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Experimental & Molecular Medicine Mar 2023Vascular calcification is a serious complication of hyperphosphatemia that causes cardiovascular morbidity and mortality. Previous studies have reported that...
Vascular calcification is a serious complication of hyperphosphatemia that causes cardiovascular morbidity and mortality. Previous studies have reported that plasmalemmal phosphate (Pi) transporters, such as PiT-1/2, mediate depolarization, Ca influx, oxidative stress, and calcific changes in vascular smooth muscle cells (VSMCs). However, the pathogenic mechanism of mitochondrial Pi uptake in vascular calcification associated with hyperphosphatemia has not been elucidated. We demonstrated that the phosphate carrier (PiC) is the dominant mitochondrial Pi transporter responsible for high Pi-induced superoxide generation, osteogenic gene upregulation, and calcific changes in primary VSMCs isolated from rat aortas. Notably, acute incubation with high Pi markedly increased the protein abundance of PiC via ERK1/2- and mTOR-dependent translational upregulation. Genetic suppression of PiC prevented Pi-induced ERK1/2 activation, superoxide production, osteogenic differentiation, and vascular calcification of VSMCs in vitro and aortic rings ex vivo. Pharmacological inhibition of mitochondrial Pi transport using butyl malonate (BMA) or mersalyl abolished all pathologic changes involved in high Pi-induced vascular calcification. BMA or mersalyl also effectively prevented osteogenic gene upregulation and calcification of aortas from 5/6 subtotal nephrectomized mice fed a high-Pi diet. Our results suggest that mitochondrial Pi uptake via PiC is a critical molecular mechanism mediating mitochondrial superoxide generation and pathogenic calcific changes, which could be a novel therapeutic target for treating vascular calcification associated with hyperphosphatemia.
Topics: Rats; Mice; Animals; Hyperphosphatemia; Cells, Cultured; Superoxides; Osteogenesis; Mersalyl; Phosphates; Vascular Calcification; Phosphate Transport Proteins; Myocytes, Smooth Muscle
PubMed: 36854772
DOI: 10.1038/s12276-023-00950-0 -
BioMed Research International 2022One of the globally common cancers is colorectal cancer (CRC). At present, a surgical approach remains a good option for CRC patients; however, 20% of surgically treated...
One of the globally common cancers is colorectal cancer (CRC). At present, a surgical approach remains a good option for CRC patients; however, 20% of surgically treated CRC patients experience metastasis. Currently, even the first-line used drug, oxaliplatin, remains inadequate for treating metastatic CRC, and its side effect of neurotoxicity is a major problem when treating CRC. The Gene Omnibus GSE42387 database contains gene expression profiles of parental and oxaliplatin-resistant LoVo cell lines. Differentially expressed genes (DEGs) between parental and oxaliplatin-resistance LoVo cells, protein-protein interactions (PPIs), and a pathway analysis were determined to identify overall biological changes by an online DAVID bioinformatics analysis. The ability of DEGs to predict overall survival (OS) and disease-free survival (DFS) was validated by the SPSS 22.0, using liver metastasis CRC patient samples of GSE41258. The bioinformatics web tools of the GEPIA, the Human Protein Atlas, WebGestalt, and TIMER platforms were used. In total, 218 DEGs were identified, among which 105 were downregulated and 113 were upregulated. After mapping the PPI networks and pathways, 60 DEGs were identified as hub genes (with high degrees). Six genes (, , , , , and ) were involved with malaria, PPAR signaling, and the adipocytokine signaling pathway. High expressions of and were associated with the poor survival of CRC patients in the GSE41258 database. We predicted specific micro (mi)RNAs that targeted the 3' untranslated region (UTR) of by using miRWalk. It was found that three miRNAs, viz., miR-7-5p, miR-20a-3p, and miR-636, may be upstream targets of those genes. High expression levels of miR-7-5p, miR-20a-3p, and miR-636 were associated with poor OS of CRC patients, and the small-molecule compound, mersalyl, is a promising drug for treating oxaliplatin-resistant CRC. In conclusion, miR-7-5p miR-20a-3p, and miR-636 targeted the PCK1 biomarker in the PPAR signaling pathway, which is involved in oxaliplatin-resistant CRC. Meanwhile, mersalyl was identified as a potential drug for overcoming oxaliplatin resistance in CRC. Our findings may provide novel directions and strategies for CRC therapies.
