Proliferation Of Progenitor Cells Research Articles

Not just for lymphoid cells: the role of the noncanonical NF-κB signaling pathway in early and late myelopoiesis with a focus on hypereosinophilic disorders.

The noncanonical NF-κB pathway is involved in lymphoid organ development, B-cell maturation, and cytokine production. However, new research has demonstrated that this pathway is also key for the orderly and sequential maturation of myeloid cells, including neutrophils and eosinophils. When this pathway is disrupted or constitutively activated, aberrations in hematopoietic stem and progenitor cell survival and proliferation, as well as subsequent granulopoiesis and eosinophilopoiesis, are affected. Disturbance of such a coordinated and delicate process can manifest in devastating clinical disease, including acute and chronic myeloid leukemias, preleukemic processes such as myelodysplastic syndrome, or hyperinflammatory conditions like hypereosinophilic syndrome. In this review, we discuss the molecular machinery within the noncanonical NF-κB pathway, crosstalk with the canonical NF-κB pathway, murine models of noncanonical signaling, and how aberrations in this pathway manifest in leukemic or hyperinflammatory disease with a focus on hypereosinophilic syndrome. Potential and promising drug therapies will also be discussed, emphasizing the noncanonical NF-κB pathway as a potential target for improved treatment for patients with leukemia or idiopathic hypereosinophilic syndrome. The hope is that review of such mechanisms and treatments may eventually result in findings that aid physicians in rapidly diagnosing and more accurately classifying patients with such complex and overlapping hematopoietic diseases.

HDAC1/2 and HDAC3 play distinct roles in controlling adult Meibomian gland homeostasis

PurposeTo investigate the roles of HDAC1/2 and HDAC3 in adult Meibomian gland (MG) homeostasis. MethodsHDAC1/2 or HDAC3 were inducibly deleted in MG epithelial cells of adult mice. The morphology of MG was examined. Proliferation, apoptosis, and expression of MG acinus and duct marker genes, meibocyte differentiation genes, and HDAC target genes, were analyzed via immunofluorescence, TUNEL assay, and RNA in situ hybridization. ResultsCo-deletion of HDAC1/2 in MG epithelium caused gradual loss of acini and formation of cyst-like structures in the central duct. These phenotypes required homozygous deletion of both HDAC1 and HDAC2, indicating that they function redundantly in the adult MG. Short-term deletion of HDAC1/2 in MG epithelium had little effect on meibocyte maturation but caused decreased proliferation of acinar basal cells, excessive DNA damage, ectopic apoptosis, and increased p53 acetylation and p16 expression in the MG. By contrast, HDAC3 deletion in MG epithelium caused dilation of central duct, atrophy of acini, defective meibocyte maturation, increased acinar basal cell proliferation, and ectopic apoptosis and DNA damage. Levels of p53 acetylation and p21 expression were elevated in HDAC3-deficient MGs, while the expression of the differentiation regulator PPARγ and the differentiation markers PLIN2 and FASN was downregulated. ConclusionsHDAC1 and HDAC2 function redundantly in adult Meibomian gland epithelial progenitor cells and are essential for their proliferation and survival, but not for acinar differentiation, while HDAC3 is required to limit acinar progenitor cell proliferation and permit differentiation. HDAC1/2 and HDAC3 have partially overlapping roles in maintaining survival of MG cells.

