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EvoDevo Jun 2022There are a wide range of developmental strategies in animal phyla, but most insights into adult body plan formation come from direct-developing species. For...
BACKGROUND
There are a wide range of developmental strategies in animal phyla, but most insights into adult body plan formation come from direct-developing species. For indirect-developing species, there are distinct larval and adult body plans that are linked together by metamorphosis. Some outstanding questions in the development of indirect-developing organisms include the extent to which larval tissue undergoes cell death during the process of metamorphosis and when and where the tissue that will give rise to the adult originates. How do the processes of cell division and cell death redesign the body plans of indirect developers? In this study, we present patterns of cell proliferation and cell death during larval body plan development, metamorphosis, and adult body plan formation, in the hemichordate Schizocardium californium (Cameron and Perez in Zootaxa 3569:79-88, 2012) to answer these questions.
RESULTS
We identified distinct patterns of cell proliferation between larval and adult body plan formation of S. californicum. We found that some adult tissues proliferate during the late larval phase prior to the start of overt metamorphosis. In addition, using an irradiation and transcriptomic approach, we describe a genetic signature of proliferative cells that is shared across the life history states, as well as markers that are unique to larval or juvenile states. Finally, we observed that cell death is minimal in larval stages but begins with the onset of metamorphosis.
CONCLUSIONS
Cell proliferation during the development of S. californicum has distinct patterns in the formation of larval and adult body plans. However, cell death is very limited in larvae and begins during the onset of metamorphosis and into early juvenile development in specific domains. The populations of cells that proliferated and gave rise to the larvae and juveniles have a genetic signature that suggested a heterogeneous pool of proliferative progenitors, rather than a set-aside population of pluripotent cells. Taken together, we propose that the gradual morphological transformation of S. californicum is mirrored at the cellular level and may be more representative of the development strategies that characterize metamorphosis in many metazoan animals.
PubMed: 35668535
DOI: 10.1186/s13227-022-00198-1 -
Stem Cell Research & Therapy Jan 2021Adult mammalian retinal stem cells (RSCs) readily proliferate, self-renew, and generate progeny that differentiate into all retinal cell types in vitro. RSC-derived...
BACKGROUND
Adult mammalian retinal stem cells (RSCs) readily proliferate, self-renew, and generate progeny that differentiate into all retinal cell types in vitro. RSC-derived progeny can be induced to differentiate into photoreceptors, making them a potential source for retinal cell transplant therapies. Despite their proliferative propensity in vitro, RSCs in the adult mammalian eye do not proliferate and do not have a regenerative response to injury. Thus, identifying and modulating the mechanisms that regulate RSC proliferation may enhance the capacity to produce RSC-derived progeny in vitro and enable RSC activation in vivo.
METHODS
Here, we used medium-throughput screening to identify small molecules that can expand the number of RSCs and their progeny in culture. In vitro differentiation assays were used to assess the effects of synthetic glucocorticoid agonist dexamethasone on RSC-derived progenitor cell fate. Intravitreal injections of dexamethasone into adult mouse eyes were used to investigate the effects on endogenous RSCs.
RESULTS
We discovered that high-affinity synthetic glucocorticoid agonists increase RSC self-renewal and increase retinal progenitor proliferation up to 6-fold without influencing their differentiation in vitro. Intravitreal injection of synthetic glucocorticoid agonist dexamethasone induced in vivo proliferation in the ciliary epithelium-the niche in which adult RSCs reside.
CONCLUSIONS
Together, our results identify glucocorticoids as novel regulators of retinal stem and progenitor cell proliferation in culture and provide evidence that GCs may activate endogenous RSCs.
Topics: Animals; Cell Differentiation; Cell Proliferation; Cell Self Renewal; Cells, Cultured; Glucocorticoids; Mice; Retina
PubMed: 33494791
DOI: 10.1186/s13287-021-02136-9 -
Molecular and Clinical Oncology Sep 2022Infantile hemangioma is a common benign tumor in infants. However, the molecular mechanism that controls the proliferation and differentiation of hemangioma is not well...
Infantile hemangioma is a common benign tumor in infants. However, the molecular mechanism that controls the proliferation and differentiation of hemangioma is not well understood. Annexin A1 (ANX A1) is a phospholipid-binding protein involved in a variety of biological processes, including inflammation, cell proliferation and apoptosis. To explore the significance of ANX A1 in the process of proliferation or differentiation of hemangioma, proliferating and involuting hemangioma tissues were collected to detect the expression of ANX A1 using immunohistochemistry and western blotting. Normal skin tissues were used as the negative control. The results revealed that ANX A1 was upregulated in the proliferative phase of hemangioma, and its expression was decreased when the hemangioma entered the involuting phase. Additionally, in the proliferative phase, the strongest staining of ANX A1 was observed in newly born capillaries, and the staining of ANX A1 became weaker in enlarged vessels, indicating that ANX A1 plays an important role in promoting the formation of capillaries. The expression of hypoxia-inducible factor (HIF)-1α was positively associated with the expression trend of ANX A1, suggesting that the overexpression of ANX A1 may be associated with the increase of HIF-1α. In summary, the results of the present study revealed that the expression of ANX A1 was increased in proliferating hemangioma tissue, and that high expression of ANX A1 may be closely associated with the formation of capillaries in infantile hemangioma.
