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Biochimica Et Biophysica Acta.... Jul 2024Ginsenoside Rh2 (Rh2) is a ginseng saponin comprising a triterpene core and one unit of glucose and has attracted much attention due to its diverse biological...
Ginsenoside Rh2 (Rh2) is a ginseng saponin comprising a triterpene core and one unit of glucose and has attracted much attention due to its diverse biological activities. In the present study, we used small-angle X-ray diffraction, solid-state NMR, fluorescence microscopy, and MD simulations to investigate the molecular interaction of Rh2 with membrane lipids in the liquid-disordered (Ld) phase mainly composed of palmitoyloleoylphosphatidylcholine compared with those in liquid-ordered (Lo) phase mainly composed of sphingomyelin and cholesterol. The electron density profiles determined by X-ray diffraction patterns indicated that Rh2 tends to be present in the shallow interior of the bilayer in the Ld phase, while Rh2 accumulation was significantly smaller in the Lo phase. Order parameters at intermediate depths in the bilayer leaflet obtained from H NMR spectra and MD simulations indicated that Rh2 reduces the order of the acyl chains of lipids in the Ld phase. The dihydroxy group and glucose moiety at both ends of the hydrophobic triterpene core of Rh2 cause tilting of the molecular axis relative to the membrane normal, which may enhance membrane permeability by loosening the packing of lipid acyl chains. These features of Rh2 are distinct from steroidal saponins such as digitonin and dioscin, which exert strong membrane-disrupting activity.
PubMed: 38960300
DOI: 10.1016/j.bbamem.2024.184366 -
Cellular Signalling Jul 2024To investigate whether tricyclic decylbenzoxazole (TDB) regulates liver cancer cell proliferation and apoptosis through p300-mediated FOXO acetylation.
OBJECTIVE
To investigate whether tricyclic decylbenzoxazole (TDB) regulates liver cancer cell proliferation and apoptosis through p300-mediated FOXO acetylation.
METHODS
Sequencing, adenovirus, and lentivirus transfection were performed in human liver cancer cell line SMMC-7721 and apoptosis was detected by Tunel, Hoechst, and flow cytometry. TEM for mitochondrial morphology, MTT for cell proliferation ability, Western blot, and PCR were used to detect protein levels and mRNA changes.
RESULTS
Sequencing analysis and cell experiments confirmed that TDB can promote the up-regulation of FOXO3 expression. TDB induced FOXO3 up-regulation in a dose-dependent manner, promoted the expression of p300 and Bim, and enhanced the acetylation and dephosphorylation of FOXO3, thus promoting apoptosis. p300 promotes apoptosis of cancer cells through Bim and other proteins, while HAT enhances the phosphorylation of FOXO3 and inhibits apoptosis. Overexpression of FOXO3 can increase the expression of exo-apoptotic pathways (FasL, TRAIL), endo-apoptotic pathways (Bim), and acetylation at the protein level and inhibit cell proliferation and apoptotic ability, while FOXO3 silencing or p300 mutation can partially reverse apoptosis. In tumor tissues with overexpression of FOXO3, TDB intervention can further increase the expression of p53 and caspase-9 proteins in tumor cells, resulting in loss of mitochondrial membrane integrity during apoptosis, the release of cytoplasm during signal transduction, activation of caspase-9 and synergistic inhibition of growth.
CONCLUSION
TDB induces proliferation inhibition and promotes apoptosis of SMMC-7721 cells by activating p300-mediated FOXO3 acetylation.
PubMed: 38960058
DOI: 10.1016/j.cellsig.2024.111280 -
The Journal of Biological Chemistry Jul 2024The human ether-g-go-go-related gene (hERG) encodes the Kv11.1 (or hERG) channel that conducts the rapidly activating delayed rectifier potassium current (I). Naturally...
