Cell Biology International最新文献

Telocytes (TCs), a novel type of mesenchymal or interstitial cell with specific, very long and thin cellular prolongations, have been found in various mammalian organs and have potential biological functions. However, their existence during lung development is poorly understood. This study aimed to investigate the existence, morphological features, and role of CD34⁺ SCs/TCs in mouse lungs from foetal to postnatal life using primary cell culture, double immunofluorescence, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The immunofluorescence double staining profiles revealed positive expression of CD34 and PDGFR-α, Sca-1 or VEGFR-3, and the expression of these markers differed among the age groups during lung development. Intriguingly, in the E18.5 stage of development, along with the CD34⁺ SCs/TCs, haematopoietic stem cells and angiogenic factors were also significantly increased in number compared with those in the E14.5, E16.5, P0 and P7. Subsequently, TEM confirmed that CD34⁺ SCs/TCs consisted of a small cell body with long telopodes (Tps) that projected from the cytoplasm. Tps consisted of alternating thin and thick segments known as podomers and podoms. TCs contain abundant endoplasmic reticulum, mitochondria and secretory vesicles and establish close connections with neighbouring cells. Furthermore, SEM revealed characteristic features, including triangular, oval, spherical, or fusiform cell bodies with extensive cellular prolongations, depending on the number of Tps. Our findings provide evidence for the existence of CD34⁺ SCs/TCs, which contribute to vasculogenesis, the formation of the air‒blood barrier, tissue organization during lung development and homoeostasis.

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy. DEAD/H-box helicase 11 (DDX11), a DNA helicase, has been implicated in the progression of several cancers. Yet, the precise function of DDX11 in OSCC is poorly understood. The DDX11 expression in OSCC cells and normal oral keratinocytes was evaluated in the Gene Expression Omnibus database (GSE146483 and GSE31853). SCC-4 and CAL-27 cells expressing doxycycline-inducible DDX11 or DDX11 shRNA were generated by lentiviral infection. The role of DDX11 in OSCC cells was determined by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, colony formation assay, flow cytometry assay, TUNEL staining, and western blot. The effects of DDX11 on tumor growth were explored in a xenograft nude mouse model. The relationship between DDX11 and transcription factor Yin Yang-1 (YY1) was researched using the dual luciferase report assay and chromatin immunoprecipitation assay. DDX11 expression was significantly upregulated in OSCC cells. Knockdown of DDX11 inhibited cell proliferation, induced cell cycle arrest, and suppressed PI3K-AKT pathway, while DDX11 overexpression showed opposite effects. The number of apoptotic cells was increased in DDX11 silenced cells. DDX11 upregulation or knockdown accelerated or suppressed tumor growth in vivo, respectively. Moreover, the YY1 bound and activated the DDX11 promoter, resulting in increasing DDX11 expression. Forced expression DDX11 reversed the anticancer effects of YY1 silencing on OSCC cells. DDX11 has tumor-promoting function in OSCC and is transcriptionally regulated by YY1, indicating that DDX11 may serve as a potential target for the OSCC treatment.

Corticotropin-releasing hormone (CRH) has been well documented playing a role in the regulation of cellular processes, immune responses, and inflammatory processes that can influence the occurrence and development of tumors. Supervillin (SVIL) is a membrane-associated and actin-binding protein, which is actively involved in the proliferation, spread, and migration of cancer cells. This work investigated CRH's influence on bladder cancer cells' migration and relevant mechanisms. By using human bladder cancer cells T24 and RT4 in wound healing experiments and transwell assay, we found that the migration ability of the T24 cells was significantly increased after CRH treatment. In vivo experiments showed that CRH significantly promoted the metastases of T24 cells in cell line-derived xenograft (CDX) mouse model. Interestingly, downregulation of SVIL by SVIL-specifc small hairpin RNAs significantly reduced the promoting effect of CRH on bladder cancer cell migration. Furthermore, CRH significantly increased SVIL messenger RNA and protein expression in T24 cells, accompanied with AKT and ERK phosphorylation in T24 cells. Pretreatment with AKT inhibitor (MK2206) blocked the CRH-induced SVIL expression and ERK phosphorylation. Also, inhibition of ERK signaling pathway by U0126 significantly reduced the CRH-induced SVIL expression and AKT phosphorylation. It suggested that cross-talking between AKT and ERK pathways was involved in the effect of CRH on SVIL. Taken together, we demonstrated that CRH induced migration of bladder cancer cells, in which AKT and ERK pathways -SVIL played a key role.

