A decrease in oxidative phosphorylation (OXPHOS) is characteristic of many cancer types and, in particular, of clear cell renal carcinoma (CCRC) deficient in von Hippel-Lindau (vhl) gene. In the absence of functional pVHL, hypoxia-inducible factor (HIF) 1-alpha and HIF2-alpha subunits are stabilized, which induces the transcription of many genes including those involved in glycolysis and reactive oxygen species (ROS) metabolism. Transfection of these cells with vhl is known to restore HIF-alpha subunit degradation and to reduce glycolytic genes transcription. We show that such transfection with vhl of 786-0 CCRC (which are devoid of HIF1-alpha) also increased the content of respiratory chain subunits. However, the levels of most transcripts encoding OXPHOS subunits were not modified. Inhibition of HIF2-alpha synthesis by RNA interference in pVHL-deficient 786-0 CCRC also restored respiratory chain subunit content and clearly demonstrated a key role of HIF in OXPHOS regulation. In agreement with these observations, stabilization of HIF-alpha subunit by CoCl(2) decreased respiratory chain subunit levels in CCRC cells expressing pVHL. In addition, HIF stimulated ROS production and mitochondrial manganese superoxide dismutase content. OXPHOS subunit content was also decreased by added H(2)O(2.) Interestingly, desferrioxamine (DFO) that also stabilized HIF did not decrease respiratory chain subunit level. While CoCl(2) significantly stimulates ROS production, DFO is known to prevent hydroxyl radical production by inhibiting Fenton reactions. This indicates that the HIF-induced decrease in OXPHOS is at least in part mediated by hydroxyl radical production.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/carcin/bgn125 | DOI Listing |
J Phys Chem B
January 2025
Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Physical vapor deposition is widely used in the fabrication of organic light-emitting diodes and has the potential to adjust the density and orientation through substrate temperature control, which may lead to enhanced electrical performance. However, it is unclear whether this enhanced property is because of the horizontal molecular orientation or the increased density. The effects of the density and orientation on the electrical properties of a potential electron transport material, (3-dibenzo[c,h]acridin-7-yl)phenyl)diphenylphosphine oxide (TPPO-dibenzacridine), were investigated.
View Article and Find Full Text PDFJ Integr Neurosci
January 2025
Department of Hepatology, Federal University of Health Sciences of Porto Alegre (UFCSPA), 90050-170 Porto Alegre, Rio Grande do Sul (RS), Brazil.
Mitochondria are organelles of eukaryotic cells delimited by two membranes and cristae that consume oxygen to produce adenosine triphosphate (ATP), and are involved in the synthesis of vital metabolites, calcium homeostasis, and cell death mechanisms. Strikingly, normal mitochondria function as an integration center between multiple conditions that determine neural cell homeostasis, whereas lesions that lead to mitochondrial dysfunction can desynchronize cellular functions, thus contributing to the pathophysiology of traumatic brain injury (TBI). In addition, TBI leads to impaired coupling of the mitochondrial electron transport system with oxidative phosphorylation that provides most of the energy needed to maintain vital functions, ionic homeostasis, and membrane potentials.
View Article and Find Full Text PDFViruses
January 2025
Antiguo Hospital Civil de Guadalajara, "Fray Antonio Alcalde", Guadalajara 44280, Mexico.
This study investigates the relationship between SARS-CoV-2 RT-PCR cycle threshold (Ct) values and key COVID-19 transmission and outcome metrics across five years of the pandemic in Jalisco, Mexico. Utilizing a comprehensive time-series analysis, we evaluated weekly median Ct values as proxies for viral load and their temporal associations with positivity rates, reproduction numbers (Rt), hospitalizations, and mortality. Cross-correlation and lagged regression analyses revealed significant lead-lag relationships, with declining Ct values consistently preceding surges in positivity rates and hospitalizations, particularly during the early phases of the pandemic.
View Article and Find Full Text PDFPharmaceutics
January 2025
Key Laboratory of Basic and Application Research of Beiyao (Heilongjiang University of Chinese Medicine), Ministry of Education, 24 Heping Road, Harbin 150040, China.
: (PG) has been widely researched as a conductant drug for the treatment of lung diseases by ancient and modern traditional Chinese medicine (TCM) practitioners. Inspired by the mechanism and our previous finding about fructans and fructooligosaccharides from (FFPG), we developed a nano drug delivery system (NDDS) targeting lung cancer. The aim was to improve the efficiency of the liposomal delivery of Paclitaxel (PTX) and enhance the anti-tumor efficacy.
View Article and Find Full Text PDFPlants (Basel)
January 2025
School of Life Sciences, Fudan University, Shanghai 200433, China.
: The functional traits of twigs and leaves are closely related to the ability of plants to cope with heterogeneous environments. The analysis of the characteristics of twigs and leaves and leaf thermal dissipation in riparian plants is of great significance for exploring the light energy allocation and ecological adaptation strategies of plant leaves in heterogeneous habitats. However, there are few studies on the correlation between the twig-leaf characteristics of riparian plants and their heat dissipation in light heterogeneous environments.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!