Impact of metformin on neocortical development during pregnancy: Involvement of ERK and p35/CDK5 pathways

Metformin, the most commonly prescribed drug for the treatment of diabetes, is increasingly used during pregnancy to address various disorders such as diabetes, obesity, preeclampsia, and metabolic diseases. However, its impact on neocortex development remains unclear. Here, we investigated the direct effects of metformin on neocortex development, focusing on ERK and p35/CDK5 regulation. Using a pregnant rat model, we found that metformin treatment during pregnancy induces small for gestational age (SGA) and reduces relative cortical thickness in embryos and neonates. Additionally, we discovered that metformin inhibits neural progenitor cell proliferation in the sub-ventricular zone (SVZ)/ventricular zone (VZ) of the developing neocortex, a process possibly mediated by ERK inactivation. Furthermore, metformin induces neuronal apoptosis in the SVZ/VZ area of the developing neocortex. Moreover, metformin retards neuronal migration, cortical lamination, and differentiation, potentially through p35/CDK5 inhibition in the developing neocortex. Remarkably, compensating for p35 through in utero electroporation partially rescues metformin-impaired neuronal migration and development. In summary, our study reveals that metformin disrupts neocortex development by inhibiting neuronal progenitor proliferation, neuronal migration, cortical layering, and cortical neuron maturation, likely via ERK and p35/CDK5 inhibition. Consequently, our findings advocate for caution in metformin usage during pregnancy, given its potential adverse effects on fetal brain development.

Transcription factor Olig2 is a major downstream effector of histone demethylase Phf8 during oligodendroglial development.

The plant homeodomain finger protein Phf8 is a histone demethylase implicated by mutation in mice and humans in neural crest defects and neurodevelopmental disturbances. Considering its widespread expression in cell types of the central nervous system, we set out to determine the role of Phf8 in oligodendroglial cells to clarify whether oligodendroglial defects are a possible contributing factor to Phf8-dependent neurodevelopmental disorders. Using loss- and gain-of-function approaches in oligodendroglial cell lines and primary cell cultures, we show that Phf8 promotes the proliferation of rodent oligodendrocyte progenitor cells and impairs their differentiation to oligodendrocytes. Intriguingly, Phf8 has a strong positive impact on Olig2 expression by acting on several regulatory regions of the gene and changing their histone modification profile. Taking the influence of Olig2 levels on oligodendroglial proliferation and differentiation into account, Olig2 likely acts as an important downstream effector of Phf8 in these cells. In line with such an effector function, ectopic Olig2 expression in Phf8-deficient cells rescues the proliferation defect. Additionally, generation of human oligodendrocytes from induced pluripotent stem cells did not require PHF8 in a system that relies on forced expression of Olig2 during oligodendroglial induction. We conclude that Phf8 may impact nervous system development at least in part through its action in oligodendroglial cells.

Hepatic stellate cells and their role in the formation of the progenitor cell niche

The processes of proliferation and differentiation of progenitor and stem cells in the body are ensured by a specific microenvironment, the stem cell niche. Universal components have been identified for all niches: supporting cells, extracellular matrix, and soluble biological factors. A niche is a dynamic system whose activity depends on regeneration needs.The review presents data on the structure of the hepatic stem cell niche and one of its main components – stellate cells and their role in pathology.

Harnessing developmental dynamics of spinal cord extracellular matrix improves regenerative potential of spinal cord organoids

Neonatal spinal cord tissues exhibit remarkable regenerative capabilities as compared to adult spinal cord tissues after injury, but the role of extracellular matrix (ECM) in this process has remained elusive. Here, we found that early developmental spinal cord had higher levels of ECM proteins associated with neural development and axon growth, but fewer inhibitory proteoglycans, compared to those of adult spinal cord. Decellularized spinal cord ECM from neonatal (DNSCM) and adult (DASCM) rabbits preserved these differences. DNSCM promoted proliferation, migration, and neuronal differentiation of neural progenitor cells (NPCs) and facilitated axonal outgrowth and regeneration of spinal cord organoids more effectively than DASCM. Pleiotrophin (PTN) and Tenascin (TNC) in DNSCM were identified as contributors to these abilities. Furthermore, DNSCM demonstrated superior performance as a delivery vehicle for NPCs and organoids in spinal cord injury (SCI) models. This suggests that ECM cues from early development stages might significantly contribute to the prominent regeneration ability in spinal cord.

A prediction model for reactivation of Langerhans cell histiocytosis based on machine-learning algorithms.

Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasm characterized by the clonal proliferation of myeloid progenitor cells. The reactivation rate of LCH exceeds 30%. However, an effective prediction model to predict reactivation is lacking. To select potential prognostic factors of LCH and construct an easy-to-use predictive model based on machine-learning algorithms. Clinical records of LCH inpatients in the Second Xiangya Hospital of Central South University, from 2008 to 2022, were retrospectively studied. Seventy-six patients were classified into a reactivated/progressive group or a stable group. Clinical features and laboratory outcomes were compared, and machine-learning algorithms were used for building prognostic prediction models. Clinical classification (single-system LCH, multiple-system LCH, and central nervous system/lung LCH), level of anemia, bone involvement, skin involvement, and elevated monocyte count were the best performing factors and were finally chosen for the construction of the prediction models. Our results show that the above-mentioned five factors can be used together in a prediction model for the prognosis of LCH patients. The major limitations of this study include its retrospective nature and the relatively small sample size.

A primary culture method for the easy, efficient, and effective acquisition of oligodendrocyte lineage cells from neonatal rodent brains

Oligodendrocytes (OL) are myelin-forming glial cells in the central nervous system. In vitro primary OL culture models offer the benefit of a more readily controlled environment that facilitates the examination of diverse OL stages and their intricate dynamics. Although conventional methods for primary OL culture exist, their performance in terms of simplicity and efficiency can be improved. Here, we introduce a novel method for primary OL culture, namely the E3 (easy, efficient, and effective) method, which greatly improves the simplicity and efficiency of the primary OL culture procedure using neonatal rodent brains. We also provided the optimal media composition for the augmentation of oligodendrocyte progenitor cell (OPC) proliferation and more robust maturation into myelin-forming OLs. Overall, E3 offers an undemanding method for obtaining primary OLs with high yield and quality. Alongside its value as a practical tool, in vitro characteristics of the OL lineage additionally identified during the development of the E3 method have implications for advancing research on OL physiology and pathophysiology.

179 Stem Progenitor Cell Proliferation in the Brainstem After Spinal Cord Injury: A Potential Target for Therapeutic Intervention Distant From the Site of Injury

INTRODUCTION: Though there has been an increasing number of clinical trials focused on modulating stem/progenitor cell proliferation in the spinal cord after spinal cord injury (SCI), little is known about the acute response of stem/progenitor cells in supraspinal structures. We hypothesized that the signals stimulating stem/progenitor cell proliferation in the spinal cord after SCI activate similar responses in supraspinal regions because pathways injured in the spinal cord have their targets or sources in the brain. METHODS: We employed a mouse model of SCI, bromodeoxyuridine (BrdU) labeling of cells in S-phase, and co-labeling of markers of astrocytes, microglia, glial/oligodendrocyte precursor cells, and neuronal lineages to characterize the proliferative response within the brainstem of C57BL/6J mice 96 hours after a thoracic SCI. The extent of SCI and white matter (WM) spared was quantified by labeling of beta amyloid precursor protein and eriochrome cyanine R staining, respectively. RESULTS: Compared to sham-operated mice, there was a significant increase (3-fold; p < 0.01) in BrdU-labeled cells in the ventral-caudal medulla of injured mice. This response was consistent with the extent of SCI and primarily in WM tracts (57%) and the inferior olive (41%; IO). Co-labeling with cell-specific markers indicated that this response is glial (i.e., NG-2+ glial/oligodendrocyte precursor cells and GFAP+ astrocytes) with the largest increase in the number of BrdU-labeled cells occurring in the IO (6-fold increase; p < 0.01). Notably, there were no BrdU-labeled cells that co-labeled with markers of microglia or neuronal lineages. CONCLUSIONS: Our results demonstrate a stem/progenitor cell response within days of SCI that occurs distant from the injury site, notably in brainstem structures involved in motor learning and coordination. These findings highlight an acute response of glial/oligodendrocyte precursor cells in the brainstem as a potential target for future studies and therapeutic intervention after SCI.

