Collagen alteration is critical for epithelial tumor initiation and progression. Quantitatively linking collagen alteration and epithelial tumor progression is essential for developing an optical endoscopy to evaluate epithelial tumor progression. In this work, we established a quantitative link between collagen alteration and epithelial tumor progression using second harmonic generation (SHG) microscopy. It was found that SHG microscopy can provide quantitative features to effectively evaluate epithelial tumor progression, and to locate tumor and determine the margin of tumor regions. These results suggest that SHG microscopy has the potential in offering a noninvasive in vivo imaging tool to quantify epithelial tumor progression.

All the measurements were performed in backscattering geometry and demonstrated that nonlinear spectral imaging has the ability to differentiate hypertrophic scar tissue from normal skin based on noninvasive SHG imaging, and TPEF imaging revealed the microstructure and spectral features of collagen and elastin fibres. With the advances in spectral imaging apparatus miniaturization, we have good reason to believe that this approach can become a valuable tool for the in vivo pathophysiology study of human skin hypertrophic scars and for assessing the treatment responses of this disfiguring disease in clinic. It can also be used to track the development of hypertrophic scars and to study wound healing processes in a noninvasive fashion without biopsy, fixation, sectioning and the use of exogenous dyes or stains.

EBV-associated diseases other than PTLD are not rare in the recipients of allo-HSCT. The clinical manifestations of EBV end-organ diseases are similar to PTLD. EBV end-organ diseases had poorer response to rituximab-based therapy compared with PTLD.

Multiphoton microscopy was used to study the extracellular matrix of keloid at the molecular level without tissue fixation and staining. Direct imaging of collagen and elastin was achieved by second harmonic generation and two-photon excited fluorescence, respectively. The morphology and quantity of collagen and elastin in keloid were characterized and quantitatively analyzed in comparison to normal skin. The study demonstrated that in keloid, collagen content increased in both the upper dermis and the deep dermis, while elastin mostly showed up in the deep dermis and its quantity is higher compared to normal skin. This suggests the possibility that abnormal fibroblasts synthesized an excessive amount of collagen and elastin at the beginning of keloid formation, corresponding to the observed deep dermis, while after a certain time point, the abnormal fibroblast produced mostly collagen, corresponding to the observed upper dermis. The morphology of collagen and elastin in keloid was disrupted and presented different variations. In the deep dermis, elastic fibers showed node structure, while collagen showed obviously regular gaps between adjacent bundles. In the upper dermis, collagen bundles aligned in a preferred direction, while elastin showed as sparse irregular granules. This new molecular information provided fresh insight about the development process of keloid.

SUMMARYChloroplast biogenesis needs to be well coordinated with cell division and cell expansion during plant growth and development to achieve optimal photosynthesis rates. Previous studies showed that gibberellins (GAs) regulate many important plant developmental processes, including cell division and cell expansion. However, the relationship between chloroplast biogenesis with cell division and cell expansion, and how GA coordinately regulates these processes, remains poorly understood. In this study, we showed that chloroplast division was significantly reduced in the GA-deficient mutants of Arabidopsis (ga1-3) and Oryza sativa (d18-AD), accompanied by the reduced expression of several chloroplast division-related genes. However, the chloroplasts of both mutants exhibited increased grana stacking compared with their respective wild-type plants, suggesting that there might be a compensation mechanism linking chloroplast division and grana stacking. A time-course analysis showed that cell expansion-related genes tended to be upregulated earlier and more significantly than the genes related to chloroplast division and cell division in GA-treated ga1-3 leaves, suggesting the possibility that GA may promote chloroplast division indirectly through impacting leaf mesophyll cell expansion. Furthermore, our cellular and molecular analysis of the GA-response signaling mutants suggest that RGA and GAI are the major repressors regulating GA-induced chloroplast division, but other DELLA proteins (RGL1, RGL2 and RGL3) also play a role in repressing chloroplast division in Arabidopsis. Taken together, our data show that GA plays a critical role in controlling and coordinating cell division, cell expansion and chloroplast biogenesis through influencing the DELLA protein family in both dicot and monocot plant species.

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A prominent enzyme in organellar RNA metabolism is the exoribonuclease polynucleotide phosphorylase (PNPase), whose reversible activity is governed by the nucleotide diphosphate-inorganic phosphate ratio. In Chlamydomonas reinhardtii, PNPase regulates chloroplast transcript accumulation in response to phosphorus (P) starvation, and PNPase expression is repressed by the response regulator PSR1 (for PHOSPHORUS STARVATION RESPONSE1) under these conditions. Here, we investigated the role of PNPase in the Arabidopsis (Arabidopsis thaliana) P deprivation response by comparing wild-type and pnp mutant plants with respect to their morphology, metabolite profiles, and transcriptomes. We found that P-deprived pnp mutants develop aborted clusters of lateral roots, which are characterized by decreased auxin responsiveness and cell division, and exhibit cell death at the root tips. Electron microscopy revealed that the collapse of root organelles is enhanced in the pnp mutant under P deprivation and occurred with low frequency under P-replete conditions. Global analyses of metabolites and transcripts were carried out to understand the molecular bases of these altered P deprivation responses. We found that the pnp mutant expresses some elements of the deprivation response even when grown on a full nutrient medium, including altered transcript accumulation, although its total and inorganic P contents are not reduced. The pnp mutation also confers P status-independent responses, including but not limited to stress responses. Taken together, our data support the hypothesis that the activity of the chloroplast PNPase is involved in plant acclimation to P availability and that it may help maintain an appropriate balance of P metabolites even under normal growth conditions.Organisms require phosphorus (P) continually and in relatively high amounts, and in photosynthetic systems a major use is the regeneration of ribulose-1,6-bisphosphate, the acceptor for CO 2 fixation by Rubisco. Chloroplast inorganic phosphate (Pi) pools are also affected by starch biosynthesis, since the conversion of Glc-1-P to ADP-Glc, the penultimate step in the pathway, releases Pi through ATP hydrolysis. Starch is primarily synthesized during the day from excess triose phosphates and broken down at night, a step that consumes Pi through the action of starch phosphorylase and other enzymes (Zeeman et al., 2007). Thus, P is a major player in chloroplast metabolism and is intimately integrated into the carbon budget of plant cells.Chloroplast P is also required for processes not directly related to photosynthesis, such as gene expression. In particular, the chloroplast ribonuclease polynucleotide phosphorylase (PNPase) both consumes and liberates P. PNPase in bacteria (Soreq and Littauer, 1977) and chloroplasts (Baginsky et al., 2001) is a homotrimer that degrades RNA through phosphorylytic attack, but it also readily synthesizes polynucleotides using nucleotide diphosphate or nucleotide triphosphate precursors, a reaction that generates Pi or inorganic pyroph...

Multiphoton microscopic imaging of collagen plays an important role in noninvasive diagnoses of human tissue. In this study, two-photon fluorescence and second-harmonic generation (SHG) imaging of collagen in human skin dermis and submucosa of colon and stomach tissues were investigated based on multiphoton microscopy (MPM). Our results show that multiphoton microscopic image of collagen bundles exhibits apparently different pattern in human tissues. The collagen bundles can simultaneously reveal its SHG and two-photon excited fluorescence images in the submucosa of colon and stomach, whereas it solely emit SHG signal in skin dermis. The intensity spectral information from tissues further demonstrated the above results. This indicates that collagen bundles have completely different space arrangement in these tissues. Our experimental results bring more detailed information of collagen for the application of MPM in human noninvasive imaging.