PubMed: 35949889
DOI: 10.3892/mco.2022.2566 -
RSPO2 as Wnt signaling enabler: Important roles in cancer development and therapeutic opportunities.Genes & Diseases Mar 2024R-spondins are secretory proteins localized in the endoplasmic reticulum and Golgi bodies and are processed through the secretory pathway. Among the R-spondin family,... (Review)
Review
R-spondins are secretory proteins localized in the endoplasmic reticulum and Golgi bodies and are processed through the secretory pathway. Among the R-spondin family, RSPO2 has emanated as a novel regulator of Wnt signaling, which has now been acknowledged in numerous and studies. Cancer is an abnormal growth of cells that proliferates and spreads uncontrollably due to the accumulation of genetic and epigenetic factors that constitutively activate Wnt signaling in various types of cancer. Colorectal cancer (CRC) begins when cells in the colon and rectum follow an indefinite pattern of division due to aberrant Wnt activation as one of the key hallmarks. Decades-long progress in research on R-spondins has demonstrated their oncogenic function in distinct cancer types, particularly CRC. As a critical regulator of the Wnt pathway, it modulates several phenotypes of cells, such as cell proliferation, invasion, migration, and cancer stem cell properties. Recently, RSPO mutations, gene rearrangements, fusions, copy number alterations, and altered gene expression have also been identified in a variety of cancers, including CRC. In this review, we addressed the recent updates regarding the recurrently altered R-spondins with special emphasis on the RSPO2 gene and its involvement in potentiating Wnt signaling in CRC. In addition to the compelling physiological and biological roles in cellular fate and regulation, we propose that RSPO2 would be valuable as a potential biomarker for prognostic, diagnostic, and therapeutic use in CRC.
PubMed: 37692504
DOI: 10.1016/j.gendis.2023.01.013 -
Frontiers in Endocrinology 2022Male reproductive function depends on the formation of spermatogonial stem cells from their neonatal precursors, the gonocytes. Previously, we identified several UPS...
Male reproductive function depends on the formation of spermatogonial stem cells from their neonatal precursors, the gonocytes. Previously, we identified several UPS enzymes dynamically altered during gonocyte differentiation. The present work focuses on understanding the role of the RING finger protein 149 (RNF149), an E3 ligase that we found to be strongly expressed in gonocytes and downregulated in spermatogonia. The quantification of RNF149 mRNA from postnatal day (PND) 2 to 35 (puberty) in rat testis, brain, liver, kidney, and heart indicated that its highest levels are found in the testis. RNF149 knock-down in PND3 rat gonocytes was performed to better understand its role in gonocyte development. While a proliferative cocktail of PDGF-BB and 17β-estradiol (P+E) increased both the expression levels of the cell proliferation marker PCNA and RNF149 in mock cells, the effects of P+E on both genes were reduced in cells treated with RNF149 siRNA, suggesting that RNF149 expression is regulated during gonocyte proliferation and that there might be a functional link between RNF149 and PCNA. To examine RNF149 subcellular localization, EGFP-tagged RNF149 vectors were constructed, after determining the rat testis RNF149 mRNA sequence. Surprisingly, two variant transcripts were expressed in rat tissues, predicting truncated proteins, one containing the PA and the other the RING functional domains. Transfection in mouse F9 embryonal carcinoma cells and C18-4 spermatogonial cell lines showed differential subcellular profiles of the two truncated proteins. Overall, the results of this study support a role for RNF149 in gonocyte proliferation and suggest its transcription to variant mRNAs resulting in two proteins with different functional domains. Future studies will examine the respective roles of these variant proteins in the cell lines and isolated gonocytes.
Topics: Animals; Male; Mice; Proliferating Cell Nuclear Antigen; RNA, Messenger; Rats; Rats, Sprague-Dawley; Sexual Maturation; Spermatogonia; Ubiquitin; Ubiquitin-Protein Ligases
PubMed: 35634494
DOI: 10.3389/fendo.2022.896507 -
Journal of B.U.ON. : Official Journal... 2021To investigate the expressions of CD44 non-small cell lung cancer cells, proliferating cell nuclear antigen (PCNA) and multidrug resistance-associated protein 1 (MRP1)...
