Aneuploidy, an abnormal chromosome number, has been linked to aging and age-associated diseases, but the underlying molecular mechanisms remain unknown. Here we show, through direct live-cell imaging of young, middle-aged, and old-aged primary human dermal fibroblasts, that aneuploidy increases with aging due to general dysfunction of the mitotic machinery. Increased chromosome mis-segregation in elderly mitotic cells correlates with an early senescence-associated secretory phenotype (SASP) and repression of Forkhead box M1 (FoxM1), the transcription factor that drives G2/M gene expression. FoxM1 induction in elderly and Hutchison–Gilford progeria syndrome fibroblasts prevents aneuploidy and, importantly, ameliorates cellular aging phenotypes. Moreover, we show that senescent fibroblasts isolated from elderly donors’ cultures are often aneuploid, and that aneuploidy is a key trigger into full senescence phenotypes. Based on this feedback loop between cellular aging and aneuploidy, we propose modulation of mitotic efficiency through FoxM1 as a potential strategy against aging and progeria syndromes.
This study evaluates the antifungal activity and mechanism of action of a new chemotype of Lavandula multifida from Portugal. The essential oil was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), and the minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) of the oil and its major compounds were determined against several pathogenic fungi responsible for candidosis, meningitis, dermatophytosis, and aspergillosis. The influence of the oil on the dimorphic transition in Candida albicans was also studied, as well as propidium iodide (PI) and FUN-1 staining of C. albicans cells by flow cytometry. The essential oil was characterized by high contents of monoterpenes, with carvacrol and cis-β-ocimene being the main constituents. The oil was more effective against dermatophytes and Cryptococcus neoformans, with MIC and MLC values of 0.16 μL/mL and 0.32 μL/mL, respectively. The oil was further shown to completely inhibit filamentation in C. albicans at concentrations below the respective MIC (0.08 μL/mL), with cis-β-ocimene being the main compound responsible for this inhibition (0.02 μL/mL). The flow cytometry results suggest a mechanism of action ultimately leading to cytoplasmic membrane disruption and cell death. L. multifida essential oil may be useful in complementary therapy to treat disseminated candidosis, since the inhibition of filamentation alone appears to be sufficient to treat this type of infection.
The oncogenic transcription factor FOXM1 has been previously shown to play a critical role in carcinogenesis by inducing cellular proliferation in multiple cancer types. A small-molecule compound, Robert Costa Memorial drug-1 (RCM-1), has been recently identified from high-throughput screen as an inhibitor of FOXM1 in vitro and in mouse model of allergen-mediated lung inflammation. In the present study, we examined antitumor activities of RCM-1 using tumor models. Treatment with RCM-1 inhibited tumor cell proliferation as evidenced by increased cell-cycle duration. Confocal imaging of RCM-1-treated tumor cells indicated that delay in cellular proliferation was concordant with inhibition of FOXM1 nuclear localization in these cells. RCM-1 reduced the formation and growth of tumor cell colonies in the colony formation assay. In animal models, RCM-1 treatment inhibited growth of mouse rhabdomyosarcoma Rd76-9, melanoma B16-F10, and human H2122 lung adenocarcinoma. RCM-1 decreased FOXM1 protein in the tumors, reduced tumor cell proliferation, and increased tumor cell apoptosis. RCM-1 decreased protein levels and nuclear localization of b-catenin, and inhibited protein-protein interaction between b-catenin and FOXM1 in cultured tumor cells and in vivo. Altogether, our study provides important evidence of antitumor potential of the small-molecule compound RCM-1, suggesting that RCM-1 can be a promising candidate for anticancer therapy.
This study evaluates the composition, antifungal activity and mechanism of action of the essential oil of Ferulago capillaris (Link ex Spreng.) Cout. and its main components, limonene and α-pinene, against clinically relevant yeasts and moulds. Essential oil from the plant's aerial parts was obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Essential oil showed high contents of limonene (30.9%) and α-pinene (35.8%). Minimum inhibitory concentrations (MICs) were measured according to the reference Clinical and Laboratory Standards Institute (CLSI) broth macrodilution protocols. Cell suspensions were subcultured in solid medium and the minimum fungicidal concentrations (MFCs) were rendered. The effect of essential oil on germ tube formation, mitochondrial function and ergosterol biosynthesis was investigated. Essential oil and α-pinene displayed low and similar MIC and MFC values against tested organisms (0.08 to 5.0 μL/mL), while limonene showed a weaker activity (0.32 to 20 μL/mL). Essential oil inhibited germ tube formation at sub-inhibitory concentrations on Candida albicans. The exposure of C. albicans to the essential oil resulted in impairment of mitochondrial functions in a dose-dependent manner. No difference in ergosterol content was observed in essential oil-treated C. albicans. F. capillaris and α-pinene display a broad fungicidal activity. The fungicidal activity of F. capillaris on C. albicans can be related to an induced oxidative stress which affects enzymes activity and the membrane potential of mitochondria. The essential oil of F. capillaris was shown to have potential for use in the development of clinically useful therapeutic preparations, particularly for topical application in the management of superficial mycoses.
Aging is a biological process characterized by the progressive deterioration of physiological functions known to be the main risk factor for chronic diseases and declining health. There has been an emerging connection between aging and aneuploidy, an aberrant number of chromosomes, even though the molecular mechanisms behind age-associated aneuploidy remain largely unknown. In recent years, several genetic pathways and biochemical processes controlling the rate of aging have been identified and proposed as aging hallmarks. Primary hallmarks that cause the accumulation of cellular damage include genomic instability, telomere attrition, epigenetic alterations and loss of proteostasis (López-Otín et al., Cell 153:1194-1217, 2013). Here we review the provocative link between these aging hallmarks and the loss of chromosome segregation fidelity during cell division, which could support the correlation between aging and aneuploidy seen over the past decades. Secondly, we review the systemic impacts of aneuploidy in cell physiology and emphasize how these include some of the primary hallmarks of aging. Based on the evidence, we propose a mutual causality between aging and aneuploidy, and suggest modulation of mitotic fidelity as a potential means to ameliorate healthy lifespan.
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