The human ether-g-go-go-related gene (hERG) encodes the Kv11.1 (or hERG) channel that conducts the rapidly activating delayed rectifier potassium current (I). Naturally occurring mutations in hERG impair the channel function and cause long QT syndrome type 2 (LQT2). Many missense hERG mutations lead to a lack of channel expression on the cell surface, representing a major mechanism for the loss-of-function of mutant channels. While it is generally thought that a trafficking defect underlies the lack of channel expression on the cell surface, in the present study, we demonstrate that the trafficking defective mutant hERG G601S can reach the plasma membrane but is unstable and quickly degrades, which is akin to Wild Type (WT) hERG channels under low K conditions. We previously showed that Serine (S) residue at 624 in the innermost position of the selectivity filter of hERG is involved in hERG membrane stability such that substitution of Serine 624 with Threonine (S624T) enhances hERG stability and renders hERG insensitive to low K culture. Here, we report that the intragenic addition of S624T substitution to trafficking defective hERG mutants G601S, N470D and P596R led to a complete rescue of the function of these otherwise loss-of-function mutant channels to a level similar to the WT channel, representing the most effective rescue means for the function of mutant hERG channels. These findings not only provide novel insights into hERG mutation-mediated channel dysfunction, but also point to the critical role of S624 in hERG stability on the plasma membrane.
PubMed: 38960041
DOI: 10.1016/j.jbc.2024.107526 -
New Biotechnology Jul 2024Process intensification is crucial for industrial implementation of biocatalysis and can be achieved by continuous process operation in miniaturized reactors with...
Process intensification is crucial for industrial implementation of biocatalysis and can be achieved by continuous process operation in miniaturized reactors with efficiently immobilized biocatalysts, enabling their long-term use. Due to their extremely large surface-to-volume ratio, nanomaterials are promising supports for enzyme immobilization. In this work, different functionalized nanofibrous nonwoven membranes were embedded in a two-plate microreactor to enable immobilization of hexahistidine (His)-tagged amine transaminases (ATAs) in flow. A membrane coated with Cu ions gave the best results regarding His-tagged ATAs immobilization among the membranes tested yielding an immobilization yield of up to 95.3 % for the purified N-His-ATA-wt enzyme. Moreover, an efficient one-step enzyme immobilization process from overproduced enzyme in Escherichia coli cell lysate was developed and yielded enzyme loads up to 1088 U mL. High enzyme loads resulted in up to 80 % yields of acetophenone produced from 40 mM (S)-α-methylbenzylamine in less than 4 min using a continuously operated microreactor. Up to 81 % of the initial activity was maintained in a 5-day continuous microreactor operation with immobilized His-tagged ATA constructs. The highest turnover number within the indicated time was 7.23·10, which indicates that this immobilization approach using advanced material and reactor system is highly relevant for industrial implementation.
PubMed: 38960020
DOI: 10.1016/j.nbt.2024.06.005 -
Steroids Jul 2024Breast cancer stands as a leading contributor to global cancer-related mortality. Progressing Research and Medical Innovations Elevate Treatment Choices and Results for...
BACKGROUND
Breast cancer stands as a leading contributor to global cancer-related mortality. Progressing Research and Medical Innovations Elevate Treatment Choices and Results for Breast Cancer. Among these, Peimine, a natural steroid inherent in plants, notably within the Fritillaria species, demonstrates the capability to trigger apoptosis in breast cancer cells through the mitochondrial membrane permeation pathway. Nevertheless, its impact within an appropriate cancer model remains an area necessitating further exploration.
AIM
This study explored the in vivo anticancer effects of peimine on MRMT-1 Cell-line induced breast cancer in rats.
METHOD
Cancer was induced by the administration of MRMT-1 (6 x 10 cells) cells in the mammary pads of SD rats. The daily drug treatmentcommenced on day 14 and continued till 39 days. Peimine was administered in two doses (0.24 mg/kg and 0.48 mg/kg p.o) to examine its efficacy in curing breast cancer while tamoxifen was used as standard.
RESULTS
A reduction in tumour size was observed in the peimine-treated groups. Peimine can correct the changed blood cell count in addition to its anti-tumour activity. In peimine-treated rats, imbalanced immune marker IgE, serum oxidative marker, and tissue apoptotic markers like cytochrome c and calcium level were shown to be restored significantly.
CONCLUSION
Our findings imply that quinine has beneficial effects as an anti-neoplastic medication for breast cancer, most likely through its apoptotic activity. More research is necessary to thoroughly understand their mechanisms of action, ideal dose, and potential side effects.
