Longitudinal Awake Imaging of Deep Mouse Brain Microvasculature with Super-resolution Ultrasound Localization Microscopy.

Super-resolution ultrasound localization microscopy (ULM) is an emerging imaging modality that resolves capillary-scale microvasculature in deep tissues. However, existing preclinical ULM applications are largely constrained to anesthetized animals, introducing confounding vascular effects such as vasodilation and altered hemodynamics. As such, ULM quantifications (e.g., vessel diameter, density, and flow velocity) may be confounded by the use of anesthesia, undermining the usefulness of ULM in practice. Here we introduce a method to address this limitation and achieve ULM imaging in awake mouse brain. Pupillary monitoring was used to confirm the awake state during ULM imaging. ULM revealed that veins showed a greater degree of vascularity reduction from anesthesia to awake states than did arteries. The reduction was most significant in the midbrain and least significant in the cortex. ULM also revealed a significant reduction in venous blood flow velocity across different brain regions under awake conditions. Serial in vivo imaging of the same animal brain at weekly intervals demonstrated the highly robust longitudinal imaging capability of the proposed technique. This is the first study demonstrating longitudinal ULM imaging in the awake mouse brain, which is essential for many ULM brain applications that require awake and behaving animals.

Up-regulation of cofilin-1 in cell senescence associates with morphological change and p27kip1 -mediated growth delay.

Morphological change is an explicit characteristic of cell senescence, but the underlying mechanisms remains to be addressed. Here, we demonstrated, after a survey of various actin-binding proteins, that the post-translational up-regulation of cofilin-1 was essential for the reduced rate of actin depolymerization morphological enlargement in senescent cells. Additionally, up-regulated cofilin-1 mainly existed in the serine-3 phosphorylated form, according to the 2D gel immunoblotting assay. The up-regulation of cofilin-1 was also detected in aged mammalian tissues. The over-expression of wild-type cofilin-1 and constitutively phosphorylated cofilin-1 promoted cell senescence with an increased cell size. Additionally, senescent phenotypes were also reduced by knockdown of total cofilin-1, which led to a decrease in phosphorylated cofilin-1. The senescence induced by the over-expression of cofilin-1 was dependent on p27Kip1 , but not on the p53 and p16INK4 expressions. The knockdown of p27Kip1 alleviated cell senescence induced by oxidative stress or replicative stress. We also found that the over-expression of cofilin-1 induced the expression of p27Kip1 through transcriptional suppression of the transcriptional enhancer factors domain 1 (TEAD1) transcription factor. The TEAD1 transcription factor played a transrepressive role in the p27Kip1  gene promoter, as determined by the promoter deletion reporter gene assay. Interestingly, the down-regulation of TEAD1 was accompanied by the up-regulation of cofilin-1 in senescence. The knockdown and restoration of TEAD1 in young cells and old cells could induce and inhibit p27Kip1 and senescent phenotypes, respectively. Taken together, the current data suggest that cofilin-1/TEAD1/p27Kip1 signaling is involved in senescence-related morphological change and growth arrest.

Involvement of 8-O-acetylharpagide for Ajuga taiwanensis mediated suppression of senescent phenotypes in human dermal fibroblasts.

Herbal medicines are attractive agents for human care. In this study, we found that the alcohol extract of Ajuga taiwanensis (ATE) screened from a chemical bank exhibited potent capacity for suppressing senescence associated biomarkers, including SA-ß-gal and up-regulated p53 in old human dermal fibroblasts (HDFs) without induction of significant cytotoxicity up to 100 µg/ml. Concomitantly, cells re-entered the cell cycle by reducing G1 phase arrest and increasing cell growth rate. The ATE was further partitioned to obtain the sub-fractions of n-butanol (BuOH), ethyl acetate (EA) and water. The BuOH and water sub-fractions exhibited less effects on prohibition of cell growth than the EA sub-fraction. All of these sub-fractions exhibited the ability on suppressing SA-ß-gal and p53 of old HDFs as low as 5-10 µg/ml. Under the activity guided fractionation and isolation, a major active constituent named AT-1 was isolated. The AT-1 was further identified as 8-O-acetylharpagide by structural analysis, and it could suppress SA-ß-gal and p53 of old HDFs below 10 µM. In addition, the intracellular reactive oxygen species (ROS) levels of old HDFs were suppressed by ATE, the sub-fractions of BuOH and water, and AT-1. However, the EA sub-fraction showed little ability on suppression of ROS. Furthermore, we performed an in vivo study using aging mice to be fed with ATE and the sub-fractions followed by immunohistochemical (IHC) staining. The expression of p53 and SA-ß-gal was significantly reduced in several tissue sections, including skin, liver, kidney, and spleen. Taken together, current data demonstrated that A. taiwanensis could suppress cellular senescence in HDFs, and might be used for health care.

Involvement of Differentially Expressed microRNAs in the PEGylated Liposome Encapsulated 188Rhenium-Mediated Suppression of Orthotopic Hypopharyngeal Tumor.

Hypopharyngeal cancer (HPC) accounts for the lowest survival rate among all types of head and neck cancers (HNSCC). However, the therapeutic approach for HPC still needs to be investigated. In this study, a theranostic 188Re-liposome was prepared to treat orthotopic HPC tumors and analyze the deregulated microRNA expressive profiles. The therapeutic efficacy of 188Re-liposome on HPC tumors was evaluated using bioluminescent imaging followed by next generation sequencing (NGS) analysis, in order to address the deregulated microRNAs and associated signaling pathways. The differentially expressed microRNAs were also confirmed using clinical HNSCC samples and clinical information from The Cancer Genome Atlas (TCGA) database. Repeated doses of 188Re-liposome were administrated to tumor-bearing mice, and the tumor growth was apparently suppressed after treatment. For NGS analysis, 13 and 9 microRNAs were respectively up-regulated and down-regulated when the cutoffs of fold change were set to 5. Additionally, miR-206-3p and miR-142-5p represented the highest fold of up-regulation and down-regulation by 188Re-liposome, respectively. According to Differentially Expressed MiRNAs in human Cancers (dbDEMC) analysis, most of 188Re-liposome up-regulated microRNAs were categorized as tumor suppressors, while down-regulated microRNAs were oncogenic. The KEGG pathway analysis showed that cancer-related pathways and olfactory and taste transduction accounted for the top pathways affected by 188Re-liposome. 188Re-liposome down-regulated microRNAs, including miR-143, miR-6723, miR-944, and miR-136 were associated with lower survival rates at a high expressive level. 188Re-liposome could suppress the HPC tumors in vivo, and the therapeutic efficacy was associated with the deregulation of microRNAs that could be considered as a prognostic factor.