OBJECTIVES: To develop a novel in vitro skin glycation model as a screening tool for topical formulations with antiglycation properties and to further characterize, at the molecular level, the glycation stress-driven skin ageing mechanism.
METHODS: The glycation model was developed using human reconstituted full-thickness skin; the presence of N(ε) -(carboxymethyl) lysine (CML) was used as evidence of the degree of glycation. Topical application of emulsion containing a well-known antiglycation compound (aminoguanidine) was used to verify the sensitivity and robustness of the model. Cytokine immunoassay, quantitative real-time polymerase chain reaction and histological analysis were further implemented to characterize the molecular mechanisms of skin ageing in the skin glycation model.
RESULTS: Transcriptomic and cytokine profiling analyses in the skin glycation model demonstrated multiple biological changes, including extracellular matrix catabolism, skin barrier function impairment, oxidative stress and subsequently the inflammatory response. Darkness and yellowness of skin tone observed in the in vitro skin glycation model correlated well with the degree of glycation stress.
CONCLUSIONS: The newly developed skin glycation model in this study has provided a new technological dimension in screening antiglycation properties of topical pharmaceutical or cosmeceutical formulations. This study concomitantly provides insights into skin ageing mechanisms driven by glycation stress, which could be useful in formulating skin antiageing therapy in future studies.
Methods: The mechanism involved in the cytotoxic activities of F5 against MCF7 cells was elucidated by flow cytometry-based apoptosis detection, caspases activity measurement, and expression profiling of apoptosis markers by western blotting. Molecular attributes of F5 were further mined from L. rhinocerus's published genome and transcriptome for future exploration.
Results and Discussion: Apoptosis induction in MCF7 cells by F5 may involve a cross-talk between the extrinsic and intrinsic apoptotic pathways with upregulation of caspase-8 and -9 activities and a marked decrease of Bcl-2. On the other hand, the levels of pro-apoptotic Bax, BID, and cleaved BID were increased accompanied by observable actin cleavage. At gene level, F5 composed of three predicted non-synonymous single nucleotide polymorphisms (T > C) and an alternative 5' splice site.
Conclusions: Findings from this study provide an advanced framework for further investigations on cancer therapeutics development from L. rhinocerus.
METHODS: We measured levels of 30 chemokines and cytokines in serum and cerebrospinal fluid (CSF) samples from Malaysian children hospitalized with EV71 infection (n = 88), comprising uncomplicated HFMD (n = 47), meningitis (n = 8), acute flaccid paralysis (n = 1), encephalitis (n = 21), and encephalitis with cardiorespiratory compromise (n = 11). Four of the latter patients died.
RESULTS: Both pro-inflammatory and anti-inflammatory mediator levels were elevated, with different patterns of mediator abundance in the CSF and vascular compartments. Serum concentrations of interleukin 1β (IL-1β), interleukin 1 receptor antagonist (IL-1Ra), and granulocyte colony-stimulating factor (G-CSF) were raised significantly in patients who developed cardio-respiratory compromise (P = .013, P = .004, and P < .001, respectively). Serum IL-1Ra and G-CSF levels were also significantly elevated in patients who died, with a serum G-CSF to interleukin 5 ratio of >100 at admission being the most accurate prognostic marker for death (P < .001; accuracy, 85.5%; sensitivity, 100%; specificity, 84.7%).
CONCLUSIONS: Given that IL-1β has a negative inotropic action on the heart, and that both its natural antagonist, IL-1Ra, and G-CSF are being assessed as treatments for acute cardiac impairment, the findings suggest we have identified functional markers of EV71-related cardiac dysfunction and potential treatment options.