Topics: 3' Untranslated Regions; Adipokines; Biomarkers; Colonic Neoplasms; Colorectal Neoplasms; Gene Expression Regulation, Neoplastic; Humans; Mersalyl; MicroRNAs; Oxaliplatin; Peroxisome Proliferator-Activated Receptors; Signal Transduction
PubMed: 36193307
DOI: 10.1155/2022/3825760 -
International Journal of Molecular... Jan 2023Lysine residues are essential in regulating enzymatic activity and the spatial structure maintenance of mitochondrial proteins and functional complexes. The most... (Comparative Study)
Comparative Study
A Comparative Study on the Effects of the Lysine Reagent Pyridoxal 5-Phosphate and Some Thiol Reagents in Opening the Tl-Induced Mitochondrial Permeability Transition Pore.
Lysine residues are essential in regulating enzymatic activity and the spatial structure maintenance of mitochondrial proteins and functional complexes. The most important parts of the mitochondrial permeability transition pore are F1F0 ATPase, the adenine nucleotide translocase (ANT), and the inorganic phosphate cotransporter. The ANT conformation play a significant role in the Tl-induced MPTP opening in the inner membrane of calcium-loaded rat liver mitochondria. The present study tests the effects of a lysine reagent, pyridoxal 5-phosphate (PLP), and thiol reagents (phenylarsine oxide, tert-butylhydroperoxide, eosin-5-maleimide, and mersalyl) to induce the MPTP opening that was accompanied by increased swelling, membrane potential decline, and decreased respiration in 3 and 3U (2,4-dinitrophenol uncoupled) states. This pore opening was more noticeable in increasing the concentration of PLP and thiol reagents. However, more significant concentrations of PLP were required to induce the above effects comparable to those of these thiol reagents. This study suggests that the Tl-induced MPTP opening can be associated not only with the state of functionally active cysteines of the pore parts, but may be due to a change in the state of the corresponding lysines forming the pore structure.
Topics: Animals; Rats; Calcium; Indicators and Reagents; Lysine; Mitochondria, Liver; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Permeability; Pyridoxal Phosphate; Rats, Wistar; Sulfhydryl Reagents; Thallium
PubMed: 36768782
DOI: 10.3390/ijms24032460 -
International Journal of Molecular... Jul 2018The idea of using metabolic aberrations as targets for diagnosis or therapeutic intervention has recently gained increasing interest. In a previous study, our group...
The idea of using metabolic aberrations as targets for diagnosis or therapeutic intervention has recently gained increasing interest. In a previous study, our group discovered intriguing differences in the oxidative mitochondrial respiration capacity of benign and prostate cancer (PCa) cells. In particular, we found that PCa cells had a higher total respiratory activity than benign cells. Moreover, PCa cells showed a substantial shift towards succinate-supported mitochondrial respiration compared to benign cells, indicating a re-programming of respiratory control. This study aimed to investigate the role of succinate and its main plasma membrane transporter NaDC3 (sodium-dependent dicarboxylate transporter member 3) in PCa cells and to determine whether targeting succinate metabolism can be potentially used to inhibit PCa cell growth. Using high-resolution respirometry analysis, we observed that ROUTINE respiration in viable cells and succinate-supported respiration in permeabilized cells was higher in cells lacking the tumor suppressor phosphatase and tensin-homolog deleted on chromosome 10 (PTEN), which is frequently lost in PCa. In addition, loss of PTEN was associated with increased intracellular succinate accumulation and higher expression of NaDC3. However, siRNA-mediated knockdown of NaDC3 only moderately influenced succinate metabolism and did not affect PCa cell growth. By contrast, mersalyl acid-a broad acting inhibitor of dicarboxylic acid carriers-strongly interfered with intracellular succinate levels and resulted in reduced numbers of PCa cells. These findings suggest that blocking NaDC3 alone is insufficient to intervene with altered succinate metabolism associated with PCa. In conclusion, our data provide evidence that loss of PTEN is associated with increased succinate accumulation and enhanced succinate-supported respiration, which cannot be overcome by inhibiting the succinate transporter NaDC3 alone.
Topics: Cell Line, Tumor; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Mitochondria; Oxidative Phosphorylation; PTEN Phosphohydrolase; Prostatic Neoplasms; Respiration; Succinic Acid
PubMed: 30037119
DOI: 10.3390/ijms19072129