GSK-3 Activity Is Critical for the Orientation of the Cortical Microtubules and the Dorsoventral Axis Determination in Zebrafish Embryos

The formation of dorsal-ventral (D–V) axis is the earliest event that breaks the radial symmetry and determines the bilateral body plan of a vertebrate embryo, however, the maternal control of this process is not fully understood. Here, we discovered a new dorsalizing window of acute lithium treatment, which covers only less than 10 minutes after fertilization. Lithium treatment in this window was not able to reverse the ventralized phenotype in tokkeabi (tkk) mutant embryos, and its dorsalizing activity on wild-type embryos was inhibited by nocodazole co-treatment. These evidences indicate that the underlying mechanism is independent of a direct activation of Wnt/β-catenin signaling, but depends on the upstream level of the microtubule mediated dorsal determinant transport. In order to identify the target of lithium in this newly discovered sensitive window, GSK-3 inhibitor IX as well as the IMPase inhibitor L690, 330 treatments were performed. We found that only GSK-3 inhibitor IX treatment mimicked the lithium treatment in the dorsalizing activity. Further study showed that the parallel pattern of cortical microtubules in the vegetal pole region and the directed migration of the Wnt8a mRNA were randomized by either lithium or GSK-3 inhibitor IX treatment. These results thus revealed an early and critical role of GSK-3 activity that regulates the orientation of the cortical microtubules and the directed transport of the dorsal determinants in zebrafish embryos

Light-Driven Synthetic Biology: Progress in Research and Industrialization of Cyanobacterial Cell Factory

Light-driven synthetic biology refers to an autotrophic microorganisms-based research platform that remodels microbial metabolism through synthetic biology and directly converts light energy into bio-based chemicals. This technology can help achieve the goal of carbon neutrality while promoting green production. Cyanobacteria are photosynthetic microorganisms that use light and CO2 for growth and production. They thus possess unique advantages as “autotrophic cell factories”. Various fuels and chemicals have been synthesized by cyanobacteria, indicating their important roles in research and industrial application. This review summarized the progresses and remaining challenges in light-driven cyanobacterial cell factory. The choice of chassis cells, strategies used in metabolic engineering, and the methods for high-value CO2 utilization will be discussed

The effects of different shapes of capsulorrhexis on postoperative refractive outcomes and the effective position of the intraocular lens in cataract surgery

Abstract Background To evaluate the effects of anterior capsular opening size on deviation from predicted refraction and the effective position of the intraocular lens (ELP) in cataract surgery. Methods Nonrandomized clinical trial. Eighty patients (80 eyes) with simple age-related cataracts were treated from May 2018 to September 2018 at the Fourth Affiliated Hospital of China Medical University. All patients undergoing phacoemulsification received intraocular lens based on the voluntary principle. Forty eyes were implanted with the C-loop haptic intraocular lens (AMO Tecnis ZCB00) while the other 40 eyes were implanted with the plate haptic intraocular lens (CT ASPHINA 509 M). Follow-up visits were conducted postoperatively at 1 week, 1 month, and 3 months during which patients underwent refraction and data collection after pupil dilation, which included anterior segment photography and Scheimpflug imaging by Pentacam. The area, horizontal and vertical diameter of the capsulorrhexis, circularity, decentration, and package were analysed using the image analysis software Image-Pro-Plus 6.0,then evaluated the relationship between the different shapes of capsulorrhexis with deviation from predicted refraction and ELP in cataract surgery. Results Deviation from predicted refraction and all of the parameters of capsulorrhexis were not correlative in the 509 M IOL group, however, in the Tecnis IOL group, while the deviation from predicted refraction and all of the capsulorrhexis parameters were not correlative at 1 week, the deviation from predicted refraction did correlate with capsulorrhexis area, horizontal diameter at 1 month (P = 0.029, P = 0.048), and with capsulorrhexis area, vertical diameter at 3 months (P = 0.03, P = 0.017). The ELP correlated with package in both groups postoperatively (r > 0, P  0.05). For the Tecnis IOL group, the ELP and capsulorrhexis area were correlated at 1 week and 1 month, while the ELP and horizontal diameter, the ELP and vertical diameter were correlated at 1 week, but did not correlate with the other capsulorrhexis parameters in the Tecnis IOL group (all P > 0.05). Conclusions The shape of the capsulorrhexis has an effect on postoperative refractive outcomes and the effective position of the intraocular lens in cataract surgery, and plate haptic intraocular lenses have better refractive stability than C-loop haptic intraocular lenses. Trial registration ChiCTR1800015638,2018-04-12

0-mpf nocodazole treatment reverses the dorsalizing effect of the 0-mpf lithium treatment.