PubMed: 38959994
DOI: 10.1016/j.steroids.2024.109467 -
Dermatology Online Journal Apr 2024Squamoid eccrine ductal carcinoma (SEDC) is a cutaneous adnexal malignancy that is histologically challenging to distinguish from squamous cell carcinoma. We report... (Review)
Review
Squamoid eccrine ductal carcinoma (SEDC) is a cutaneous adnexal malignancy that is histologically challenging to distinguish from squamous cell carcinoma. We report three cases of this rare entity and review the present literature regarding clinical, histological, and immunohistochemical features. Patients presented with a single nodule or plaque lesion on their back and temple. The shave biopsies for Patient A and C were interpreted as SEDC. Patient B's initial shave biopsy was interpreted as probable surface of squamous cell carcinoma, and subsequent excision revealed SEDC. Ductal differentiation was confirmed by positive expression of epithelial membrane antigen and carcinoembryonic antigen immunostains in all three patients. Review of the 67 previously reported cases emphasizes the importance of diagnosing SEDC accurately and promptly given its potential for distant metastasis and mortality. Perineural or lymphatic invasion is associated with higher rate of recurrence or metastasis. There should be high pathologic suspicion for SEDC in an elderly patient presenting with a palpable lesion, even if located outside of the head and neck area, particularly when there is suggestion of ductal differentiation in a sample of a squamous neoplasm.
Topics: Humans; Male; Carcinoma, Squamous Cell; Sweat Gland Neoplasms; Aged; Female; Eccrine Glands; Carcinoma, Ductal; Aged, 80 and over; Immunohistochemistry; Skin Neoplasms; Carcinoembryonic Antigen; Diagnosis, Differential; Mucin-1; Middle Aged
PubMed: 38959917
DOI: 10.5070/D330263577 -
EBioMedicine Jul 2024The clinical heterogeneity of myasthenia gravis (MG), an autoimmune disease defined by antibodies (Ab) directed against the postsynaptic membrane, constitutes a...
BACKGROUND
The clinical heterogeneity of myasthenia gravis (MG), an autoimmune disease defined by antibodies (Ab) directed against the postsynaptic membrane, constitutes a challenge for patient stratification and treatment decision making. Novel strategies are needed to classify patients based on their biological phenotypes aiming to improve patient selection and treatment outcomes.
METHODS
For this purpose, we assessed the serum proteome of a cohort of 140 patients with anti-acetylcholine receptor-Ab-positive MG and utilised consensus clustering as an unsupervised tool to assign patients to biological profiles. For in-depth analysis, we used immunogenomic sequencing to study the B cell repertoire of a subgroup of patients and an in vitro assay using primary human muscle cells to interrogate serum-induced complement formation.
FINDINGS
This strategy identified four distinct patient phenotypes based on their proteomic patterns in their serum. Notably, one patient phenotype, here named PS3, was characterised by high disease severity and complement activation as defining features. Assessing a subgroup of patients, hyperexpanded antibody clones were present in the B cell repertoire of the PS3 group and effectively activated complement as compared to other patients. In line with their disease phenotype, PS3 patients were more likely to benefit from complement-inhibiting therapies. These findings were validated in a prospective cohort of 18 patients using a cell-based assay.
INTERPRETATION
Collectively, this study suggests proteomics-based clustering as a gateway to assign patients to a biological signature likely to benefit from complement inhibition and provides a stratification strategy for clinical practice.
FUNDING
CN and CBS were supported by the Forschungskommission of the Medical Faculty of the Heinrich Heine University Düsseldorf. CN was supported by the Else Kröner-Fresenius-Stiftung (EKEA.38). CBS was supported by the Deutsche Forschungsgemeinschaft (DFG-German Research Foundation) with a Walter Benjamin fellowship (project 539363086). The project was supported by the Ministry of Culture and Science of North Rhine-Westphalia (MODS, "Profilbildung 2020" [grant no. PROFILNRW-2020-107-A]).
PubMed: 38959848
DOI: 10.1016/j.ebiom.2024.105231 -
Theriogenology Jun 2024Cryopreservation is a pivotal technique in safeguarding genetic material across diverse species, despite its inherent challenges linked to induced spermatozoa damage,...