Transcriptome-based deep learning analysis identifies drug candidates targeting protein synthesis and autophagy for the treatment of muscle wasting disorder

Sarcopenia, the progressive decline in skeletal muscle mass and function, is observed in various conditions, including cancer and aging. The complex molecular biology of sarcopenia has posed challenges for the development of FDA-approved medications, which have mainly focused on dietary supplementation. Targeting a single gene may not be sufficient to address the broad range of processes involved in muscle loss. This study analyzed the gene expression signatures associated with cancer formation and 5-FU chemotherapy-induced muscle wasting. Our findings suggest that dimenhydrinate, a combination of 8-chlorotheophylline and diphenhydramine, is a potential therapeutic for sarcopenia. In vitro experiments demonstrated that dimenhydrinate promotes muscle progenitor cell proliferation through the phosphorylation of Nrf2 by 8-chlorotheophylline and promotes myotube formation through diphenhydramine-induced autophagy. Furthermore, in various in vivo sarcopenia models, dimenhydrinate induced rapid muscle tissue regeneration. It improved muscle regeneration in animals with Duchenne muscular dystrophy (DMD) and facilitated muscle and fat recovery in animals with chemotherapy-induced sarcopenia. As an FDA-approved drug, dimenhydrinate could be applied for sarcopenia treatment after a relatively short development period, providing hope for individuals suffering from this debilitating condition.

Pharmacological p38 MAPK inhibitor SB203580 enhances AML stem cell line KG1a chemosensitivity to daunorubicin by promoting late apoptosis, cell growth arrest in S-phase, and miR-328-3p upregulation

Acute myeloid leukaemia (AML) is characterized by uncontrolled proliferation of myeloid progenitor cells and impaired maturation, leading to immature cell accumulation in the bone marrow and bloodstream, resulting in hematopoietic dysfunction. Chemoresistance, hyperactivity of survival pathways, and miRNA alteration are major factors contributing to treatment failure and poor outcomes in AML patients. This study aimed to investigate the impact of the pharmacological p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 on the chemoresistance potential of AML stem cell line KG1a to the therapeutic drug daunorubicin (DNR). KG1a and chemosensitive leukemic HL60 cells were treated with increasing concentrations of DNR. Cell Titer-Glo®, flow cytometry, phosphokinase and protein arrays, Western blot technology, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were employed for assessment of cell viability, half-maximal inhibitory concentration (IC50) determination, apoptotic status detection, cell cycle analysis, apoptosis-related protein and gene expression monitoring. Confocal microscopy was used to visualize caspase and mitochondrial permeability transition pore (mPTP) activities. Exposed at various incubation times, higher DNR IC50 values were determined for KG1a cells than for HL60 cells, confirming KG1a cell chemoresistance potential. Exposed to DNR, late apoptosis induction in KG1a cells was enhanced after SB203580 pretreatment, defined as the combination treatment. This enhancement was confirmed by increased cleavage of poly(ADP-ribose) polymerase, caspase-9, caspase-3, and augmented caspase-3/-7 and mPTP activities in KG1a cells upon combination treatment, compared to DNR. Using phosphokinase and apoptosis protein arrays, the combination treatment decreased survival Akt phosphorylation and anti-apoptotic Bcl-2 expression levels in KG1a cells while increasing the expression levels of the tumor suppressor p53 and cyclin-dependent kinase inhibitor p21, compared to DNR. Cell cycle analysis revealed KG1a cell growth arrest in G2/M-phase caused by DNR, while combined treatment led to cell growth arrest in S-phase, mainly associated with cyclin B1 expression levels. Remarkably, the enhanced KG1a cell sensitivity to DNR after SB203580 pretreatment was associated with an increased upregulation of miR-328-3p and slight downregulation of miR-26b-5p, compared to DNR effect. Altogether, these findings could contribute to the development of a new therapeutic strategy by targeting the p38 MAPK pathway to improve treatment outcomes in patients with refractory or relapsed AML.