<p>The 0-mpf embryos were treated with 0.35 M LiCl solution in the absence or presence of 0.1 μM nocodazole for 5 min, and then observed at 12 hpf and 22 hpf. 0 35 M NaCl treatment served as control. (A and E) 0-mpf NaCl treated embryos at 12 hpf (A) and 22 hpf (E). (B and F) 0-mpf NaCl and nocodazole co-treated embryos at 12 hpf (B) and 22 hpf (F). (C and G) 0-mpf lithium treated embryos at 12 hpf (C) and 22 hpf (G). (D and H) 0-mpf lithium and nocodazole co-treated embryos at 12 hpf (D) and 22 hpf (H). (I) Statistical data were obtained at 12 hpf for the experiment with embryo numbers on the top of each column.</p

Paclitaxel treatment on wild-type and <i>tkk</i> mutant embryos.

<p>(A) Dorsal view of an untreated 12 hpf embryo. (B) Dorsal view of a 0-mpf paclitaxel treated embryo with ventralized phenotype. (C) An embryo with normal phenotype. (D) An embryo with CE defect like phenotype, showing a smaller head, shorter anterior-posterior axis and malformed somites. (E) A ventralized embryo. Embryos in (C-E) were observed at 24 hpf. The statistical data based on the 24 hpf observation were shown in (F) with embryo numbers shown on the top of each column.</p

Comparison between lithium and chemical inhibitors of GSK-3 or IMPase in the dorsalizing activity.

<p>(A–L) Phenotypic comparison of NaCl, lithium and GSK-3 inhibitor IX exposures. (M–X) Phenotypic comparison of NaCl, lithium and L690, 330 injections. Embryos in A-X were observed at stages indicated at the left side of the figure. (Y) Statistical data of the phenotypic analysis at 11.5 hpf with embryo numbers on the top of each column. (Za–Zf) Examination of <i>gsc</i> expression in 0-mpf NaCl, LiCl, GSK-3 inhibitor IX and L690,330 exposed (Za–Zc) or injected embryos (Zd–Zf).</p

Model of dorsal-ventral axis formation in zebrafish.

<p>The zebrafish DV axis specification can be divided to four phases based on the dynamic alteration of the dorsalizing activity of lithium treatment. SW1 designates 0–10 mpf in which lithium treatment can cause dorsalization of the embryos. In this phase, fertilization initiates a GSK-3 dependent mechanism regulating the orientation but not stablization of vegetal microtubules which is critical for the dorsalward transport of DDs like <i>Wnt8a</i> mRNA. UW1 designates the first unresponsive window of lithium treatment, from 10 mpf to the 32-cell stage, in which, especially in the early period, lithium treatment fails to efficiently cause dorsalization. In this period, dorsal determinants are transported from the vegetal pole to the perspective dorsal side. The transduction of Wnt/β-catenin pathway is probably blocked by some unknown mechanism in SW1 and UW1. SW2 designates the period from the 32-cell stage to the mid-blastula stage. In this period, dorsally located DDs are able to inhibit GSK-3, causing the stabilization and nuclear localization of β-catenin, and lead to the expression of dorsal organizer genes. In UW2, lithium treatment loses its ability to dorsalize zebrafish embryos and the organizer gene expression is translated gradually by cell movement to morphologically distinguished dorsal-ventral axis. Arrow head at the lower-left corner indicates the shield.</p

The comparison of dorsal and ventral gene expression between 0-mpf lithium treatment and 32-cell-stage lithium treatment.

<p>Representative embryos from indicated groups stained by <i>gsc</i> probe (A–C, and G–I) or <i>eve1</i> probe (D–F and J–L) at 50% epiboly. All the embryos are animal pole view and with dorsal side upward if it can be distinguished.</p

The dorsalizing activity of lithium treatment during zebrafish early development.

<p>(A) A severely dorsalized embryo (radialized). (B) A mildly dorsalized embryo. (C) A normal embryo. (D) Diagram demonstrating the dynamics of the dorsalizing capability of acute lithium treatment (0.3 M LiCl for 8 min). The abscissa axis designates the time at which lithium treatment began. The ordinate axis designates the percentage of three kinds of embryos with different degrees of dorsalization at 12.5 hpf. SW1: Sensitive Window 1; SW2: Sensitive Window 2; UW: Unresponsive Window. The data were obtained in three or more separate experiments, and the number of the embryos used for each data set is more than 100. (E) The dorsalizing effect of the lithium treatment is not caused by osmotic stress by comparing with NaCl treatment at the same salt concentration and treatment time. Embryos in A, B, C and E was at 12.5 hpf, and lateral viewed. The bar in A represents 500 μm.</p