ATP1A1 Mutant in Aldosterone-Producing Adenoma Leads to Cell Proliferation

The molecular mechanisms by which ATP1A1 mutation-mediated cell proliferation or tumorigenesis in aldosterone-producing adenomas (APAs) have not been elucidated. First, we investigated whether the APA-associated ATP1A1 L104R mutation stimulated cell proliferation. Second, we aimed to clarify the molecular mechanisms by which the ATP1A1 mutation-mediated cell proliferated. We performed transcriptome analysis in APAs with ATP1A1 mutation. ATP1A1 L104R mutation were modulated in human adrenocortical carcinoma (HAC15) cells (ATP1A1-mutant cells), and we evaluated cell proliferation and molecular signaling events. Transcriptome and immunohistochemical analysis showed that Na/K-ATPase (NKA) expressions in ATP1A1 mutated APA were more abundant than those in non-functioning adrenocortical adenoma or KCNJ5 mutated APAs. The significant increase of number of cells, amount of DNA and S-phase population were shown in ATP1A1-mutant cells. Fluo-4 in ATP1A1-mutant cells were significantly increased. Low concentration of ouabain stimulated cell proliferation in ATP1A1-mutant cells. ATP1A1-mutant cells induced Src phosphorylation, and low concentration of ouabain supplementation showed further Src phosphorylation. We demonstrated that NKAs were highly expressed in ATP1A1 mutant APA, and the mutant stimulated cell proliferation and Src phosphorylation in ATP1A1-mutant cells. NKA stimulations would be a risk factor for the progression and development to an ATP1A1 mutant APA.

Thermal Shock and Ciprofloxacin Act Orthogonally on Pseudomonas aeruginosa Biofilms

Bacterial biofilm infections are a major liability of medical implants, due to their resistance to both antibiotics and host immune response. Thermal shock can kill established biofilms, and some evidence suggests antibiotics may enhance this efficacy, despite having an insufficient effect themselves. The nature of this interaction is unclear, however, complicating efforts to integrate thermal shock into implant infection treatment. This study aimed to determine whether these treatments were truly synergistic or simply orthogonal (i.e., independent). Pseudomonas aeruginosa biofilms of different architectures and stationary-phase population density were subjected to various thermal shocks, antibiotic exposures, or combinations thereof, and examined either immediately after treatment or after subsequent reincubation. Population decreases from the combination treatment matched the product of the decreases of individual treatments, indicating their orthogonality. However, reincubation showed binary behavior, where biofilms with an immediate population decrease beyond a critical factor (~104) died off completely during reincubation, while biofilms with a smaller immediate decrease regrew. This critical factor was independent of the initial population density and the combination of treatments that achieved the immediate decrease. While antibiotics do not appear to enhance thermal shock directly, their contribution to achieving a critical population decrease for biofilm elimination can make the treatments appear strongly synergistic, strongly decreasing the intensity of thermal shock needed.

Mycobacterial Populations Partly Change the Proportions of the Cells Undergoing Asymmetric/Symmetric Divisions in Response to Glycerol Levels in Growth Medium

Twenty to thirty percent of the septating mycobacterial cells of the mid-log phase population showed highly deviated asymmetric constriction during division (ACD), while the remaining underwent symmetric constriction during division (SCD). The ACD produced short-sized cells (SCs) and normal/long-sized cells (NCs) as the sister–daughter cells, but with significant differential susceptibility to antibiotic/oxidative/nitrite stress. Here we report that, at 0.2% glycerol, formulated in the Middlebrook 7H9 medium, a significantly high proportion of the cells were divided by SCD. When the glycerol concentration decreased to 0.1% due to cell-growth/division, the ACD proportion gradually increased until the ACD:SCD ratio reached ~50:50. With further decrease in the glycerol levels, the SCD proportion increased with concomitant decrease in the ACD proportion. Maintenance of glycerol at 0.1%, through replenishment, held the ACD:SCD proportion at ~50:50. Transfer of the cells from one culture with a specific glycerol level to the supernatant from another culture, with a different glycerol level, made the cells change the ACD:SCD proportion to that of the culture from which the supernatant was taken. RT-qPCR data showed the possibility of diadenosine tetraphosphate phosphorylase (MSMEG_2932), phosphatidylinositol synthase (MSMEG_2933), and a Nudix family hydrolase (MSMEG_2936) involved in the ACD:SCD proportion-change in response to glycerol levels. We also discussed its physiological significance.

