identifying molecular regulators of BDNF transcription, including small molecules and microRNAs capable of regulating BDNF gene expression, are crucial.

Noninvasive Assessment of hiPSC Differentiation toward Cardiomyocytes Using Pretrained Convolutional Neural Networks and the Channel Pruning Algorithm.

Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hiPSC-CMs) offer versatile applications in tissue engineering and drug screening. To facilitate the monitoring of hiPSC cardiac differentiation, a noninvasive approach using convolutional neural networks (CNNs) was explored. HiPSCs were differentiated into cardiomyocytes and analyzed using the quantitative real-time polymerase chain reaction (qRT-PCR). The bright-field images of the cells at different time points were captured to create the dataset. Six pretrained models (AlexNet, GoogleNet, ResNet 18, ResNet 50, DenseNet 121, VGG 19-BN) were employed to identify different stages in differentiation. VGG 19-BN outperformed the other five CNNs and exhibited remarkable performance with 99.2% accuracy, recall, precision, and F1 score and 99.8% specificity. The pruning process was then applied to the optimal model, resulting in a significant reduction of model parameters while maintaining high accuracy. Finally, an automation application using the pruned VGG 19-BN model was developed, facilitating users in assessing the cell status during the myocardial differentiation of hiPSCs.

Abstract 3877: Multi-modal analysis of paracrine signaling in group 3/4 medulloblastoma

Abstract Medulloblastoma (MB) is the most common primary brain malignancy in kids, with the group 3 and 4 subtypes (G3/4) being the most aggressive. Recent single-cell genomics studies have identified the G3/4 MB cell of origin and point to disrupted stem-cell differentiation as a key factor in MB pathogenesis. However, surprisingly little is known about the contribution of tumor-supportive paracrine signaling to the ontogeny of this disease. The spatial organization of MB cellular hierarchies is not completely understood. We profiled N=24 G3/4 MBs from UCSF patients via single-nucleus RNA sequencing (snRNA-seq). Of these cases, N=10 were profiled via single-cell assay for transposase-accessible chromatin by sequencing (scATAC-seq). To capture the spatial context, we profiled an additional 20 samples via spatial transcriptomics using the Visium and Xenium platforms. We found that the standard Xenium brain capture set was inadequate, and we developed a highly specific capture set for G3/4 MBs. In particular, our panel resolves cell-type differences in the stage of MB lineage commitment, from rhombic-lip progenitors to more differentiated unipolar brush-like cells. Altogether, over 110,000 nuclear-sequencing libraries and over 1,898,000 spatially-resolved single-cell libraries were generated. We inferred cell-cell communication signals from our snRNA-seq data by identifying co-expressed receptors and their cognate ligands. We then performed an integrated analysis of our snRNA-seq and scATAC-seq data to infer the cis-regulatory enhancers of those signaling genes, as well as the transcription factors that bind them. We employed our spatial transcriptomics data to confirm paracrine signaling networks inferred from nuclear-sequencing data. We found that distinct MB cell types corresponding to different stages of differentiation occupied specific spatial domains. The results of our ongoing analysis of this spatially-resolved single-cell atlas will be presented. This study paves the way for innovative therapeutic strategies targeting paracrine signaling in G3/4 MB. Citation Format: Bohyeon Yu, Jangham Jung, Aaron Diaz. Multi-modal analysis of paracrine signaling in group 3/4 medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3877.

Screening and identification of lncRNAs in preadipocyte differentiation in sheep

Studies of preadipocyte differentiation and fat deposition in sheep have mainly focused on functional genes, and with no emphasis placed on the role that long non-coding RNAs (lncRNAs) may have on the activity of those genes. Here, the expression profile of lncRNAs in ovine preadipocyte differentiation was investigated and the differentially expressed lncRNAs were screened on day 0 (D0), day 2(D2) and day 8(D8) of ovine preadipocyte differentiation, with their target genes being predicted. The competing endogenous RNA (ceRNA) regulatory network was constructed by GO and KEGG enrichment analysis for functional annotation, and some differentially expressed lncRNAs were randomly selected to verify the RNA-Seq results by RT-qPCR. In the study, a total of 2517 novel lncRNAs and 3943 known lncRNAs were identified from ovine preadipocytes at the three stages of differentiation, with the highest proportion being intergenic lncRNAs. A total of 3455 lncRNAs were expressed at all three stages of preadipocyte differentiation, while 214, 226 and 228 lncRNAs were uniquely expressed at day 0, day 2 and day 8, respectively. By comparing the expression of the lncRNAs between the three stages of differentiation stages, a total of 405, 272 and 359 differentially expressed lncRNAs were found in D0-vs-D2, D0-vs-D8, and D2-vs-D8, respectively. Functional analysis revealed that the differentially expressed lncRNAs were enriched in signaling pathways related to ovine preadipocyte differentiation, such as mitogen-activated protein kinase (MAPK) pathway, the phosphoinositide 3-kinase protein kinase B (PI3K-Akt) pathway, and the transforming growth factor beta (TGF-β) pathway. In summary, lncRNAs from preadipocytes at different stages of differentiation in sheep were identified and screened using RNA-Seq technology, and the regulatory mechanisms of lncRNAs in preadipocyte differentiation and lipid deposition were explored. This study provides a theoretical reference for revealing the roles of lncRNAs in ovine preadipocyte differentiation and also offers a theoretical basis for further understanding the regulatory mechanisms of ovine preadipocyte differentiation.