IL-17RA Signaling in Prx1+ Mesenchymal Cells Influences Fracture Healing in Mice.

Fracture healing is a complex series of events that requires a local inflammatory reaction to initiate the reparative process. This inflammatory reaction is important for stimulating the migration and proliferation of mesenchymal progenitor cells from the periosteum and surrounding tissues to form the cartilaginous and bony calluses. The proinflammatory cytokine interleukin (IL)-17 family has gained attention for its potential regenerative effects; however, the requirement of IL-17 signaling within mesenchymal progenitor cells for normal secondary fracture healing remains unknown. The conditional knockout of IL-17 receptor a (Il17ra) in mesenchymal progenitor cells was achieved by crossing Il17raF/F mice with Prx1-cre mice to generate Prx1-cre; Il17raF/F mice. At 3 months of age, mice underwent experimental unilateral mid-diaphyseal femoral fractures and healing was assessed by micro-computed tomography (µCT) and histomorphometric analyses. The effects of IL-17RA signaling on the osteogenic differentiation of fracture-activated periosteal cells was investigated in vitro. Examination of the intact skeleton revealed that the conditional knockout of Il17ra decreased the femoral cortical porosity but did not affect any femoral trabecular microarchitectural indices. After unilateral femoral fractures, Il17ra conditional knockout impacted the cartilage and bone composition of the fracture callus that was most evident early in the healing process (day 7 and 14 post-fracture). Furthermore, the in vitro treatment of fracture-activated periosteal cells with IL-17A inhibited osteogenesis. This study suggests that IL-17RA signaling within Prx1+ mesenchymal progenitor cells can influence the early stages of endochondral ossification during fracture healing.

A role for TGFβ signaling in Gli1+ tendon and enthesis cells.

The development of musculoskeletal tissues such as tendon, enthesis, and bone relies on proliferation and differentiation of mesenchymal progenitor cells. Gli1+ cells have been described as putative stem cells in several tissues and are presumed to play critical roles in tissue formation and maintenance. For example, the enthesis, a fibrocartilage tissue that connects tendon to bone, is mineralized postnatally by a pool of Gli1+ progenitor cells. These cells are regulated by hedgehog signaling, but it is unclear if TGFβ signaling, necessary for tenogenesis, also plays a role in their behavior. To examine the role of TGFβ signaling in Gli1+ cell function, the receptor for TGFβ, TbR2, was deleted in Gli1-lineage cells in mice at P5. Decreased TGFβ signaling in these cells led to defects in tendon enthesis formation by P56, including defective bone morphometry underlying the enthesis and decreased mechanical properties. Immunohistochemical staining of these Gli1+ cells showed that loss of TGFβ signaling reduced proliferation and increased apoptosis. Invitro experiments using Gli1+ cells isolated from mouse tail tendons demonstrated that TGFβ controls cell proliferation and differentiation through canonical and non-canonical pathways and that TGFβ directly controls the tendon transcription factor scleraxis by binding to its distant enhancer. These results have implications in the development of treatments for tendon and enthesis pathologies.

Abstract 7635: Orion™: 14-plex clinical sample imaging of liver cancer modalities using one-step staining and imaging

