Journal of Bioenergetics and Biomembranes最新文献

Bacillus licheniformis can use cyanide as a nitrogen source for its growth. However, it can also carry out aerobic respiration in the presence of this compound, a classic inhibitor of mammalian cytochrome c oxidase, indicating that B. licheniformis has a branched respiratory chain with various terminal oxidases. Here, we studied the modifications in the respiratory chain of B. licheniformis when cells were cultured in Nutrient Broth, an alkaline medium with ammonium, or an alkaline medium with cyanide. Then, we measured oxygen consumption in intact cells and membranes, enzyme activities, carried out 1D and 2D-BN-PAGE, followed by mass spectrometry analysis of BN-PAGE bands associated with NADH, NADPH, and succinate dehydrogenase activities. We found that cell growth was favored in a nutrient medium than in an alkaline medium with cyanide. In parallel, respiratory activity progressively decreased in cells cultured in the rich medium, alkaline medium with ammonium, and the lowest activity was in the cells growing in the alkaline medium with cyanide. B. licheniformis membranes contain NADH, NADPH, and succinate dehydrogenases, and the proteomic analysis detected the nitrate reductase and the bc, caa3, aa3, and bd complexes. The succinate dehydrogenase migrated with a molecular mass of 375 kDa, indicating its association with the nitrate reductase (115 kDa + 241 kDa, respectively). The NADH dehydrogenase of B. licheniformis forms aggregates of different molecular mass.

N⁶-methyladenosine (m⁶A) modification is, a more common epigenetic modification, mainly found in mRNA. More and more researches have shown the important functions of m⁶A on human cancers. This study seeks to explore the role of hnRNPA2B1 and m⁶A-dependent mechanism in cervical cancer. Elevated hnRNPA2B1 indicated the poor prognosis of cervical cancer patients. Enforced hnRNPA2B1 reduced the apoptosis, and accelerated the proliferation and migration of cervical cancer cells in vitro. Besides, hnRNPA2B1 promoted the aerobic glycolysis of cervical cancer cells, including the lactate secretion, glucose uptake, ATP production, extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). LDHA was found as the downstream target of hnRNPA2B1 by m⁶A site. Moreover, hnRNPA2B1 enhanced the mRNA stability of LDHA through m⁶A-dependent manner. LDHA inhibitor (FX-11) could reverse the effect of hnRNPA2B1. Taken together, the data revealed that hnRNPA2B1 promoted the proliferation, migration and aerobic glycolysis of cervical cancer cells by m⁶A/LDHA-dependent manner. These findings might bring a new idea for cervical cancer treatment.

This study investigated Cerium oxide nanoparticles (CeONPs) effect on central neuropathic pain (CNP). The compressive method of spinal cord injury (SCI) model was used for pain induction. Three groups were formed by a random allocation of 24 rats. In the treatment group, CeONPs were injected above and below the lesion site immediately after inducing SCI. pain symptoms were evaluated using acetone, Radian Heat, and Von Frey tests weekly for six weeks. Finally, we counted fibroblasts using H&E staining. We evaluated the expression of Cx43, GAD65 and HDAC2 proteins using the western blot method. The analysis of results was done by PRISM software. At the end of the study, we found that CeONPs reduced pain symptoms to levels similar to those observed in normal animals. CeONPs also increased the expression of GAD65 and Cx43 proteins but did not affect HDAC2 inhibition. CeONPs probably have a pain-relieving effect on chronic pain by potentially preserving GAD65 and Cx43 protein expression and hindering fibroblast infiltration.

Rheumatoid arthritis (RA) is a chronic condition characterized by inflammation and an abnormal immune response. N6-methyladenosine (m6A) methylation has altered nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing (NLRP) 3. This change is implicated in the regulation of cell pyroptosis and inflammation. WTAP has a crucial role in regulating NLRP3 m6A. In this work, we used a rat model of collagen-induced arthritis (CIA) to investigate the involvement of WTAP in the evolution of inflammation in RA. The purpose of silencing or overexpressing WTAP in RA-fibroblast-like synoviocytes (RA-FLSs) treated with TNF-α was to identify its impact on pyroptosis, NLRP3 inflammasome-related proteins, the secretion of pro-inflammatory cytokines and migration. Bioinformatics techniques were used to pinpoint the exact target controlled by WTAP. To assess WTAP and NLRP3's role in RA-FLSs, we used methylated RNA immunoprecipitation, LDH test, flow cytometry, RT-qPCR, Western blotting, and Transwell. Our results show that WTAP expression is upregulated in both RA rats and cell models. Cell pyroptosis, NLRP3-related pro-inflammatory cytokines, and migration were reduced in TNF-α-treated RA-FLSs when WTAP was knocked down, whereas overexpression of WTAP displayed the opposite effect in RA-FLSs. WTAP mediated m6A modification in the NLRP3 mRNA and enhanced its mRNA stability. These results suggested that WTAP promoted FLSs pyroptosis and related inflammatory response via NLRP3 and identified WTAP as a potential target for treating RA.

