Distribution of spiny neurons in the <i>Xenopus</i> tadpole brain.

<p>Fluorescent dye was electroporated into neurons located in different brain regions. (A1, A2) Spiny neuron in the OB. (A1) Electrode filled with fluorescent dye inserted into the OB, pointing to a labeled neuron. (A2) High magnification of the neuron in A1. Inset shows spines on a dendrite. (B1, B2) Mitral cell in the anterior OB. (C1, C2) Spiny neuron in the telencephalon (Tel). (D1, D2) Non-spiny neuron in the tectum (Tec). (E) Diagram summarizing all labeled spiny (red) and non-spiny (blue) neurons in different brain areas in the left hemisphere. Twenty neurons randomly labeled in the optic tectum were non-spiny neurons; 69 neurons in the OB and telencephalon were spiny neurons except for 11 neurons.</p

Transformation of dendritic protrusions into other spine types.

<p>(A) A mushroom spine (indicated by an arrow in A1) transformed into a thin spine at 30 min (A3), and reverted to a mushroom spine at 60 min (A5). Another thin spine (indicated by an arrowhead) transformed into a mushroom spine at 30 min (A3). (B) A stubby spine (indicated by an arrow in B1) transformed into a mushroom spine at 2 h (B2), remained in that shape up to 6 h (B4), and became a thin spine at 24 h (B5). “+” indicates newly added spines, and “-” indicates eliminated spines. (C) The percentage of spines that transformed into other forms during the pooled data of 15-min and 2-h interval observations. (D–G) Percentage of each spine type that transformed into other types. (D) All filopodia transformed into thin spines, and a few transformed into large spines (<i>P</i> < 0.05). (E) Some changed thin spines transformed into filopodia, and some transformed into large spines; no significant difference was observed between these two forms. (F) Most of the stubby spines transformed into mushroom spines, and only a few transformed into small spines (<i>P</i> < 0.001). (G) Most of the mushroom spines transformed into stubby spines, and only a few transformed into small spines (<i>P</i> < 0.05). Figure labels: trans. = transformation, fil. = filopodia, stu. = stubby, and mus. = mushroom. Neurons used for transformation analysis were from the 15-min short-term and 2-h middle-term observations. Bars indicate means ± SEM. Significance was set at *<i>P</i> < 0.05, **<i>P</i> < 0.01, and ***<i>P</i> < 0.001.</p

<i>In vivo</i> images of DsRed2 and PSD95-GFP double-labeled spiny neurons in <i>X</i>. <i>laevis</i> tadpoles.

<p>(A) A spiny neuron was labeled by DsRed2 and PSD95-GFP. The postsynaptic specializations on spines are shown as yellow puncta. Green dots are developing melanocyte pigmentation not fully inhibited by phenylthiocarbamide (PTU). (B, C) High magnification views showing the different types of dendritic spines of the spiny neuron in (A). F: filopodia; T: thin spine; S: stubby spine; M: mushroom spine. The yellow puncta represent synaptic contacts, most of which were on stubby and mushroom spines. (D) Statistical analysis of the percentage of PSD95-GFP on different types of dendritic spines. Stubby and mushroom spines exhibited a higher number of PSD95-GFP puncta than filopodia and thin spines. Bars indicate mean ± SEM. N = 4 neurons with 9 dendrites were used for colocalization analysis of PSD95-GFP. The significance levels were*<i>P</i> < 0.05, **<i>P</i> < 0.01, and ***<i>P</i> < 0.001.</p

Stability and dynamics of dendritic spines during short-term observation.

<p>(A) Serial time-lapse images of a single neuron showing stable spines (filled arrowheads) and dynamic spines (open arrowheads) at 15-min intervals. (B) Stability of the 4 types of dendritic spines was observed at 15-min intervals. The stubby and mushroom spines were more stable than the filopodia and thin spines. (C) Detailed analysis of the stability of filopodia and thin spines versus stubby and mushroom spines at each 15-min interval observation. (D, E) Detailed analysis of filopodia and thin spines versus stubby and mushroom spines that were added (D) or eliminated (E) during each 15-min interval observation. (F) Average dendritic spine stability and dynamics at each 15-min observation. Bars indicate means ± SEM. N = 4 neurons with 9 dendrites were used for the 15-min short-term observation. Significance was set at *<i>P</i> < 0.05, **<i>P</i> < 0.01, and ***<i>P</i> < 0.001.</p

Suppression of cancer stemness by upregulating Ligand-of-Numb protein X1 in colorectal carcinoma