Peripheral nerve injury (PNI) often leads to significant functional impairment. Here, we investigated the impact of epidermal growth factor-like domain-containing protein 7 (EGFL7) on angiogenesis and nerve regeneration following PNI. Using a sciatic nerve injury model, we assessed nerve function using the sciatic nerve function index. We analyzed the expression levels of EGFL7, forkhead box proteins A1 (FOXA1), nerve growth factor (NGF), brain-derived neurotrophic factors (BDNF), Neurofilament 200 (NF200), myelin protein zero (P0), cell adhesion molecule 1 (CD31), vascular endothelial growth factor (VEGF), and NOTCH-related proteins in tissues and cells. Cell proliferation, migration, and angiogenesis were evaluated through cell counting kit assays, 5-ethynyl-2′deoxyuridine staining, and Transwell assays. We investigated the binding of FOXA1 to the EGFL7 promoter using dual-luciferase assays and chromatin immunoprecipitation. We observed decreased EGFL7 expression and increased FOXA1 expression in PNI, and EGFL7 overexpression alleviated gastrocnemius muscle atrophy, increased muscle weight, and improved motor function. Additionally, EGFL7 overexpression enhanced Schwann cell and endothelial cell proliferation and migration, promoted tube formation, and upregulated NGF, BDNF, NF200, P0, CD31, and VEGF expression. FOXA1 was found to bind to the EGFL7 promoter region, inhibiting EGFL7 expression and activating the NOTCH signaling pathway. Notably, FOXA1 overexpression counteracted the effects of EGFL7 on Schwann cells and endothelial cells. In conclusion, EGFL7 holds promise as a therapeutic molecule for treating sciatic nerve injury.

The tumor microenvironment (TME) is a critical determinant in the initiation, progression, and treatment outcomes of various cancers. Comprising of cancer-associated fibroblasts (CAF), immune cells, blood vessels, and signaling molecules, the TME is often likened to the soil supporting the seed (tumor). Among its constituents, tumor-associated macrophages (TAMs) play a pivotal role, exhibiting a dual nature as both promoters and inhibitors of tumor growth. This review explores the intricate relationship between TAMs and the TME, emphasizing their diverse functions, from phagocytosis and tissue repair to modulating immune responses. The plasticity of TAMs is highlighted, showcasing their ability to adopt either protumorigenic or anti-tumorigenic phenotypes based on environmental cues. In the context of cancer, TAMs' pro-tumorigenic activities include promoting angiogenesis, inhibiting immune responses, and fostering metastasis. The manuscript delves into therapeutic strategies targeting TAMs, emphasizing the challenges faced in depleting or inhibiting TAMs due to their multifaceted roles. The focus shifts towards reprogramming TAMs to an anti-tumorigenic M1-like phenotype, exploring interventions such as interferons, immune checkpoint inhibitors, and small molecule modulators. Noteworthy advancements include the use of CSF1R inhibitors, CD40 agonists, and CD47 blockade, demonstrating promising results in preclinical and clinical settings. A significant section is dedicated to Chimeric Antigen Receptor (CAR) technology in macrophages (CAR-M cells). While CAR-T cells have shown success in hematological malignancies, their efficacy in solid tumors has been limited. CAR-M cells, engineered to infiltrate solid tumors, are presented as a potential breakthrough, with a focus on their development, challenges, and promising outcomes. The manuscript concludes with the exploration of third-generation CAR-M technology, offering insight into in-vivo reprogramming and nonviral vector approaches. In conclusion, understanding the complex and dynamic role of TAMs in cancer is crucial for developing effective therapeutic strategies. While early-stage TAM-targeted therapies show promise, further extensive research and larger clinical trials are warranted to optimize their targeting and improve overall cancer treatment outcomes.

Exosomes are bilayer lipid bodies and contain a variety of bioactive molecules such as proteins, lipids, and nucleic acids, and so forth. Exosomes derived from solid tumors may play critical roles in tumor development and immune evasion. However, the underlying effects of tumor-derived exosomes on immune function in modulating intercellular crosstalk within the bone marrow niche during acute myeloid leukemia (AML) development and immune evasion remain largely elusive. In this study, we aimed to explore the role of AML-exos in AML immune evasion. First, we isolated tumor-derived exosomes from AML cells (AML-exos) and revealed the presence of programmed cell death ligand-1 (PD-L1) protein in AML-exos. Next, we demonstrated that AML-exos can directly suppress the activation of natural killer (NK) cells and inhibit the cytotoxicity of NK cells, probably through activating the programmed cell death-1 (PD-1)/PD-L1 pathway. Furthermore, the inhibitory effect of AML-exos on NK cells could be alleviated by either PD-L1 inhibitor or antagonist. In summary, we demonstrated that AML-exos possess a PD-L1-dependent tumor-promoting effect which may contribute to immune tolerance in antitumor therapy, but blocking the PD-1/PD-L1 pathway may alleviate the tumor immunosuppression induced by AML-exos. Our findings in this study may offer a new immunotherapy strategy to cure AML.