PURPOSE
To investigate the expressions of CD44 non-small cell lung cancer cells, proliferating cell nuclear antigen (PCNA) and multidrug resistance-associated protein 1 (MRP1) in the lung cancer tissues and their effects on the proliferation and invasion abilities in vitro of lung cancer cell line 95D.
METHODS
138 lung cancer tissues and 127 adjacent normal tissues were collected from lung cancer patients after operation in Shandong Provincial Third Hospital from January 2015 to December 2017. CD44 siRNA (experimental CD44 group), PCNA siRNA (experimental PCNA group) and MRP1 siRNA (experimental MRP1 group) were transfected into human lung cancer 95D cells, and a negative control group (cells transfected with miR-Native Control) and a blank group (untransfected cells) were established. MTT assay was used for detecting the proliferation of cells, and Transwell chamber was used for detecting their invasion ability.
RESULTS
The relative expressions of CD44, PCNA and MRP1 in the lung cancer tissues were higher than those in the adjacent tissues (p<0.050). At 24th h, the cell survival rate in the experimental MRP1 group was lower than that in the experimental PCNA group (p<0.050); At 48th the cell survival rate in the experimental MRP1 group was higher than that in the experimental CD44 group (p<0.050). At 72th h, the cell survival rate in the experimental PCNA group was significantly higher than that in the experimental CD44 group and the experimental MRP1 group (p<0.05). The cell invasion number in the experimental CD44 group, the experimental PCNA group and the experimental MRP1 group were significantly lower than cells in the negative control group and blank group (p<0.05).
CONCLUSION
CD44, PCNA and MRP1, which may be involved in the regulation of the proliferation and invasion abilities of lung cancer cells, may serve as new molecular targeting markers for the diagnosis and treatment of lung cancer.
Topics: Cell Line, Tumor; Cell Proliferation; Female; Humans; Hyaluronan Receptors; Lung Neoplasms; Multidrug Resistance-Associated Proteins; Proliferating Cell Nuclear Antigen
PubMed: 33721434
DOI: No ID Found -
Scientific Reports Jan 2021Generating the proliferation of differentiated normal adult human hepatocytes is a major challenge and an expected central step in understanding the microenvironmental...
Generating the proliferation of differentiated normal adult human hepatocytes is a major challenge and an expected central step in understanding the microenvironmental conditions that regulate the phenotype of human hepatocytes in vitro. In this work, we described optimized 3D culture conditions of primary human hepatocytes (PHH) to trigger two waves of proliferation and we identified matrix stiffness and cell-cell interactions as the main actors necessary for this proliferation. We demonstrated that DNA replication and overexpression of cell cycle markers are modulate by the matrix stiffness while PHH cultured in 3D without prior cellular interactions did not proliferate. Besides, we showed that PHH carry out an additional cell cycle after transient inhibition of MAPK MER1/2-ERK1/2 signaling pathway. Collagen cultured hepatocytes are organized as characteristic hollow spheroids able to maintain survival, cell polarity and hepatic differentiation for long-term culture periods of at least 28 days. Remarkably, we demonstrated by transcriptomic analysis and functional experiments that proliferating cells are mature hepatocytes with high detoxication capacities. In conclusion, the advanced 3D model described here, named Hepoid, is particularly relevant for obtaining normal human proliferating hepatocytes. By allowing concomitant proliferation and differentiation, it constitutes a promising tool for many pharmacological and biotechnological applications.
Topics: Cell Communication; Cell Culture Techniques; Cell Cycle; Cell Differentiation; Cell Polarity; Cell Proliferation; Cell Survival; Cells, Cultured; Collagen; DNA Replication; Elasticity; Hepatocytes; Humans; MAP Kinase Signaling System; Spheroids, Cellular
PubMed: 33436872
DOI: 10.1038/s41598-020-80019-4 -
FEBS Open Bio Dec 2022When skeletal muscle is damaged, satellite cells (SCs) are activated to proliferate rapidly and fuse with the damaged muscle fibers to form new muscle fibers, thereby...