Molecular Properties of Bare and Microhydrated Vitamin B5–Calcium Complexes

Pantothenic acid, also called vitamin B5, is an essential nutrient involved in several metabolic pathways. It shows a characteristic preference for interacting with Ca(II) ions, which are abundant in the extracellular media and act as secondary mediators in the activation of numerous biological functions. The bare deprotonated form of pantothenic acid, [panto-H]−, its complex with Ca(II) ion, [Ca(panto-H)]+, and singly charged micro-hydrated calcium pantothenate [Ca(panto-H)(H2O)]+ adduct have been obtained in the gas phase by electrospray ionization and assayed by mass spectrometry and IR multiple photon dissociation spectroscopy in the fingerprint spectral range. Quantum chemical calculations at the B3LYP(-D3) and MP2 levels of theory were performed to simulate geometries, thermochemical data, and linear absorption spectra of low-lying isomers, allowing us to assign the experimental absorptions to particular structural motifs. Pantothenate was found to exist in the gas phase as a single isomeric form showing deprotonation on the carboxylic moiety. On the contrary, free and monohydrated calcium complexes of deprotonated pantothenic acid both present at least two isomers participating in the gas-phase population, sharing the deprotonation of pantothenate on the carboxylic group and either a fourfold or fivefold coordination with calcium, thus justifying the strong affinity of pantothenate for the metal.

The Flavonol Isoquercitrin Promotes Mitochondrial-Dependent Apoptosis in SK-Mel-2 Melanoma Cell via the PI3K/AKT/mTOR Pathway

Isoquercitrin (IQ), a major flavonol present in Prunus mume fruit, has gained much attention in recent studies because of its superior bioavailability and physiological effects. In this study, the anti-cancer mechanism of IQ against human melanoma, particularly its effect on the mitochondria-mediated apoptosis, was investigated. Treatment with IQ at 25 μM concentration effectively inhibited the proliferation of SK-MEL-2 skin cancer cells while the same concentration did not exhibit cytotoxicity against human keratinocytes HaCaT. Morphological analysis and clonogenic assay also showed that IQ can alter the growth and long-term survival of SK-MEL-2 cells. IQ also induced apoptosis in the melanoma cells as manifested in the nuclear morphology changes, DNA fragmentation, increase in the apoptosis rate (17.69% at 25 μM) and accumulation of sub-G1 cell cycle phase population (19.55% at 25 μM). Western blot analysis revealed the involvement of the mitochondrial apoptosis signaling pathway in the anti-cancer property of IQ. Treatment with IQ resulted in the decrease in the levels of procaspase-8 and -9, and Bcl-2 protein, and an increase in the expression of cleaved PARP and Bax. Moreover, AIF and Endo G protein expression increased, indicating a caspase-independent mitochondrial-mediated apoptosis. The anti-proliferative activity of IQ against SK-MEL-2 can also be attributed to the downregulation of the PI3K/AktmTOR signaling pathway. These findings showed that IQ can be developed into a chemopreventive therapeutic agent against the melanoma cells.

Fatty Acid Inhibition Sensitizes Androgen-Dependent and -Independent Prostate Cancer to Radiotherapy via FASN/NF-κB Pathway

Elevated fatty acid synthase (FASN) has been reported in both androgen-dependent and -independent prostate cancers. Conventional treatment for prostate cancer is radiotherapy (RT); however, the following radiation-induced radioresistance often causes treatment failure. Upstream proteins of FASN such as Akt and NF-κB are found increased in the radioresistant prostate cancer cells. Nevertheless, whether inhibition of FASN could improve RT outcomes and reverse radiosensitivity of prostate cancer cells is still unknown. Here, we hypothesised that orlistat, a FASN inhibitor, could improve RT outcomes in prostate cancer. Orlistat treatment significantly reduced the S phase population in both androgen-dependent and -independent prostate cancer cells. Combination of orlistat and RT significantly decreased NF-κB activity and related downstream proteins in both prostate cancer cells. Combination effect of orlistat and RT was further investigated in both LNCaP and PC3 tumour-bearing mice. Combination treatment showed the best tumour inhibition compared to that of orlistat alone or RT alone. These results suggest that prostate cancer treated by conventional RT could be improved by orlistat via inhibition of FASN.

Giant resistive switching in mixed phase BiFeO3via phase population control

Giant resistive switching is achieved through control of mixed-phase microstructures in BiFeO3via different stimuli.

Correction: Giant resistive switching in mixed phase BiFeO3via phase population control

Correction for ‘Giant resistive switching in mixed phase BiFeO3via phase population control’ by David Edwards et al., Nanoscale, 2018, 10, 17629–17637.