Journal of Bioenergetics and Biomembranes最新文献

The KunMingShanHaiTang Formula (KMSHTF), adjusted by Professor Zhong Chuanhua for the treatment of ulcerative colitis (UC), is the work of a renowned veteran practitioner of Chinese medicine. However, its specific mechanism remains unknown. Consequently, it is intriguing to investigate the molecular mechanism by which KMSHTF treats UC. To elucidate the mechanism of KMSHTF in the treatment of UC in rats. Initially, the active ingredients and key target genes of KMSHTF in treating UC were analyzed using network pharmacology. Protein-Protein interaction and gene enrichment analyses were performed to predict key targets and pathways. Subsequently, UC rats were treated with KMSHTF, and the expression proteins in intestinal tissue were detected. Finally, the active compounds of KMSHTF intreating ulcerative colitis were further screened using Molecular Docking, and their pharmacological effects were validated through cell experiments. A total of 47 active compounds and 365 key target genes of KMSHTF for UC treatment were identified through the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,along with the GeneCards database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment Analysis revealed that KMSHTF exerted its therapeutic effects on UC through regulating multiple pathways. In this study, the HIF-1α pathway was selected as the main molecular pathway of KMSHTF treating UC, and further validation was conducted through in vivo and in vitro experiments.Animal studies revealed that KMSHTF significantly ameliorated UC symptoms in rats, including diarrhea,rectal bleeding and specific pathological alterations in the intestinal wall. Furthermore, KMSHTF reduced pro-inflammatory cytokines IL-6 and TNF-α, up-regulated IL-4 of M2 macrophages and down-regulated iNOS and IL-1β of M1 macrophages. Additionally, it decreased the expression levels of HKII and GLUT1 related HIF-1α pathway. The three active compounds of KMSHTF, Baicalein, Palmatine and Triptonide-were selected based on their strong binding affinity with HIF-1α and HKII through computational molecular docking. Cellular experiments demonstrated that each of these compounds downregulated the protein expression levels of HIF-1α, HKII, GLUT1 and IL-6 in an intestinal wall cell model. Of Note, Baicalein exhibited the most pronounced effect. However, the overexpression of HIF-1α reversed the Baicalein-induced downregulation of HKII, GLUT1 and IL-6 at the protein level in vitro. KMSHTF may modulate macrophage metabolism to promote M2 polarization through the HIF-1α pathway, thereby contributing to its therapeutic efficacy in ulcerative colitis (UC). Baicalein, Palmatine, and Triptonide are the three core active compounds of KMSHTF that primarily contribute to this hypothesis.

Ulcerative colitis (UC) is a common chronic relapsing inflammatory disease that threatens human life. This study aims to explore the mechanism of LncRNA CBR3-AS1 in pyroptosis of intestinal epithelial cells in UC. The levels of CBR3-AS1, KLF2, and SUGT1 in UC cells were detected. After downregulating CBR3-AS1 expression, cell viability and pyroptosis were measured, followed by the detection of SOD and MDA levels. The binding of CBR3-AS1 to EZH2, enrichment of EZH2 and H3K27me3 on the KLF2 promoter, and binding of KLF2 to the SUGT1 promoter were assayed. The role of CBR3-AS1 in pyroptosis was validated in animal models. We found that CBR3-AS1 and SUGT1 were increased in UC cells, and KLF2 was decreased. After downregulation of CBR3-AS1, cell viability was increased and pyroptosis was alleviated. CBR3-AS1 recruited EZH2 to occupy the KLF2 promoter, leading to increased H3K27me3 levels and suppressed KLF2 expression, reducing the enrichment of KLF2 on the SUGT1 promoter, finally promoting SUGT1 expression. SUGT1 overexpression or KLF2 downregulation alleviated the protective effect of silencing CBR3-AS1 on pyroptosis in UC cells. CBR3-AS1 downregulation alleviates cell pyroptosis in colonic tissues. In conclusion, CBR3-AS1 exacerbated pyroptosis of intestinal epithelial cells in UC via the KLF2/SUGT1 pathway.