When skeletal muscle is damaged, satellite cells (SCs) are activated to proliferate rapidly and fuse with the damaged muscle fibers to form new muscle fibers, thereby promoting muscle growth and remodeling and repair of trauma. Exosomes from differentiating human skeletal muscle cells trigger myogenesis of stem cells and provide biochemical cues for skeletal muscle regeneration. Therefore, we hypothesized that, when muscles are injured, myoblast-derived exosomes may regulate muscle repair and regeneration. Here, we investigated the underlying mechanism by applying C2C12-derived exosomes to injured mouse skeletal muscles. The expression levels of skeletal muscle regeneration factors paired box 7 and lipid-promoting factor peroxisome proliferator-activated receptor γ were upregulated, whereas the expression levels of fibrosis factors collagen-1 and α-smooth muscle actin decreased. The expression of proliferating cell nuclear antigen was elevated after applying C2C12-derived exosomes to SCs. Application of C2C12-derived exosomes to fibro-adipogenic progenitors resulted in an increase in peroxisome proliferator-activated receptor γ expression and adipogenesis capacity, whereas α-smooth muscle actin expression and fibrosis capacity decreased. Analysis of the transcriptome and proteome of SCs after treatment with exosomes showed the involvement of multiple biological processes, including proliferation and differentiation of SCs, muscle regeneration, skeletal muscle atrophy, and the inflammatory response after muscle injury. Hence, our data suggest that C2C12-derived exosomes can promote the regeneration of skeletal muscle fibers, accelerate the production of fat from damaged muscles, inhibit the fibrosis of damaged muscles, and accelerate injury repair, which is related to exosome-mediated regulation of the proliferation of SCs, differentiation of fibro-adipogenic progenitors, and modulation of SC mRNA expression and protein formation and decomposition.
Topics: Mice; Humans; Animals; Exosomes; PPAR gamma; Actins; Myoblasts; Muscle, Skeletal; Fibrosis
PubMed: 36325691
DOI: 10.1002/2211-5463.13504 -
Burns & Trauma 2020Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion. These pathological behaviours may be related to the...
BACKGROUND
Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion. These pathological behaviours may be related to the heterogeneity of keloid fibroblasts (KFs); however, because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism. Our previous studies revealed that the expansion of CD26 KFs was responsible for increased keloid proliferation and invasion capabilities; the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation. The aim of this study was to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities, and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.
METHODS
Flow cytometry was performed to isolate CD26/CD26 fibroblasts from KFs and normal fibroblasts. To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor (IGF-1R), lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection. Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay. Scratching assay and transwell assay were used to assess cell migration and invasion abilities. To further quantify the regulatory role of CD26 expression in the relevant signalling pathway, RT-qPCR, western blot, ELISA, PI3K activity assay and immunofluorescence were used.
RESULTS
Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs. Furthermore, the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion. The PI3K/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.
CONCLUSIONS
CD26 can be the effective biomarker for KFs, and its expression is closely related to proliferation and invasion in keloids through the IGF-1-induced PI3K/AKT/mTOR pathway. This work provides a novel perspective on the pathological mechanisms affecting KFs and therapeutic strategies against keloids.
PubMed: 33150188
DOI: 10.1093/burnst/tkaa025 -
Frontiers in Cellular and Infection... 2023Tapeworm larvae cause important diseases in humans and domestic animals. During infection, the first larval stage undergoes a metamorphosis where tissues are formed...
BACKGROUND
Tapeworm larvae cause important diseases in humans and domestic animals. During infection, the first larval stage undergoes a metamorphosis where tissues are formed from a population of stem cells called germinative cells. This process is difficult to study for human pathogens, as these larvae are infectious and difficult to obtain in the laboratory.
METHODS
In this work, we analyzed cell proliferation and differentiation during larval metamorphosis in the model tapeworm , by labelling of proliferating cells with the thymidine analogue 5-ethynyl-2'-deoxyuridine (EdU), tracing their differentiation with a suite of specific molecular markers for different cell types.
RESULTS
Proliferating cells are very abundant and fast-cycling during early metamorphosis: the total number of cells duplicates every ten hours, and the length of G2 is only 75 minutes. New tegumental, muscle and nerve cells differentiate from this pool of proliferating germinative cells, and these processes are very fast, as differentiation markers for neurons and muscle cells appear within 24 hours after exiting the cell cycle, and fusion of new cells to the tegumental syncytium can be detected after only 4 hours. Tegumental and muscle cells appear from early stages of metamorphosis (24 to 48 hours post-infection); in contrast, most markers for differentiating neurons appear later, and the detection of synapsin and neuropeptides correlates with scolex retraction. Finally, we identified populations of proliferating cells that express conserved genes associated with neuronal progenitors and precursors, suggesting the existence of tissue-specific lineages among germinative cells.
DISCUSSION
These results provide for the first time a comprehensive view of the development of new tissues during tapeworm larval metamorphosis, providing a framework for similar studies in human and veterinary pathogens.
Topics: Animals; Humans; Hymenolepis; Metamorphosis, Biological; Cell Differentiation; Muscles; Cell Proliferation; Larva
PubMed: 37908761
DOI: 10.3389/fcimb.2023.1286190