Abstract Background To better understand the complexities of the tumor microenvironment (TME), high-resolution imaging at a sub-cellular resolution and high-plex is needed. These serve as a basis for biomarker quantification and more downstream, may provide the ability to predict patient outcome. Here, we investigate three whole slide liver sections: fetal liver, hepatocellular carcinoma (HCC), and colorectal cancer (CRC) liver metastasis. Methods 5-micron sections were cut and mounted on Superfrost Plus slides prior to de-paraffinization and antigen retrieval using the BioGenex EZ-Retriever system. Autofluorescence was quenched using UV and white light and blocked with Image-iT™ FX Signal Enhancer. Whole slides were stained with the 14-plex antibody panel, coverslip mounted with ArgoFluor™ Mounting Medium and cured overnight. Whole slides were imaged at 20X using the Orion™ spatial biology platform. Coverslips were removed in aqueous solution prior to H&E staining and scanning. Results Sample specific differences were observed, likely stemming from the different tissue sources. Data revealed a distinction between hepatocytes highlighted in the autofluorescence channel, sinusoids filled with proliferating progenitor cell and macrophages, and epithelial cells lining the border of the fetal liver forming the ductal plate surrounding the portal vein. Whereas in HCC, imaging revealed autofluorescent hepatocytes obliterating the sinusoids with some hepatocytes dividing, an extensive capillary network, and red bloods cells also highlighted in the auto fluorescent channel. T cells and macrophages showed clustering within the capillary networks and as expected, hepatocytes expressed high levels of Albumin. In the CRC liver metastasis sample, hepatocytes were shown to be surrounded by T cells, neoplastic glands (PanCK), and CD163+FOLR2+ macrophages. Furthermore, the majority of the metastatic epithelial cancer cells were observed to be proliferating. Conclusions We were able to observe precise differences in the tissue architecture of liver samples from three divergent sources. Specifically, the ability to identify distinct cell subtypes and their spatial co-localization may provide mechanistic insights into the spatial immune landscape and its role in disease progression and treatment outcome. This exemplifies the need for dissecting the spatial heterogeneity of the TME using a technology that offers a high-resolution subcellular snapshot in time; exhibiting the potential for Orion to bridge the gap from bench-to-bedside. Citation Format: Selena Larkin, Jennifer Currenti, Rhea Pai, Soumi Chatterjee, Archita Mishra, Jacob George, Brady Gardner, Ankur Sharma. Orion™: 14-plex clinical sample imaging of liver cancer modalities using one-step staining and imaging [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 7635.

Abstract 2054: A sensitive and specific human primary stem cell-based in vitro assay for predicting the gastrointestinal toxicity risk of therapeutic agents

Abstract Gastrointestinal (GI) toxicities are the most common drug-induced adverse events in human clinical trials. Drugs that cause GI toxicities often affect the proliferative stem and progenitor cell populations responsible for maintaining the cellular composition, self-renewing capacity, and barrier function of the intestinal epithelium. This disruption leads to impaired GI barrier integrity, culminating in a broad range of clinical symptoms, including diarrhea, inflammation, and increased risk of infection. The impact of GI toxicity is substantial and can cause dose-limiting clinical side-effects that may affect patient compliance and dosing adherence. Common nonclinical animal models, including rats, mice and dogs are often poor predictors of human GI toxicity and safety outcomes. Furthermore, in vivo animal testing poses limited screening throughput, which is particularly important in fields such as oncology, where matrices of double or triple drug combinations represent the standard of care. Additionally, existing cell-based model systems, such as Caco-2 cells, are of limited predictive value as they are tumor-derived and do not reprise native epithelium. Thus, there is a need for the development of assay systems that more accurately recapitulate human biology, have higher throughput testing capabilities, and ultimately improve clinical predictability. To this end, we have developed an assay to assess GI toxicity potential using the RepliGut Planar platform, which consists of a primary human stem cell-derived epithelium in a 96-well Transwell format. Quantitative dose-response curves were generated on proliferative and/or differentiated GI cultures for various test articles utilizing endpoints that assess GI proliferative capacity, cell viability, and epithelial barrier formation and maintenance. An initial set of marketed drugs (including diverse anti-proliferative, cytotoxic, or anti-inflammatory mechanisms) with known clinical incidence of diarrhea were over a 5-log dose range to enable modeling of the Toxic Concentration 50% (TC50). When benchmarked against the known human plasma concentrations (Cmax), this model was able to accurately predict clinical outcomes for diarrheagenic-drugs, as well as non-toxic negative controls, within 30-fold of the clinical Cmax. Overall, this model system provides straightforward and informative screening for GI toxicity that integrates sensitive and robust endpoints, enables screening to support early nonclinical development, and uniquely allows for mechanistic insights. Citation Format: James Levi, Reganne Lorichon, Lauren Boone, Maureen Bunger, Elizabeth Boazak, William R. Thelin. A sensitive and specific human primary stem cell-based in vitro assay for predicting the gastrointestinal toxicity risk of therapeutic agents [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 2054.

