Quantitative chemical imaging with multiplex stimulated Raman scattering microscopy.

Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Journal of the American Chemical Society (Impact Factor: 11.44). 02/2012; 134(8):3623-6. DOI: 10.1021/ja210081h
Source: PubMed

ABSTRACT Stimulated Raman scattering (SRS) microscopy is a newly developed label-free chemical imaging technique that overcomes the speed limitation of confocal Raman microscopy while avoiding the nonresonant background problem of coherent anti-Stokes Raman scattering (CARS) microscopy. Previous demonstrations have been limited to single Raman band measurements. We present a novel modulation multiplexing approach that allows real-time detection of multiple species using the fast Fourier transform. We demonstrate the quantitative determination of chemical concentrations in a ternary mixture. Furthermore, two imaging applications are pursued: (1) quantitative determination of oil content as well as pigment and protein concentration in microalgae cultures; and (2) 3D high-resolution imaging of blood, lipids, and protein distribution in ex vivo mouse skin tissue. We believe that quantitative multiplex SRS uniquely combines the advantage of fast label-free imaging with the fingerprinting capability of Raman spectroscopy and enables numerous applications in lipid biology as well as biomedical imaging.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: -Diabetic cardiomyopathy, which contributes to more than 50% diabetic death, is featured by myocardial lipid accumulation, hypertrophy, fibrosis, and cardiac dysfunction. The mechanism underlying diabetic cardiomyopathy is poorly understood. Recent studies have shown that a striated muscle-specific E3 ligase Mitsugumin 53 (MG53, or TRIM72) constitutes a primary causal factor of systemic insulin resistance and metabolic disorders. Although it is most abundantly expressed in myocardium, the biological and pathological roles of MG53 in triggering cardiac metabolic disorders remain elusive. -Here we show that cardiac-specific transgenic expression of MG53 induces diabetic cardiomyopathy in mice. Specifically, MG53 transgenic mouse develops severe diabetic cardiomyopathy at 20 weeks of age, as manifested by insulin resistance, compromised glucose uptake, increased lipid accumulation, myocardial hypertrophy, fibrosis, and cardiac dysfunction. Overexpression of MG53 leads to insulin resistant via destabilizing insulin receptor and insulin receptor substrate 1. More importantly, we identified a novel role of MG53 in transcriptional upregulation of peroxisome proliferation-activated receptor alpha (PPAR-α) and its target genes, resulting in lipid accumulation and lipid toxicity, thereby contributing to diabetic cardiomyopathy. -Our results suggest that overexpression of myocardial MG53 is sufficient to induce diabetic cardiomyopathy via dual mechanisms involving upregulation of PPAR-α and impairment of insulin signaling. These findings not only reveal a novel function of MG53 in regulating cardiac PPAR-α gene expression and lipid metabolism, but also underscore MG53 as an important therapeutic target for diabetes and associated cardiomyopathy.
    Circulation 01/2015; · 14.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A straightforward method for spectral stimulated Raman scattering (SRS) microscopy is to measure the scanned gain/loss spectrum of a white probe light from a photonic crystal fibre (PCF). However, the intensity of the white light noise is a serious problem for SRS microscopy. In this study, we have demonstrated simultaneous two-wavelength SRS microscopy with PCF through balanced detection suitable for spectroscopy with a modification of an auto-balance scheme. The developed auto-balance detection system suppresses the degradation of noise cancellation performance caused by a sample, and is suitable for spectral SRS imaging with simple and robust optics.
    Journal of Physics D Applied Physics 08/2014; 47(34):345401. · 2.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Quantitative single-cell analysis enables the characterization of cellular systems with a level of detail that cannot be achieved with ensemble measurement. In this Feature we explore quantitative cellular imaging applications with nonlinear microscopy techniques. We first offer an introductory tutorial on nonlinear optical processes and then survey a range of techniques that have proven to be useful for quantitative live cell imaging without fluorescent labels.
    Analytical Chemistry 07/2014; · 5.83 Impact Factor

Full-text (2 Sources)

Available from
Jul 10, 2014