Cell Biochemistry and Biophysics最新文献

Neurodegenerative disorders are associated with the accumulation of disease-related proteins intracellularly and extracellularly. Extracellular chaperones play a crucial role in clearing the extracellularly accumulated proteins. In this study, we observed the extracellular chaperone-like potential of BSA at physiological concentrations on model protein cytochrome c (cyt c). Kinetics of heat-induced aggregation of cyt c suggest the nucleation independent first order aggregation kinetics. Aggregation of cyt c was studied in the presence of varying concentrations of BSA to assess its chaperone nature. At lower concentrations of BSA when the sub molar ratio of cyt c:BSA are 1:0.6 and 1:1.2, heat-induced unfolded cyt c promotes the aggregation of BSA. However, as the ratio of cyt c:BSA increases to 1:1.8, the aggregation of cyt c is reduced. When the concentration of BSA reaches physiological levels, yielding a cyt c:BSA ratio of 1:2.4, the rate of aggregation drastically decreases reflecting its chaperone potential. These observations indicate that under physiological conditions, macromolecular crowding stabilizes the native structure of both proteins and enhances their interaction that results in the reduced aggregation of cyt c. Additionally, the presence of the phytochemical chlorogenic acid at a sub-molar ratio of 1:1 stabilizes cyt c and prevents its unfolding and facilitates the binding of cyt c to BSA at physiological concentrations. This interaction further decreases the overall aggregation of cyt c and stabilizes its native fold.

This study aimed to investigate the role and underlying mechanisms of the platelet-derived growth factor (PDGF)/protein kinase B (AKT) signaling pathway in pressure overload-induced ventricular remodeling. Ventricular remodeling, a critical pathological process in heart failure, is commonly triggered by pressure overload. While PDGF is known to promote cell proliferation and growth, the AKT pathway is crucial for cell growth, survival, and metabolism. However, the specific role of the PDGF/AKT pathway in pressure overload-induced ventricular remodeling remains unclear. Thus, this study aimed to elucidate the precise mechanisms of PDGF/AKT involvement in this process using animal models and cell experiments. 45 female C57BL/6 mice were utilized, randomly divided into three groups: model group (M group, n = 15), control group (C group, n = 15), and experimental group (E group, n = 15). M group mice underwent thoracotomy without aortic constriction (AC). C group mice received phosphate-buffered saline (PBS) and dimethyl sulfoxide (DMSO) treatment following AC surgery. E group mice were treated with the PDGF receptor inhibitor AG1296 and PBS solution after AC surgery. Additionally, 293 T cells were categorized into three groups: PDGF shRNA transfected group (downregulating PDGF expression, D group), PDGF overexpression group (B group), and control group (NV group). Left ventricular end-systolic volume (LVESV) and ejection fraction (FS) of the mice were measured via echocardiography. Western blot analysis was conducted to assess the expression levels of p-AKT and t-AKT in myocardial tissues. Furthermore, myocardial cell area was measured using hematoxylin and eosin (HE) staining and image analysis software. The LVESV in the C group was significantly higher than in the M and E groups (48.32 ± 3.08 mL vs. 18.24 ± 3.19 mL and 25.44 ± 3.12 mL, P < 0.05). The FS in the C group was significantly lower compared to the M and E groups (21.18 ± 2.99% vs. 42.45 ± 3.02% and 26.89 ± 2.54%, P < 0.05). Western blot analysis revealed that p-AKT and t-AKT levels were significantly elevated in the C group and PDGF overexpression group (B group) compared to the M and PDGF shRNA groups (D group) (P < 0.05). HE staining showed a significant increase in myocardial cell cross-sectional area in the C and D groups, with the most pronounced enlargement in the D group (P < 0.05). PDGF facilitates pressure overload-induced ventricular remodeling and myocardial fibrosis. Inhibition of the PDGF/AKT signaling pathway effectively mitigates myocardial cell hypertrophy and ventricular remodeling. These findings offer novel potential targets and therapeutic strategies for the treatment of pressure overload-related heart failure.

Gastric cancer (GC) is a malignant tumor with high incidence rate. H3K9me3 is related to transcriptional suppression and modulated by histone methyltransferase suppressor of variegation 3-9 homolog 1 (SUV39H1). SUV39H1 is dysregulated in assorted cancers and exerts the regulatory function. Nevertheless, the specific biofunction of SUV39H1 in GC needs further confirmation. SUV39H1 and H3K9me3 expressions were tested through RT-qPCR and western blot. Colony formation, wound healing, and transwell assays were employed for testing cell behaviors. ChIP assay was utilized for assessing the interaction between H3K9me3 and aldolase B (ALDOB). Xenograft experiment was employed for measuring tumor growth. We found that SUV39H1 and H3K9me3 were overexpressed in GC tissues and cells. SUV39H1 knockdown notably suppressed GC cell proliferative, migratory, and invasive capabilities. The treatment of chaetocin or F5446 (inhibitors of SUV39H1 enzymatic activity) also restrained GC cell behaviors. In addition, we discovered that SUV39H1 could negatively regulate ALDOB expression. SUV39H1 depletion reduced H3K9me3 modification to ALDOB promoter region. In rescue assays, we proved that ALDOB reduction reversed the inhibitory functions of SUV39H1 silencing on GC progression. Furthermore, tumor growth of mice was suppressed by sh-SUV39H1 transfection, chaetocin treatment, or F5446 treatment. In conclusion, SUV39H1 promoted GC progression by modulating the H3K9me3/ALDOB axis.