Pulmonary fibrosis, a debilitating lung disorder characterised by excessive fibrous tissue accumulation in lung parenchyma, compromises respiratory function leading to a life-threatening respiratory failure. While its origins are multifaceted and poorly understood, the urokinase system, including urokinase-type plasminogen activator (uPA) and its receptor (uPAR), plays a significant role in regulating fibrotic response, extracellular matrix remodelling, and tissue repair. Mesenchymal stem/stromal cells (MSCs) hold promise in regenerative medicine for treating pulmonary fibrosis. Our study aimed to investigate the potential of MSCs to inhibit pulmonary fibrosis as well as the contribution of uPAR expression to this effect. We found that intravenous MSC administration significantly reduced lung fibrosis in the bleomycin-induced pulmonary fibrosis model in mice as revealed by MRI and histological evaluations. Notably, administering the MSCs isolated from adipose tissue of uPAR knockout mice (Plaur-/- MSCs) attenuated lung fibrosis to a lesser extent as compared to WT MSCs. Collagen deposition, a hallmark of fibrosis, was markedly reduced in lungs treated with WT MSCs versus Plaur-/- MSCs. Along with that, endogenous uPA levels were affected differently; after Plaur-/- MSCs were administered, the uPA content was specifically decreased within the blood vessels. Our findings support the potential of MSC treatment in attenuating pulmonary fibrosis. We provide evidence that the observed anti-fibrotic effect depends on uPAR expression in MSCs, suggesting that uPAR might counteract the uPA accumulation in lungs.

Adriamycin (ADR) is widely used against breast cancer, but subsequent resistance always occurs. YAP, a downstream protein of angiomotin (AMOT), importantly contributes to ADR resistance, whereas the mechanism is largely unknown. MCF-7 cells and MDA-MB-231 cells were used to establish ADR-resistant cell. Then, mRNA and protein expressions of AMOT and YAP expressions were determined. After AMOT transfection alone or in combination with YAP, the sensitivity of the cells to ADR were evaluated in vitro by examining cell proliferation, apoptosis, and cell cycle, as well as in vivo by examining tumor growth. Additionally, the expressions of proteins in YAP pathway were determined in AMOT-overexpressing cells. In the ADR-resistant cells, the expression of AMOT was decreased while YAP was increased, respectively, and the nucleus localization of YAP was increased at the same time. After AMOT overexpression, these were inhibited, whereas the cell sensitivity to ADR was enhanced. However, the AMOT-induced changes were significantly suppressed by YAP knockdown. The consistent results in vivo showed that AMOT enhanced the inhibition of ADR on tumor growth, and inhibited YAP signaling, evidenced by decreased levels of YAP, CycD1, and p-ERK. Our data revealed that decreased AMOT contributed to ADR resistance in breast cancer cells, which was importantly negatively mediated YAP. These observations provide a potential therapy against breast cancer with ADR resistance.

Migrasome is a newly discovered organelle composed of small vesicular structures enclosed in membrane structures. Since its discovery in 2014, migrasome has attracted increasing attention in cell biology due to its critical role in multiple disease processes. Its pivotal role in various disease processes, including cell migration, intercellular communication, removal of damaged mitochondria, embryogenesis localization, immune cell chemotaxis, and virus transmission, underscores its significance in biological systems. With research on migrasome steadily increasing, it becomes a unique resource for undergraduate cell biology education. For deeper understanding of migrasome, we applied a bibliometric approach. Here we conducted a comprehensive analysis of migrasome research by retrieving relevant literature from databases such as Web of Science, Scopus, and PubMed using the keywords “migrasome” or “migrasomes.” Employing CiteSpace software and Prism, we analyzed annual publication trends, identified core authors and institutions, assessed national contributions, examined keywords, and scrutinized highly cited literature related to migrasome research. This study presents a comprehensive overview of migrasome research, elucidating its literature characteristics, key contributors, research hotspots, and emerging trends. By shedding light on the current status and future trajectories of migrasome research, we aim to provide valuable insights for teachers in cell biology education. We propose for the integration of migrasome research into undergraduate curricula to enhance the understanding of cell biology among premedical, medical, and biomedical students, thereby fostering a deeper appreciation for the intricate mechanisms governing cellular behavior and disease processes.

Microproteins, known as micropeptides, are small protein molecules encoded by short open reading frames. These recently identified molecules have been proven to be an essential part of the human proteome that participates in multiple processes, such as DNA repair, mitochondrial respiration, and regulating different signaling pathways. A growing body of studies has evidenced that microproteins exhibit dysregulated expression levels in various malignancies and contribute to tumor progression. It has been reported that microproteins interact with many proteins, such as enzymes (e.g., adenosine triphosphate synthase) and signal transducers (e.g., c-Jun), and regulate malignant cell metabolism, proliferation, and metastasis. Moreover, microproteins have been found to play a significant role in multidrug resistance in vitro and in vivo by their activity in DNA repair pathways. Considering that, this review intended to summarize the roles of microproteins in different aspects of tumorigenesis with diagnostic and therapeutic perspectives.