<div><p>Cancer stem-like cells (CSCs) have been reported to play major roles in tumorigenesis, tumor relapse, and metastasis after therapy against colorectal carcinoma (CRC). Therefore, identification of colorectal CSC regulators could provide promising targets for CRC. Ligand-of-Numb protein X1 (LNX1) is one E3 ubiquitin ligase which mediates the ubiquitination and degradation of Numb. Although several studies indicate LNX1 could be a potential suppressor of cancer diseases, the functions of LNX1 in mediating cancer stemness remain poorly understood. In this study, LNX1 was identified as a negative regulator of cancer stemness in CRC, which was downregulated in colonospheres or side population (SP) cells. Furthermore, the coxsackievirus and adenovirus receptor (CXADR) was found to be one critical downstream mediator of cancer stemness regulated by LNX1. Interestingly, the anti-breast cancer drug tamoxifen was found to be an agonist of LNX1 and suppress cancer stemness in CRC. In sum, this study provided the evidences that LNX1 signaling plays important roles in regulating the stemness of colon cancer cells.</p></div

Effect of LNX1 knockdown on the tumor formation rate using the HT29 cell line.

<p>Effect of LNX1 knockdown on the tumor formation rate using the HT29 cell line.</p

Analysis of the function of LNX1 in mediating cancer stemness in CRC.

<p>(A) Effect of LNX1 knockdown on the percentage of SP. (B) The efficiency of LNX1 knockdown using semi-quantitative RT PCR analysis. (C) Effect of LNX1 knockdown on the capacities of colonosphere formation (n = 8 per group). (D) Effect of LNX1 knockdown on the rates of colonosphere formation (p value was calculated using the online ELDA software). (E) The efficiency of LNX1 knockdown using shLNX1 lentivirus particles. Data from triplicates are presented as the mean±SD, *P<0.05, **P<0.01, ***P<0.001.</p

Analysis of LNX1 and CSC markers in CRC SP and non-SP cells.

<p>(A) Sorting of SP and non-SP cells using BD Aria software. The verapamil group was set as the negative control. (B) and (C) are the western blot and the semi-quantitative RT PCR analysis of genes (LNX1 as well as CSC markers in CRC including LGR5, CD133, ABCB5 and ALDH1A1).</p

Effects of circadian clock protein Per1b on zebrafish visual functions

<p>The circadian clock is an endogenous and entrainable time-keeping mechanism with a period of approximately 24 h, operated by transcription/translation feedback loops composed of circadian clock genes and their proteins. The visual system displays robust circadian changes. Relatively little, however, is known about the mechanisms underlying visual circadian rhythmicity. Zebrafish <i>period1b</i> (<i>per1b</i>), as a canonical circadian clock gene, is involved in circadian regulation. Here, we observed that zebrafish <i>per1b</i> mutants exhibit visual defects including reduced behavioral contrast sensitivity and significant retinal dopaminergic deficiency. Further, partially damaged dopaminergic interplexiform cells in wild-type larvae also led to reduced behavioral contrast sensitivity, while exogenous dopamine administration effectively restored the contrast sensitivity of <i>per1b</i> mutants. Taken together, these results suggest that retinal dopaminergic deficiency derived from loss of per1b results in visual defects in zebrafish.</p> <p><b>Abbreviations:</b> per1b, period1b; per, period; per1, period1; per2, period2; per3, period3; ERG, electroretinogram; DA-IPCs, dopaminergic interplexiform cells; IRBP, interphotoreceptor retinoid binding protein; MS-222, methane-sulfonate; USTC, University of Science and Technology of China; OKR, optokinetic response; dpf, day postfertilization; 6-OHDA, 6-hydroxydopamine; TH, tyrosine hydroxylase; DA, dopaminergic; INL, inner nuclear; IPL, innerplexiform layers; hpf, hours postfertilization; cpd, cycle per degree; ADHD, attention deficit and hyperactivity disorder.</p

Probable mechanisms underlying tamoxifen therapy targeting ER-positive cells against breast cancer.

<p>(A) Effect of ER knockdown on the LNX1 level, data was obtained from the curated Datasets in the Gene Expression Omnibus (GEO) repository(GDS4061). (B) Schematic presentation of the predicted mechanisms underlying tamoxifen therapy targeting ER-positive cells against breast cancer, the broken lines indicate the possible cases at different circumstance. In ER-positive cells, tamoxifen could trigger the expression of LNX1 and exert its anti-tumor function, which could be abolished in ER-negative cells due to the restricted LNX1 level.</p