Fibrillation of the amyloid beta (Aβ) peptide has often been associated with neurodegenerative pathologies such as Alzheimer's disease. In this study we examined the influence of several potential compositions of the lipid membrane on Aβ fibrillation by using liposomes as a basic model membrane. Firstly, it was revealed that Aβ fibrillation kinetics were enhanced and had the potential to occur at a faster rate on more fluid membranes compared to solid membranes. Next, the extent of fibril-related damage to membranes was examined with analysis of membrane polarity via the steady-state emission spectra of 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan). It was revealed that there was slight hydration behavior of the membrane during the lag phase (t_lag) of the kinetic process, possibly coinciding with Aβ monomer binding. However, as the fibrillation kinetic process continued the membrane gradually dehydrated. Hydration states of membranes during and after Aβ fibrillation processes were further examined via deconvolution analysis of the obtained Laurdan spectra. This allows a mapping of membrane hydration from the interior to exterior regions of the lipid membrane. Results revealed slight but definitive variations in deeper region membrane polarity during the time course of Aβ fibrillation, suggesting Aβ aggregation impacts not only the surface level aggregating region but also the inner regions of the membrane. These results can ultimately contribute to the future investigations of the nature of the membrane damage caused by Aβ aggregation.

The main therapeutic strategy for the treatment of patients with toxic liver failure is the elimination of the toxic agent in combination with the targeted mitigation of pathological processes that have been initiated due to the toxicant. In the current research we evaluated the strategy of metabolic supplementation to improve mitochondrial bioenergetics during acute liver intoxication. In our study, we have shown that acute CCl₄-induced intoxication negatively affects Complex I (in the presence of glutamate-malate as energy substrates) based respiration, generation of mitochondrial membrane potential (ΔΨ_m), mitochondrial NAD(P)H pool and NADH redox index, mitochondrial calcium retention capacity (CRC) and structure and functions of the liver. Boosting of mitochondrial bioenergetics through the complex II, using succinate as metabolic substrate in vitro, significantly improved mitochondrial respiration and generation of ΔΨ_m, but not mitochondrial CRC. Co-application of rotenone along with succinate, to prevent possible reverse electron flow, didn't show significant differences compared to the effects of succinate alone. Treatment of animals with acute liver failure, using a metabolic supplement containing succinate, inosine, methionine and nicotinamide improved Complex I based respiration, generation of ΔΨ_m, mitochondrial NAD(P)H pool and NADH redox index, mitochondrial CRC and slightly decreased the level of oxidative stress. These changes resulted in averting destructive and dystrophic changes in the structure of rat liver tissue caused by CCl₄ intoxication, concomitantly enhancing hepatic functionality. Thus, we propose that metabolic supplementation targeting complex II could serve as a potential adjunctive therapy in the management of acute liver intoxication.

To investigate the role of silent information regulator 6 (SIRT6) in regulating podocyte injury in diabetic nephropathy (DN) through autophagy mediated by Notch signaling pathway. A blank control group (group A), a diabetic nephropathy group (group B), and a Sirt6 intervention group (group C) were established. The group A cells were human normal glomerular podocyte cell lines (HGPCs) without any treatment. In group B, the cells were cultivated in glucose medium containing 30 mmol/L and a 10 µmol/L anti-LSirt6 antibody solution. Three sets of cells were tested for their capacity to proliferate via CCK8, for protein expression via Western blot, for associated mRNA expression levels via qPCR, and for cell migration and invasion ability via Transwell. The podocyte proliferation and migration activity in group B were reduced compared to group A, while these properties in group C were elevated compared to group B (DN). B Group is diabetes nephropathy. Compared with those in group B, the number of invading podocytes in group C were greater than those in group A, and the overall apoptosis rate in group C was lower than that in group B. The expression levels of apoptotic proteins in the podocytes in group C were greater than those in group B, and the bcl-2 level was lower than those in group B. The Notch1 and Jagged1 mRNA and protein levels in the podocytes in group B were greater than those in group A, whereas those in the podocytes in group C were lower than those in group B. Sirt6 can protect against podocyte autophagy injury in DN by regulating the Notch1 signaling pathway.