Diabetic nephropathy (DN) is one of microvascular complication associated with diabetes. Circular RNAs (circRNAs) have been shown to be involved in DN pathogenesis. Hence, this work aimed to explore the role and mechanism of circ_Arf3 in DN. Mouse mesangial cells (MCs) cultured in high glucose (HG) condition were used for functional analysis. Cell proliferation was determined using 5-ethynyl-2'-deoxyuridine (EdU) and cell counting kit-8 assays. Western blotting was used to measure the levels of proliferation indicator PCNA and fibrosis-related proteins α-smooth muscle actin (α-SMA), collagen I (Col I), fibronectin (FN), and collagen IV (Col IV). The binding interaction between miR-107-3p and circ_Arf3 or Tmbim6 (transmembrane BAX inhibitor motif containing 6) was confirmed using dual-luciferase reporter and pull-down assays. Circ_Arf3 is a stable circRNA, and the expression of circ_Arf3 was decreased after HG treatment in MCs. Functionally, ectopic overexpression of circ_Arf3 protected against HG-induced proliferation and elevation of fibrosis-related proteins in MCs. Mechanistically, circ_Arf3 directly bound to miR-107-3p, and Tmbim6 was a target of miR-107-3p. Further rescue assay showed miR-107-3p reversed the protective action of circ_Arf3 on MCs function under HG condition. Moreover, inhibition of miR-107-3p suppressed HG-induced proliferation and fibrosis, which were attenuated by Tmbim6 knockdown in MCs. CircRNA Arf3 could suppress HG-evoked mesangial cell proliferation and fibrosis via miR-107-3p/Tmbim6 axis, indicating the potential involvement of this axis in DN progression.

Previous studies have suggested that N6-methyladenosine (mA) modification of RNA affects fundamental aspects of RNA metabolism, and mA dysregulation is implicated in various human diseases, including Alzheimer's disease (AD). This study is designed to explore the role and mechanism of methyltransferase-like 14 (METTL14) in the pathogenesis of AD. SK-N-SH cells were treated with Aβ1-42 to establish an in vitro model of AD. Cerebellin 4 (CBLN4) and METTL14 expression levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability and apoptosis were analyzed using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry assay. B-cell lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax), C-caspase-3, total-caspase-3, C/EBP homologous protein (CHOP), and glucose-related protein 78 (GRP78) protein levels were determined using Western blot. Interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) levels were analyzed using ELISA. Reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) products were examined using special assay kits. Interaction between CBLN4 and METTL14 was verified using methylated RNA immunoprecipitation (MeRIP) and dual-luciferase reporter assays. CBLN4 and METTL14 expression was decreased in Aβ1-42-treated SK-N-SH cells. Upregulation of CBLN4 relieved Aβ1-42-induced SK-N-SH cell apoptosis, inflammation, oxidative stress, and endoplasmic reticulum (ER) stress in vitro. At the molecular level, METTL14 could improve the stability and expression of CBLN4 mRNA via m6A methylation. Our findings indicated that m6A methylase METTL14-mediated upregulation of CBLN4 mRNA stability could repress Aβ1-42-triggered SK-N-SH cell injury, providing a promising therapeutic target for AD treatment.

Natural products are a great resource for physiologically active substances. It is widely recognized that a major percentage of current medications are derived from natural compounds or their synthetic analogues. Triterpenoids are widespread in nature and can prevent cancer formation and progression. Despite considerable interest in these triterpenoids, their interactions with lipid bilayers still need to be thoroughly investigated. The aim of this study is to examine the interactions of lupeol, a pentacyclic triterpenoid, with model membranes composed of 1,2‑dipalmitoyl‑sn‑glycerol‑3‑phosphocholine (DPPC) by using non-invasive techniques such as differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The DSC study demonstrated that the incorporation of lupeol into DPPC membranes shifts the L_β'-to-P_β' and P_β'-to-L_α phase transitions toward lower values, and a loss of main phase transition cooperativity is observed. The FTIR spectra indicated that the increasing concentration (10 mol%) of lupeol causes an increase in the molecular packing and membrane fluidity. In addition, it is found that lupeol's OH group preferentially interacts with the head group region of the DPPC lipid bilayer. These findings provide detailed information on the effect of lupeol on the DPPC head group and the conformation and dynamics of the hydrophobic chains. In conclusion, the effect of lupeol on the structural features of the DPPC membrane, specifically phase transition and lipid packing, has implications for understanding its biological function and its applications in biotechnology and medicine.