The growth factor EPIREGULIN promotes basal progenitor cell proliferation in the developing neocortex

Neocortex expansion during evolution is linked to higher numbers of neurons, which are thought to result from increased proliferative capacity and neurogenic potential of basal progenitor cells during development. Here, we show that EREG, encoding the growth factor EPIREGULIN, is expressed in the human developing neocortex and in gorilla cerebral organoids, but not in the mouse neocortex. Addition of EPIREGULIN to the mouse neocortex increases proliferation of basal progenitor cells, whereas EREG ablation in human cortical organoids reduces proliferation in the subventricular zone. Treatment of cortical organoids with EPIREGULIN promotes a further increase in proliferation of gorilla but not of human basal progenitor cells. EPIREGULIN competes with the epidermal growth factor (EGF) to promote proliferation, and inhibition of the EGF receptor abrogates the EPIREGULIN-mediated increase in basal progenitor cells. Finally, we identify putative cis-regulatory elements that may contribute to the observed inter-species differences in EREG expression. Our findings suggest that species-specific regulation of EPIREGULIN expression may contribute to the increased neocortex size of primates by providing a tunable pro-proliferative signal to basal progenitor cells in the subventricular zone.

Interleukin 3 Inhibits Glutamate-Cytotoxicity in Neuroblastoma Cell Line.

Interleukin 3 (IL-3) is a well-known pleiotropic cytokine that regulates the proliferation and differentiation of hematopoietic progenitor cells, triggering classical signaling pathways such as JAK/STAT, Ras/MAPK, and PI3K/Akt to carry out its functions. Interestingly, the IL-3 receptor is also expressed in non-hematopoietic cells, playing a crucial role in cell survival. Our previous research demonstrated the expression of the IL-3 receptor in neuron cells and its protective role in neurodegeneration. Glutamate, a principal neurotransmitter in the central nervous system, can induce cellular stress and lead to neurotoxicity when its extracellular concentrations surpass normal levels. This excessive glutamate presence is frequently observed in various neurological diseases. In this study, we uncover the protective role of IL-3 as an inhibitor of glutamate-induced cell death, analyzing the cytokine's signaling pathways during its protective effect. Specifically, we examined the relevance of JAK/STAT, Ras/MAPK, and PI3 K signaling pathways in the molecular mechanism triggered by IL-3. Our results show that the inhibition of JAK, ERK, and PI3 K signaling pathways, using pharmacological inhibitors, effectively blocked IL-3's protective role against glutamate-induced cell death. Additionally, our findings suggest that Bcl-2 and Bax proteins may be involved in the molecular mechanism triggered by IL-3. Our investigation into IL-3's ability to protect neuronal cells from glutamate-induced damage offers a promising therapeutic avenue with potential clinical implications for several neurological diseases characterized by glutamate neurotoxicity.

Platelet-activating factor receptor (PAFR) regulates neuronal maturation and synaptic transmission during postnatal retinal development.