Cholestasis caused by impaired bile secretion in the liver is associated with the accumulation of primary bile acids (BA): cholic acid (CA) and chenodeoxycholic acid (CDCA) in the cells of this organ. The paper studies the uncoupling effect of the CA and CDCA on the succinate-fueled rat liver mitochondria under conditions of ΔpH to Δψ conversion by nigericin. It has been established that without nigericin, the dependence of the resting-state (state 4) respiration rate on the concentrations of these BA is nonlinear and is described by a parabolic equation. Under these conditions, the specific inhibitor of the ADP/ATP-antiporter - carboxyatractylate and the substrate of the aspartate/glutamate-antiporter - glutamate do not affect the state 4 respiration of mitochondria stimulated by these BA. It is suggested that without nigericin, the protonophore action of BA is due to the formation of a dimeric complex of their anion with the acid. In the presence of nigericin, the dependence of state 4 respiration rate on BA concentration is linear. Under these conditions, carboxyatractylate inhibits BA-stimulated respiration. Unlike the CDCA, the uncoupling action of CA is also suppressed by the substrates of the aspartate/glutamate-antiporter. The obtained results are considered as evidence that in the presence of nigericin, uncoupling action of CDCA is carried out primarily with the participation of ADP/ATP-antiporter. Both ADP/ATP-antiporter and aspartate/glutamate-antiporter are involved in the uncoupling action of CA. It is concluded that nigericin modifies the mechanism of the uncoupling action of BA in liver mitochondria by converting ΔpH to Δψ.

Lithium is used in the long-term treatment of bipolar disorder, exhibiting a beneficial effect on the neuronal cells. The concentration of lithium in the blood serum can vary and can easily approach a level that is related to cardiotoxic adverse effects. This is due to its narrow therapeutic index. In this study, we investigated the effect of higher than therapeutic dose of lithium. Rat cardiomyoblast cells were treated with 2 mM LiCl for 48 h, after which the mitochondrial parameters of the cells were analyzed. Lithium exposure reduced maximal respiratory capacity by diminishing reserve respiratory capacity (RRC), linked to a decrease in complex I (NADH dehydrogenase) activity and elevated superoxide radical levels. In addition, lithium treatment altered the composition of cellular membranes, including mitochondrial cardiolipin, a lipid essential for mitochondrial function. These findings suggest that impaired complex I activity, oxidative stress, and cardiolipin depletion collectively impair the ability of cells to meet high energy demands.

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.

Oxidative stress-induced lens epithelial cells (LECs) death plays a pivotal role in pathogenesis of age-related cataract (ARC), causing significant visual impairment. Apoptosis of porcine granulosa cells mediated by MMP2 is linked to DNA damage. The current study aimed to investigate the potential mechanism of MMP2 in DNA damage, apoptosis and senescence of lens epithelial cells caused by oxidative stress. HLE-B3 cells were treated with different doses of H₂O₂ for 24 h, and CCK-8 was used to detect cell viability. Furthermore, western blotting was used to detect the expressions of MMP2, Bcl2, Bax, cleaved caspase3, γ-H2AX, p16, p21, and TIMP2. DCFH-DA staining was used to assess ROS levels. Moreover, EdU staining was used to detect cell proliferation, and flow cytometry was used to detect cell apoptosis. Then, 15A3 immunofluorescence staining and γ-H2AX staining were used to detect DNA damage. In addition, SA-β-gal staining was used to observe cell senescence. The present findings suggest that oxidative stress triggers damage to LECs viability and elevates the expression of MMP2. Furthermore, MMP2 interference attenuates H₂O₂-induced active damage, apoptosis, DNA damage, and cellular senescence in LECs. Additionally, TIMP2 expression is down-regulated in H₂O₂-induced LECs, which suppresses the expression of MMP2 induced by H₂O₂. These findings highlight the crucial role of MMP2 and TIMP2 in the modulation of oxidative stress-induced cellular responses in LECs. Collectively, TIMP2 alleviates H₂O₂-induced lens epithelial cell viability damage, apoptosis, DNA damage and cell senescence in LECs by inhibiting MMP2.