Dexmedetomidine (DEX) has been confirmed to exert neuroprotective effects in various nerve injury models by regulating ferroptosis, including spinal cord injury (SCI). Although it has been established that CDGSH iron sulfur domain 2 (CISD2) can regulate ferroptosis, whether DEX can regulate ferroptosis by CISD2 in SCI remains unclear. Lidocaine was used to induce PC12 cells and stimulate rats to establish SCI models in vitro and in vivo. MTT assays were performed to analyze cell viability. Ferroptosis was assessed by determining the levels of cellular reactive axygen species (ROS), malondialdehyde (MDA), glutathione (GSH), and Fe²⁺. Ferritinophagy was analyzed by LysoTracker staining, FerroOrange staining, and immunofluorescence. Western blotting was carried out to quantify the levels of several proteins. Fluorescence microscopy was also used to observe cell autophagy. The morphology of mitochondria within the tissue was observed under transmission electron microscopy (TEM). DEX treatment weakened lidocaine-induced elevation of ROS, Fe²⁺, and MDA and reduced GSH in PC12 cells, indicating that DEX treatment weakened lidocaine-induced ferroptosis in PC12 cells. Similarly, lidocaine promoted autophagy, Fe²⁺, and microtubule-associated protein 1 light chain 3 (LC3) in PC12 cells and suppressed ferritin and p62 protein levels, indicating that DEX could weaken lidocaine-induced ferritinophagy in PC12 cells. DEX treatment improved the BBB score, reduced tissue damage, increased the number of neurons, and alleviated mitochondrial damage by inhibiting ferroptosis and ferritinophagy in lidocaine-induced SCI rat models. The decreased CISD2, ferritin heavy chain 1 (FTH1), solute carrier family 7-member 11-glutathione (SLC7A11), and glutathione peroxidase 4 (GPX4) protein levels and the elevated nuclear receptor coactivator 4 (NCOA4) protein levels in rat models in the lidocaine group were weakened by DEX treatment. Moreover, CISD2 inhibition reversed the inhibitory effects of DEX treatment on lidocaine-induced ferroptosis and ferritinophagy in PC12 cells significantly. Taken together, DEX treatment could impair lidocaine-induced SCI by inhibiting ferroptosis and ferritinophagy by upregulating CISD2 in rat models.

The current study explored melatonin (MEL) and its receptors, including MEL type 1 receptor (MT1) receptor and MEL type 2 receptor (MT2), along with the angiotensin-converting enzyme 2 (ACE₂), influence on vascular responses to angiotensin II (Ang II) in rat aortic segments of normal and diabetic rats. The isolated aortic segments were exposed to MEL, the MEL agonist; ramelteon (RAM), the MEL antagonist; luzindole (LUZ), and an ACE₂ inhibitor (S, S)-2-(1-Carboxy-2-(3-(3,5-dichlorobenzyl)-3 H-imidazol-4-yl)-ethylamino)-4-methylpentanoic acid,) on Ang II-induced contractions in non-diabetic normal endothelium (non-DM E+), non-diabetic removed endothelium (non-DM E-), and streptozotocin-induced diabetic endothelium-intact (STZ-induced DM E+) rat aortic segments, as well as their combination in STZ-induced DM E + segments, were also included. The current results showed that MEL and RAM shifted Ang II dose-response curve (DRC) to the right side in non-DM E + and non-DM E- aorta but not in STZ-induced DM E + aorta. However, ACE₂ inhibition abolished Ang II degradation only in STZ-induced DM E + segments, not in non-DM E + segments. Additionally, the combinations of MEL-LUZ and RAM-ACE₂ inhibitor caused a rightward shift in Ang II response in STZ-induced DM E + segments, while the MEL-LUZ combination decreased Ang II DRC. The findings suggest that the effects of MEL and ACE₂ inhibitor on Ang II responses depend on the condition of the endothelium and the distribution of the MEL receptors.