Prostate cancer is a major cause of cancer-related mortality in men worldwide. The anti-proliferative activity of Gongronema latifolium leaf extracts on some cancer cells has been reported. Herein, we investigated the growth inhibitory effect of the Gongronema latilolium leaf methanol extract and isolated pregnane (iloneoside) against prostate cancer cell lines using the MTT cell proliferation assay, apoptosis quantification, cell cycle analysis using flow cytometry and computational analysis molecular docking, molecular dynamics simulation (MDs), binding free energy computation and cluster analysis. In addition, UPLC-ESI-TOFMS chemical fingerprinting of previously isolated compounds was performed. The extract inhibited the growth of the cell lines with an IC₅₀ of 49.3 µg/ml and 28.4 µg/ml for 24 h and 48 h, respectively, for PC3; and 43.7 µg/ml and 22.3 µg/ml for 24 h and 48 h, respectively, for DU145. Iloneoside demonstrated low inhibitory activities against PC3 and DU145 (IC₅₀ > 80 μM). Apoptotic quantification and cell cycle analysis further showed that iloneoside induced apoptosis in a few cells at a dose of 200 uM. The ensemble-based molecular docking of the iloneoside to BCL-XL and BCL-2 proteins, and docking to MCL-1, BCL-A1 and BFL-1 proteins, respectively, presented binding energies of -7.22 ± 0.5, -8.12 ± 0.55, -7.1, -7.2 and -6.3 kcal/mol, while the MM/PBSA binding free energy was -25.72 ± 7.22 and -27.76 ± 11.32 kcal/mol for BCL-XL and BCL-2 proteins. Furthermore, iloneoside was stable during the 100 ns MDs analysis, while the clustering of the MDs trajectories showed that the interactions were strongly preserved. Iloneoside, in part, or in synergy with other constituents, may be responsible for the antiproliferative activities of the leaf, subject to further investigation.

One of the leading causes of mortality for women is gynecologic cancer (GC). Numerous molecules (tumor suppressor genes or oncogenes) are involved in this form of cancer's invasion, metastasis, tumorigenic process, and therapy resistance. Currently, there is a shortage of efficient methods to eliminate these diseases, hence it is crucial to carry out more extensive studies on GCs. Novel pharmaceuticals are required to surmount this predicament. Highly conserved molecular chaperon, heat shock protein (HSP) 90, is essential for the maturation of recently produced polypeptides and offers a refuge for misfolding or denatured proteins to be turned around. In cancer, the client proteins of HSP90 play a role in the entire process of oncogenesis, which is linked to all the characteristic features of cancer. In this study, we explore the various functions of HSPs in GC progression. We also discuss their potential as promising targets for pharmacological therapy.

One of the common side effects of chemotherapy drugs is ovarian failure and uterine dysfunction, which can occur after the administration of doxorubicin and/or cyclophosphamide. In clinics, gonadotropin-releasing hormone agonists (GnRHa) are used to modulate the toxic effect of chemotherapy and intercept infertility with some controversy and limited histological knowledge. This study aimed to evaluate the serological and histological features of protective effects of triptorelin, (GnRHa), on utero-ovarian tissue in the mice treated with cyclophosphamide and/or doxorubicin. Forty-eight female BALB/c mice were randomly divided into 8 groups as follows: Group I: normal saline; Group II: triptorelin; Group III: cyclophosphamide; Group IV: doxorubicin; Group V: cyclophosphamide + doxorubicin; and Groups VI, VII, and VIII: after injection of cyclophosphamide, doxorubicin, or cyclophosphamide + doxorubicin, administration of triptorelin (1 mg/kg; intraperitoneally) for 15 consecutive days, respectively. On the 21st day, the ovaries and uterine horns were dissected and weighed. Then, tissue processing and staining were performed for further histological and stereological studies. Triptorelin treatment in the damaged groups significantly increased the number of primordial and pre-antral follicles and granulosa cells. It decreased the number of atretic follicles compared to cyclophosphamide and/or doxorubicin-treated groups (P < 0.05). Triptorelin also significantly improved the volume of the ovary, cortex, medulla, oocytes in the primordial and antral follicles, uterus, endometrium, myometrium, uterine glands, and endometrial blood vessels in the damaged groups (P < 0.05). Triptorelin treatment prevents the destructive effects of cyclophosphamide and/or doxorubicin on utero-ovarian tissue.

Parkinson's disease (PD) is a prevalent neurodegenerative disorder for which novel treatment approaches are continuously sought. This study investigates the role of high-mobility group A1 (HMGA1) in modulating inflammatory responses and oxidative stress injury in PD. We utilized the murine dopaminergic neuronal cell line MN9D, treating cells with 1-methyl-4-phenylpyridinium ion (MPP⁺) to mimic PD conditions. The expression levels of HMGA1 and insulin receptor substrate 2 (IRS2) were measured using quantitative polymerase chain reaction and Western blot assay. Cell damage was assessed with cell counting kit-8 and lactate dehydrogenase assays. Inflammatory response and oxidative stress were evaluated by quantifying interleukin (IL)-1β, IL-6, tumor necrosis factor-α, reactive oxygen species, superoxide dismutase, and malondialdehyde (MDA) levels using enzyme-linked immunosorbent assay and commercial kits. The binding interaction between HMGA1 and IRS2 was analyzed using chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays. Our findings revealed that MPP⁺ treatment increased the expression of HMGA1 and IRS2. Downregulation of HMGA1 enhanced cell viability, reduced inflammation, and mitigated oxidative stress in MPP⁺-induced cells. Further investigation demonstrated that HMGA1 bounded to the IRS2 promoter, enhancing IRS2 expression. Overexpression of IRS2 counteracted the protective effects of HMGA1 downregulation. In conclusion, HMGA1 exacerbates MPP⁺-induced cell damage by activating IRS2 transcription, which in turn heightens inflammation and oxidative stress. These findings suggest that targeting HMGA1 could be a potential therapeutic strategy for PD.