Platelet-activating factor (PAF), PAF receptor (PAFR), and PAF- synthesis/degradation systems are involved in essential CNS processes such as neuroblast proliferation, differentiation, migration, and synaptic modulation. The retina is an important central nervous system (CNS) tissue for visual information processing. During retinal development, the balance between Retinal Progenitor Cell (RPC) proliferation and differentiation is crucial for proper cell determination and retinogenesis. Despite its importance in retinal development, the effects of PAFR deletion on RPC dynamics are still unknown. We compared PAFR knockout mice (PAFR-/-) retinal postnatal development proliferation and differentiation aspects with control animals. Electrophysiological responses were analyzed by electroretinography (ERG). In this study, we demonstrate that PAFR-/- mice increased proliferation during postnatal retinogenesis and altered the expression of specific differentiation markers. The retinas of postnatal PAFR-/- animals decreased neuronal differentiation and synaptic transmission markers, leading to differential responses to light stimuli measured by ERG. Our findings suggest that PAFR signaling plays a critical role in regulating postnatal RPC cell differentiation dynamics during retinal development, cell organization, and neuronal circuitry formation.

Features of Intracellular Signal Transduction in Neural Stem Cells under the Influence of Alkaloid Songorine, an Agonist of Fibroblast Growth Factor Receptors.

We performed a comparative in vitro study of the involvement of NF-κB, PI3K, cAMP, ERK1/2, p38, JAKs, STAT3, JNK, and p53-dependent intracellular signaling in the functioning of neural stem cells (NSC) under the influence of basic fibroblast growth factor (FGF) and FGF receptor agonist, diterpene alkaloid songorine. The significant differences in FGFR-mediated intracellular signaling in NSC were revealed for these ligands. In both cases, stimulation of progenitor cell proliferation occurs with the participation of NF-κB, PI3K, ERK1/2, JAKs, and STAT3, while JNK and p53, on the contrary, inhibit cell cycle progression. However, under the influence of songorin, cAMP- and p38-mediated cascades are additionally involved in the transmission of the NSC division-activating signal. In addition, unlike FGF, the alkaloid stimulates progenitor cell differentiation by activating ERK1/2, p38, JNK, p53, and STAT3.

A comparative study of morphological and Immunohistochemical expression of P40 and P63 immunomarkers in squamous cell carcinoma and adenocarcinoma lung

Background: Lung cancer is the leading cause of cancer related death worldwide and accounts for 28% of all cancer mortality and around 1.8 million new cases were diagnosed in 2012. The morphological distinction between pulmonary adenocarcinoma (ADC) and squamous cell carcinomas (SCC) is sometimes difficult, mainly in cases of poorly differentiated tumors or when degenerative changes, necrosis and crushing may obscure the cell characteristics. p63 is a homologue of the p53 tumour suppressor gene that is responsible for proliferation and differentiation of epithelial progenitor cells. p40 is consistently the predominant isoform expressed in squamous cell carcinoma; thus, it offers improved specificity for diagnosing squamous cell carcinoma. Material and Methods: This is a prospective and observational study conducted in the Department of Pathology, Tertiary care Teaching Hospital over a period of 1 year. Primary lung carcinoma cases included with unequivocal morphological diagnosis irrespective of age, gender and nature of biopsy material (endoscopic biopsy/ needle core biopsy / resected specimen). Cases diagnosed as Small cell carcinoma of lung, as metastatic lung cancers, poorly differentiated NSCLC-NOS and with inadequate material for IHC study were excluded from present study. Results: In the present study, a total of 150 patients were included out of which 112 (74.6%) were males and 38 (25.4%) were females. In our study, most of the patients were >61 years i.e., 63 out of 150 (42%), followed by 51-60 years, i.e., 40 out of 150 (26.7%). All 8 cases of well differentiated Adenocarcinoma were positive for P40 and 5 cases showed P63 expression. Out of 13 cases of moderately differentiated Adenocarcinoma, 3 cases were positive for P40 and 10 cases were positive for p63 marker. Out of 30 cases of well differentiated Squamous cell carcinoma 15 cases were P40 positive and 15 cases were P63 positive. All 53 cases of moderately differentiated Squamous cell carcinoma showed positive P40 and P63 expression.