Methods: Human neuroblastoma cells SH-SY5Y (as a neuronal model) and human glioblastoma cells T98G (as an astrocytic model), were treated with 100-500 µM PA, oleic acid (OA) or lauric acid (LA) for 24 h or 48 h, and their cell viability was assessed by 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of stable overexpression of γ-synuclein (γ-syn), a neuronal protein recently recognized as a novel regulator of lipid handling in adipocytes, and transient overexpression of Parkinson's disease (PD) α-synuclein [α-syn; wild-type (wt) and its pathogenic mutants A53T, A30P and E46K] in SH-SY5Y and T98G cells, were also evaluated. The effects of co-treatment of PA with paraquat (PQ), a Parkinsonian pesticide, and leptin, a hormone involved in the brain-adipose axis, were also assessed. Cell death mode and cell cycle were analyzed by Annexin V/PI flow cytometry. Reactive oxygen species (ROS) level was determined using 2',7'-dichlorofluorescien diacetate (DCFH-DA) assay and lipid peroxidation level was determined using thiobarbituric acid reactive substances (TBARS) assay.
Results: MTT assay revealed dose- and time-dependent PA cytotoxicity on SH-SY5Y and T98G cells, but not OA and LA. The cytotoxicity was significantly lower in SH-SY5Y-γ-syn cells, while transient overexpression of wt α-syn or its PD mutants (A30P and E46K, but not A53T) modestly (but still significantly) rescued the cytotoxicity of PA in SH-SY5Y and T98G cells. Co-treatment of increasing concentrations of PQ exacerbated PA's neurotoxicity. Pre-treatment of leptin, an anti-apoptotic adipokine, did not successfully rescue SH-SY5Y cells from PA-induced cytotoxicity-suggesting a mechanism of PA-induced leptin resistance. Annexin V/PI flow cytometry analysis revealed PA-induced increase in percentages of cells in annexin V-positive/PI-negative quadrant (early apoptosis) and subG0-G1 fraction, accompanied by a decrease in G2-M phase cells. The PA-induced ROS production and lipid peroxidation was at greater extent in T98G as compared to that in SH-SY5Y.
Discussion: In conclusion, PA induces apoptosis by increasing oxidative stress in neurons and astrocytes. Taken together, the results suggest that HFD may cause neuronal and astrocytic damage, which indirectly proposes that CNS pathologies involving neuroinflammation and reactive gliosis could be prevented via the diet regimen.
Methods: In this study, wtHALT-1 (wild type) and its Y110A mutated binding domain counterpart (mHALT-1) were produced and evaluated for their cytotoxic and apoptotic effects on various cancer cell lines. A total of seven different tumour and non-tumour cell lines including HeLa, HepG2, SW-620, MCF-7, CCD841CoN, NHDF and HCT116 were used. Immunofluorescence assays were used to observe membrane binding and localization changes between both HALT-1 recombinant proteins based on 6xHis-tag detection.
Result: Based on MTT data, mHALT-1 demonstrated a significant reduction of 82% ± 12.21% in cytotoxic activity across all cell lines after the membrane recognition domain had been mutated in comparison to the wtHALT-1. Annexin V FITC/PI assay data also indicated that HeLa, HepG2 and MCF-7 demonstrated an apoptosis-mediated cell death after being treated with wtHALT-1. Additionally, a notable difference between wtHALT-1 and mHALT-1 binding affinity was clearly observed where emission of green fluorescence along the cell membrane was observed only in wtHALT-1 treated cells.
Discussion: These results suggest that mHALT-1 (Y110A) can be potentially developed as a toxin-moiety candidate for the development of future immunotoxins against various human cell-based diseases.
Objective: This study investigated the in vitro and in vivo anti-tumour effects of coconut water vinegar on 4T1 breast cancer cells.
Methods: The 4T1 cells were treated with freeze-dried coconut water vinegar and subjected to MTT cell viability, BrdU, annexin V/PI apoptosis, cell cycle and wound healing assays for the in vitro analysis. For the in vivo chemopreventive evaluation, mice challenged with 4T1 cells were treated with 0.08or 2.00 mL/kg body weight of fresh coconut water vinegar for 28 days. Tumour weight, apoptosis of tumour cells, metastasis and immunity of untreated mice and coconut water vinegar-treated 4T1 challenged mice were compared.
Results: Freeze-dried coconut water vinegar reduced the cell viability, induced apoptosis and delayed the wound healing effect of 4T1 cells in vitro. In vivo, coconut water vinegar delayed 4T1 breast cancer progression in mice by inducing apoptosis and delaying the metastasis. Furthermore, coconut water vinegar also promoted immune cell cytotoxicity and production of anticancer cytokines. The results indicate that coconut water vinegar delays breast cancer progression by inducing apoptosis in breast cancer cells, suppressing metastasis and activating anti-tumour immunity.
Conclusion: Coconut water vinegar is a potential health food ingredient with a chemopreventive effect.
Objective: In this study, we aimed to examine the effect of MAN on human lung cancer and reveal the underlying molecular mechanism.
Methods: MTT assay was conducted to measure cell viability. Annexin V-FITC/PI staining was used to detect cell apoptosis. Confocal microscope was performed to determine the formation of autophagosomes and autolysosomes. Flow cytometry was performed to quantify cell death. Western blotting was used to determine the related-signaling pathway.
Results: In the present study, we demonstrated for the first time that MAN inhibitd cell proliferation and induced cell apoptosis in human non-small-cell lung carcinoma (NSCLC) cells. We found that MAN treatment dysregulated mitochondrial function and led to mitochondrial apoptosis in A549 and PC9 cells. Meanwhile, MAN enhanced autophagy flux by the increase of autophagosome formation, the fusion of autophagsomes and lysosomes and lysosomal function. Moreover, mTOR signaling pathway, a classical pathway regualting autophagy, was inhibited by MAN in a time- and dose-dependent mannner, resulting in autophagy induction. Interestingly, autophagy inhibition by CQ or Atg5 knockdown attenuated cell apoptosis by MAN, indicating that autophagy serves as cell death. Furthermore, autophagy-mediated cell death by MAN can be blocked by reactive oxygen species (ROS) scavenger NAC, indicating that ROS accumulation is the inducing factor of apoptosis and autophagy. In summary, we revealed the molecular mechanism of MAN against lung cancer through apoptosis and autophagy, suggesting that MAN might be a novel therapeutic agent for NSCLC treatment.