Early-passage human diploid fibroblasts (HDFs) undergo senescence-like growth arrest in response to sublethal concentrations of H(2)O(2) [Chen and Ames (1994) Proc. Natl. Acad. Sci. USA. 95, 4130-4134]. We determine here whether H(2)O(2) can cause apoptosis in HDFs and the molecular changes that differ between apoptosis and senescence-like growth arrest. When exponentially growing early-passage IMR-90 cells were treated for 2 h with 50-200 microM (or 0.25-1 pmol/cell) H(2)O(2), a fraction of cells detached at 16-32 h after the treatment. The cells remaining attached were growth-arrested and developed features of senescence in 1 week. The detached cells showed caspase-3 activation and typical morphological changes associated with apoptosis. Caspase-3 activation was H(2)O(2) dose-dependent and preceded nuclear condensation or plasma membrane leakage. Apoptotic cells were mainly distributed in the S-phase of the cell cycle, while growth-arrested cells exhibited predominantly G1- and G2/M-phase distributions. H(2)O(2) pretreatment induced G1 arrest and prohibited induction of apoptosis by a subsequent H(2)O(2) challenge. The p53 protein showed an average 6.1-fold elevation in apoptotic cells and a 3.5-fold elevation in growth-arrested cells. Reduction of p53 levels with human papillomavirus E6 protein prohibited the activation of caspase-3 and decreased the proportion of apoptotic cells. Growth-arrested cells had elevated p21, while p21 was absent in apoptotic cells. Bcl-2 was elevated in both growth-arrested and apoptotic cells. Finally, although the overall level of bax did not change in growth-arrested or apoptotic cells, the solubility of bax protein increased in apoptotic cells. Our data suggest that in contrast with growth-arrested cells, apoptotic cells show an S-phase cell cycle distribution, a higher degree of p53 elevation, an absence of p21 protein and increased solubility of bax protein.
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http://dx.doi.org/10.1042/0264-6021:3470543 | DOI Listing |
Neurochem Res
January 2025
Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
In recent decades, researchers and clinicians have increasingly focused on glial cell function. One of the primary mechanisms influencing these functions is through extracellular vesicles (EVs), membrane-bound particles released by cells that are essential for intercellular communication. EVs can be broadly categorized into four main types based on their size, origin, and biogenesis: large EVs, small EVs (sEVs), autophagic EVs, and apoptotic bodies.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Organosilicon Chemistry and Materials Technology of the Ministry of Education, Zhejiang Key Laboratory of Organosilicon Material Technology, College of Materials, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, P. R. China.
As many treatments kill tumor cells by inducing apoptosis, fluorescent probes that can detect apoptosis are crucial for effective feedback regarding tumor therapy outcomes (in particular, activatable probes for better imaging). Cathepsins are enzymes that are released from lysosomes into the cytoplasm during lysosomal membrane permeabilization-induced apoptosis of many tumor cells, making them potential biomarkers of apoptotic cells. Despite their potential, to the best of our knowledge, no cathepsin-activatable fluorescent probes have been reported for this purpose.
View Article and Find Full Text PDFBMC Oral Health
January 2025
Oral Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.
Background: Calretinin is a 29 kilodalton (KDa) calcium-binding protein that is expressed in normal and tumoral tissues. The expression of calretinin has been shown in the dental epithelium during odontogenesis and in different odontogenic cysts and tumors such as ameloblastoma. Since the epithelium of calcifying odontogenic cyst (COC) is similar to ameloblastoma and in both lesions, an arrangement of loose cells similar to stellate reticulum is seen, we aimed to investigate the comparative expression of calretinin in COC and ameloblastoma.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Urology, Affiliated Hospital of Youjiang Medical University for Nationalities and Key Laboratory of Molecular Pathology in Tumors of Baise, Baise 533000, China. Electronic address:
The primary objective of this study was to conduct a comprehensive analysis of the mechanism by which TCF7 recombinant protein operates, as well as to examine its expression patterns within bladder cancer cells. This research seeks to establish a new theoretical framework and provide experimental data that could advance the field of molecular targeted therapy for bladder cancer. Erlotinib, a well-known targeted therapy drug, was administered to the bladder cancer cells, and we evaluated its antitumor effects through various assays such as cell proliferation, apoptosis, and cell cycle analysis.
View Article and Find Full Text PDFPLoS One
January 2025
Precision Laboratory of Vascular Medicine, Shanxi Cardiovascular Hospital Affiliated Shanxi Medical University, Taiyuan, PR China.
Background: Myocardial ischemia-reperfusion injury (MIRI) is an important complication in the treatment of heart failure, and its treatment has not made satisfactory progress. Nitroxyl (HNO) showed protective effects on the heart failure, however, the effect and underlying mechanism of HNO on MIRI remain largely unclear.
Methods: MIRI model in this study was established to induce H9C2 cell injury through hypoxia/reoxygenation (H/R) in vitro.
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