Ammonia is a natural waste product of cellular metabolism which, through its lysosomotropic ability, can have detrimental effects on various cellular functions. Increased levels of ammonia were recently detected in the interstitial fluid of various tumours, substantiating that high ammonia concentrations are a pathophysiological condition in the tumour microenvironment, alongside hypoxia and acidosis. Since little is known about how cancer cells respond to elevated levels of ammonia in the tumour microenvironment, we investigated how a panel of cancer cell lines derived from solid tumours behaved when exposed to increasing concentrations of ammonia. We found that ammonia represses cell growth, induces genome instability, and inhibits lysosome-mediated proteolysis in a dose-dependent manner. Unexpectedly, we also found that small fluctuations in the pH of the extracellular environment, had a significant impact on the cytotoxic effects of ammonia. In summary, our data show that the balance of pH and ammonia within the interstitial fluids of cancerous tumours significantly impacts the behaviour and fate of cells residing in the tumour microenvironment.
© 2025. The Author(s).

Intricate crosstalk among various lung cell types is crucial for orchestrating diverse physiological processes. Traditional two-dimensional and recent three-dimensional (3D) assay platforms fail to precisely replicate these complex communications. Many in vitro lung models do not effectively reflect the multicellular complexity of lung tissue. Here, we fabricated an advanced multicellular 3D lung-on-a-chip system that properly replicates the dynamic pulmonary microenvironment and its intricate microarchitecture. Diverse lung cells were incorporated into a microstructure formed from a mixture of natural polymers, including collagen and hyaluronic acid, and blood coagulation factors acting as natural crosslinking agents. The system accurately reflects the complex 3D architecture of the lung. Biomarkers demonstrate more rapid and sensitive responses to toxic substances than functional indicators, such as cell proliferation and apoptosis. SERPINB2 was identified as a biomarker of lung toxicity; it was activated in small airway epithelial cells exposed to various toxic substances. We then developed a fluorescence-linked toxicity biomarker screening platform that enables both intuitive and quantitative evaluation of lung toxicity by measuring the converted fluorescent signal strength. This fluorescent tagging system was incorporated into small airway epithelial cells within a fabricated chip platform; enabling lung-on-a-chip enabled evaluation of the lung toxicity of prospective drug candidates.
© The author(s).

In contrast to adult mammalian hearts, the adult zebrafish heart efficiently replaces cardiomyocytes lost after injury. Here we reveal shared and species-specific injury response pathways and a correlation between Hmga1, an architectural non-histone protein, and regenerative capacity, as Hmga1 is required and sufficient to induce cardiomyocyte proliferation and required for heart regeneration. In addition, Hmga1 was shown to reactivate developmentally silenced genes, likely through modulation of H3K27me3 levels, poising them for a pro-regenerative gene program. Furthermore, AAV-mediated Hmga1 expression in injured adult mouse hearts led to controlled cardiomyocyte proliferation in the border zone and enhanced heart function, without cardiomegaly and adverse remodeling. Histone modification mapping in mouse border zone cardiomyocytes revealed a similar modulation of H3K27me3 marks, consistent with findings in zebrafish. Our study demonstrates that Hmga1 mediates chromatin remodeling and drives a regenerative program, positioning it as a promising therapeutic target to enhance cardiac regeneration after injury.
© 2025. The Author(s).

Vascular complications caused by diabetes mellitus contribute a major threat to increased disability and mortality of diabetic patients, which are characterized by damaged endothelial cells and angiogenesis. Human umbilical cord-derived mesenchymal stem cells (hucMSCs) have been demonstrated to alleviate endothelial cell damage and improve angiogenesis. However, these investigations overlooked the pivotal role of vasculogenesis. In this study, we utilized blood vessel organoids (BVOs) to investigate the impact of high glucose on vasculogenesis and subsequent angiogenesis. We found that BVOs in the vascular lineage induction stage were more sensitive to high glucose and more susceptible to affect endothelial cell differentiation and function. Moreover, hucMSCs can alleviate the high glucose-induced inhibition of endothelial cell differentiation and dysfunction through MAPK signaling pathway downregulation, with the MAPK activator dimethyl fumarate further illustrating the results. Thereby, we demonstrated that high glucose can lead to abnormal vasculogenesis and impact subsequent angiogenesis, and hucMSCs can alleviate this effect.
© 2024 The Author(s).

To explore an alternative strategy to chemotherapy to combat oral cancer, natural products and their derivates constitute one promising approach. In the last previous study, we have demonstrated the potential anti-tumor properties of anethole; an aromatic compound abundantly present in nature that serves as a major active ingredient found in plants like anise and fennel. In the current study, we aimed to investigate how this molecule inhibits oral cancer cell proliferation and induces apoptosis. This will be carried out by a transcriptomic study of its effects on the expression profile of cell cycle and apoptosis regulation genes in gingival cancer cells. cell cycle. Ca9-22 cells were treated with 10 μM of anethole (IC50) and cell proliferation was evaluated by MTT assay. The percentage of cells in different stages of the cell cycle was measured by flow cytometry. Cytotoxicity was evaluated by LDH assay and apoptosis was investigated by Pi/Annexin V assay following 24-hour treatment. Furthermore, we employed PCR array analysis to investigate alterations in the expression levels of oncogenes and tumor suppressor genes associated with cell cycle regulation and apoptosis. Finally, Gene-gene interactions were examined using the Gene MANIA database. Our findings demonstrate that anethole significantly attenuated the proliferation of Ca9-22 cells, leading to disturbances in cell cycle progression and eliciting cellular toxicity and apoptosis. By a double normalizing with two housekeeping genes (Actin and GAPDH), we show that, treatment with 10 μM of anethole alters (more than two-fold) the expression of 13 genes involved in the control of the cell cycle (8 were up regulated and 5 were down regulated) and 7 genes involved in the regulation of apoptosis (4 were up regulated and 3 downregulated by anethole). Finally, each group of genes modulated by anethole forms a network of connections between them or with other genes. Our study suggests that anethole holds promise as a potential alternative treatment for oral cancer by its ability to modify numerous oncogenes and tumor suppressor genes implicated in the cell cycle regulation and induction of apoptosis in oral cancer cells. These findings underscore the significance of further research into the potential therapeutic application of anethole as an alternative drug for managing oral cancer.
Copyright: © 2024 Hammache et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.