Cryopreservation is a pivotal technique in safeguarding genetic material across diverse species, despite its inherent challenges linked to induced spermatozoa damage, notably apoptosis and lipid peroxidation (LPO). Given the insufficient antioxidant defense of spermatozoa against LPO, there is a rising interest in integrating additional additives into extenders to ameliorate mammalian semen quality. Among these additives, flavonoids have garnered considerable attention due to their potent antioxidative properties. Hence, our study aimed to assess the efficacy of flavone (FL) and 3-hydroxyflavone (3-OH = ) supplementation in the cryopreservation medium to protect canine sperm against the damaging impacts of freezing and ensure the preservation of their reproductive potential. Semen was collected from five Beagle stud dogs and then pooled. Then, the sample was divided into 7 groups, each treated with 1) 0 mM, 2) 0.1 mM FL, 3) 0.2 mM FL, 4) 0.4 mM FL, 5) 0.1 mM 3-OH = , 6) 0.2 mM 3-OH = , 7) 0.4 mM 3-OH = . Semen samples were subjected to cryopreservation in French straws and glycerol as a cryoprotectant. In the frozen thawed semen, sperm motility parameters by CASA system and sperm membrane integrity, acrosome status, mitochondrial activity, DNA fragmentation, early apoptosis with capacitation, and LPO were assessed using flow cytometry just after thawing (0 h) and 4 h post thaw. Results reveal significant increase in the proportion of live spermatozoa with undamaged acrosomes in the FL 0.1 and 3-OH = 0.2 groups at 0 h post thaw. At this time point, 3-OH = 0.1 significantly reduced the DNA fragmentation index (DFI) compared to the FL 0.1 and 0.2 groups. However, after the next 4 h, 3-OH = 0.4 exhibited the lowest (P < 0.05) DFI compared to FL 0.2 and 3-OH = 0.1. Additionally, 3-OH = 0.4 showed the highest (P < 0.05) proportion of non apoptotic and non capacitated spermatozoa compared to FL 0.1 0 h post-thaw. Simultaneously, the same group demonstrated significant reduction in apoptotic and capacitated sperm cells, at 0 h and 4 h post-thaw. Moreover, 3-OH = at 0.1 (0 h and 4 h) and 0.2 mM (4 h) significantly enhances the proportion of live sperm without LPO post thaw. Whitin the FL groups, only 0.4 FL significantly increased the percentage of live sperm without LPO. No significant effect of the tested substances was observed on sperm motility, cell membrane integrity, or mitochondrial activity. These findings highlight the promising role of flavone and 3-hydroxyflavone in enhancing sperm resilience during cryopreservation, suggesting their protective function against acrosome damages, capacitation, apoptosis and lipid peroxidation.
PubMed: 38959842
DOI: 10.1016/j.theriogenology.2024.06.025 -
Food Chemistry Jun 2024Improving the freezing resistance of yeast in dough starters is one of the most effective methods to promote the healthy development of frozen dough technology. When the...
Improving the freezing resistance of yeast in dough starters is one of the most effective methods to promote the healthy development of frozen dough technology. When the dough starter was composed of yeast, lactic acid bacteria and acetic acid bacteria, the microbial proportion was 10:1:5, and the ratio of wheat flour to corn flour was 1:1. The proline contents of the starters and the survival rates and fermentation capacity of yeast significantly increased compared with those of the starter composed of yeast and wheat flour only (P < 0.05). Laser confocal microscopy observation showed that the cell membrane damage of yeast obviously decreased. Low-field nuclear magnetic resonance method revealed that the water distribution state of starters changed. Adding corn flour and acetic acid bacteria to dough starter in appropriate proportions improves yeast freezing resistance.
PubMed: 38959800
DOI: 10.1016/j.foodchem.2024.140258 -
Food Chemistry Jun 2024In this study, we evaluated the potential for exogenous thymol to slow this decline by measuring the effects of thymol application on cell wall, energy, and membrane...
In this study, we evaluated the potential for exogenous thymol to slow this decline by measuring the effects of thymol application on cell wall, energy, and membrane lipid metabolism. The results showed that thymol application improved the preservation of the total soluble solids, titratable acidity, decay rate, and anthocyanin content, and effectively inhibited the accumulation of O, HO, and malondialdehyde in blueberries during storage. Thymol application also effectively maintained fruit firmness, cell wall structure, and energy levels, while delaying the degradation of membrane phospholipids and unsaturated fatty acids during the storage of post-harvest blueberries. Therefore, exogenous thymol can maintain the quality of blueberry fruits by regulating energy and membrane lipid metabolism and reducing cell wall degradation. Thus, thymol-treatment could be a suitable biocontrol agent for maintaining blueberry quality and extending blueberry fruit storage life.
PubMed: 38959798
DOI: 10.1016/j.foodchem.2024.140193