Субпопуляционный состав T-хелперов у больных острыми лейкозами после трансплантации аллогенных гемопоэтических стволовых клеток

Aim. To identify the characteristics of T-helper subpopulations in healthy donors and to compare them with those reported in acute leukemia patients 6 months after allogeneic hematopoietic stem cell transplantation (allo-HSCT).
 Materials & Methods. The study enrolled 41 blood donors and 49 patients after-HSCT. The median age of donors was 36 years (range 20–60 years), 29 of them were men and 12 were women. The median age of patients was 37 years (range 19–62 years), 18 of them were men and 31 were women. Acute myeloid leukemia was diagnosed in 27 (55 %) patients and acute lymphoblastic leukemia/lymphoma in 22 (45 %) patients. Myeloablative conditioning was administered to 4 (8 %) patients and reduced intensity conditioning to 45 (92 %) patients. T-helper subpopulations were studied in the blood of healthy donors vs. acute leukemia patients after allo-HSCT. The flow cytometry analysis was conducted to simultaneously assess the expression of markers CD3, CD4, CD8, CD25, CD45RA, CD197, CD28, CCR4, CCR6, CCR10, CXCR3, and CXCR5 in T-cells.
 Results. The study demonstrated that the count of T-helpers at different stages of differentiation (regulatory, naive T-cells, memory cells, and effector cells) comprehensively distinguishes healthy donors from patients. Moreover, the functional structure of each of these populations differ in donors vs. patients even on Month +6 after allo-HSCT. Donors appeared to have more polarized cells among the central memory T-helpers. The proportion of T-helpers type 1 among the effector cells was higher is patients.
 Conclusion. The results of the study indicate that the Т-cell parameter set can be analyzed to assess immunity and to describe its disorders in different pathologies or after drug chemotherapy.

Microstructural analysis of meat and internal organs of broiler chickens using a probiotic biological product

Probiotic preparation containing bacteria of the genus Bacillus subtilis and Bacillus licheniformis used for feeding broiler chickens to improve feed digestion, nutrient absorption, increase immune status and productivity, and for the prevention and treatment of various poultry diseases. The purpose of the study is to conduct histological tests of broiler chicken slaughter products when they were administered a probiotic biologic medical product in doses of: 0.5 g, 2.0, and 4.0 g per 10 dm3 of water. The material was examined by the histological method. It was found that the muscle fibres in the pectoralis major are of the same type, evenly directed, the cytoplasm of muscle fibres is moderately eosinophilic, uniformly light pink, and minor layers of adipose tissue are found between the bundles of muscle fibres. The morphological architectonics of the heart muscle are preserved, cardiomyocytes are homogeneous and have a clear orientation. The microstructure of the liver of broiler chickens is unchanged: hepatocytes are collected in the same type of groups; the central veins are desolate; the cytoplasm of these cells is homogeneous, clear, and pink; the nuclei are weakly basophilic. In the spleen, the follicular structure is formed, leukocytes are diffusely placed at different stages of differentiation; vessels in significant numbers, thickened, of different calibre. The cuticle of the muscular part of the stomach contains the epithelial layer, the volume part of the connective tissue base layer is revealed; muscle fibres are located under the mesenchymal base of the cuticle. Lungs by morphological structure have bronchial tubes throughout the structure, which contain blood cells. According to the results of the conducted studies, a beneficial effect of a probiotic biological product at a dose of 4.0 g/10 dm3 of water on the morphology of the pectoralis major and internal organs of broiler chickens was established. Therefore, a probiotic at a dose of 4.0 g/10 dm3 of water during the drinking of broiler chickens can be recommended to increase productivity and produce safe slaughter products. The practical significance of the results obtained is to determine the features of the effect of feeding poultry with different doses of probiotics on the microstructure of its slaughter products, which is important for obtaining the best effect from its use