5-Bromo-2'-deoxyuridine induced effluvium via p53-mediated CD326-positive keratinocyte apoptosis in C57BL/6 mice.

Anagen effluvium develops because of disturbances in the hair follicle cycle, leading to acute and severe hair loss in humans. The objective of this study was to establish a mouse model of anagen effluvium by 5-bromo-2'-deoxyuridine (BrdU) treatment, and evaluate the pathological changes and underlying mechanisms. We treated 9-10-day-old pups and 3-7-week-old C57BL/6 mice with BrdU. After successfully inducing hair loss in the neonatal pups, microscopic, immunohistochemical and flow cytometry analyses were conducted. BrdU induced early onset alopecia in neonates and caused epidermal thickening and hair shaft breakage. BrdU appeared to incorporate the CD326-positive keratinocyte layer and induced p53-related apoptosis. Keratinocyte apoptosis caused immune cell infiltration in the dermal region; M2 macrophages and neutrophils were dominant. The BrdU-induced hair loss was dose-dependent, and alopecia was visible at a dose range of 25-200 µg/g bodyweight. The BrdU-induced anagen effluvium mouse model is novel and easily established by administrating four simple BrdU injections to pups; these mice showed synchronized onset of alopecia symptoms with little individual variation. Moreover, this model showed an alopecia phenotype similar to that of human anagen effluvium with acute, severe and widespread hair loss.

Premature mammary gland involution with repeated corticosterone injection in interleukin 10-deficient mice.

Recently, we found that maternal stress could induce premature mammary gland involution in interleukin 10 knock out (IL-10-/-) mice. To elucidate correlation between stress, IL-10, and mammary gland involution, corticosterone was injected into the lactating wild type and IL-10-deficient mice and assessed mammary gland phenotype. Repetitive corticosterone injection developed premature mammary gland involution only in B6.IL-10-/- mice; moreover, it induced alopecia in nursing pups. Corticosterone injection induced several typical changes such as mammary gland epithelial cell apoptosis, macrophage infiltration, fat deposition in adipocyte, STAT3 phosphorylation, and upregulation of tyrosine hydroxylase gene in adrenal gland. Overall incidence of pup alopecia and mammary gland involution was relatively high in corticosterone than control B6.IL-10-/- group (57% vs. 20%). Our finding demonstrates that IL-10 is important for stress modulation, and B6.Il-10-/- with corticosterone has several advantage such as simple to establish, well-defined onset of mammary gland involution, high incidence, and inducing pup alopecia.

Size-dependent plasmonic responses of single gold nanoparticles for analysis of biorecognition.

We report the use of plasmonic responses of single gold nanoparticles (AuNPs) with various sizes for the analysis of biomolecular recognition. We also describe the relationship between particle size and plasmonic response induced by the binding of receptors and target analytes. To investigate the plasmonic response of AuNPs, Rayleigh light scattering spectra were collected from individual AuNPs using a dark-field microspectroscopy system. Using prostate-specific antigen (PSA) as a model, the linear dynamic range was obtained in the concentration range of 10(-4) to 10 ng/ml, with the smallest detectable concentration at 0.1 pg/ml corresponding to localized surface plasmon resonance (LSPR) λ(max) shifts of approximately 2.95 nm. This result indicates that individual AuNPs can be used for development of a very sensitive, robust, simple, and label-free biosensor to detect protein biomarkers. Furthermore, the method possesses great potential for monitoring other biological interactions.

A strategy for the ultrasensitive detection of cancer biomarkers based on the LSPR response of a single AuNP.

A biosensor based on the localized surface plasmon resonance (LSPR) response of a single Au nanoparticle was fabricated for the highly sensitive detection and quantification of a specific cancer biomarker. The spectral position changes of single Au nanoparticles induced by the binding of adsorbates and target analytes were effectively utilized as sensing tools. The LSPR responses of single Au nanoparticles were obtained by tracking the wavelength shift of the corresponding resonant Rayleigh light scattering spectra via dark-field microspectroscopy. Using prostate specific antigen as a model, an LSPR lambda max shift of about 2.75 nm was recorded by a primary immunoresponse corresponding to 0.1 pg/mL of the target antigen. The sensitivity of the immunoassay can be substantially enhanced, however, by a sandwich strategy. A PSA polyclonal antibody was used as an amplifying agent in the strategy. As a result, the linear dynamic range of the sensing platform was determined to be within the concentration range of 10(-4) to 0.1 ng/mL and a detectable minimum concentration of 0.1 pg/mL was identified, with an LSPR lambda max shift of about 4.96 nm. The results indicate that the aforementioned approach can significantly contribute to the fabrication of ultrasensitive biosensors, allowing the quantitative analysis of cancer-associated proteins