scholarly journals Extracellular Pax6 regulates tangential Cajal-Retzius cell migration in the developing mouse neocortex

2018 ◽  
Author(s):  
H. Kaddour ◽  
E. Coppola ◽  
A. A. Di Nardo ◽  
A. Wizenmann ◽  
M. Volovitch ◽  
...  

AbstractThe embryonic mouse cortex displays a striking low caudo-medial and high rostro-lateral graded expression of the homeoprotein transcription factor Pax6, which presents both cell autonomous and direct non-cell autonomous activities. Through the genetic induction of anti-Pax6 single-chain antibody secretion, we have analyzed Pax6 non-cell autonomous activity on the migration of cortical hem- and septum-derived Cajal-Retzius (CR) neurons by live imaging of flat mount developing cerebral cortices. We observed that blocking extracellular Pax6 disrupts tangential CR cell migration patterns. We found a decrease in the distance travelled and changes both in directionality and in the depth at which CR cells migrate. Tracking of single CR cells in mutant cortices revealed that extracellular Pax6 neutralization enhances or reduces contact repulsion in medial and lateral regions, respectively. This study demonstrates that secreted Pax6 controls neuronal migration thus acting as a bona fide morphogen at an early stage of cerebral cortex development.Summary statementCajal-Retzius cell distribution in the embryonic cortex participates in determining the size and positioning of cortical areas. Here, Kaddour et al. establish that the direct non-cell autonomous activity of the Pax6 transcription factor regulates Cajal-Retzius cell migration.

Biochemistry ◽  
1998 ◽  
Vol 37 (37) ◽  
pp. 13011-13020 ◽  
Author(s):  
Susanne Weber-Bornhauser ◽  
Jolanda Eggenberger ◽  
Ilian Jelesarov ◽  
André Bernard ◽  
Christine Berger ◽  
...  

2020 ◽  
Author(s):  
Raoul Torero-Ibad ◽  
Bilal Mazhar ◽  
Clémentine Vincent ◽  
Clémence Bernard ◽  
Julie Dégardin ◽  
...  

AbstractOTX2 is a homeoprotein transcription factor expressed in photoreceptors and bipolar cells in the retina. OTX2, like many other homeoproteins, transfers between cells and exerts non-cell autonomous effects such as promoting survival of retinal ganglion cells that do not express the protein. Here we used a genetic approach to target extracellular OTX2 in the retina by conditional expression of a secreted single chain anti-OTX2 antibody. Compared to control mice, the expression of this antibody by Parvalbumin-expressing neurons in the retina is followed by a reduction in visual acuity in one-month-old mice with no alteration of the retinal structure or cell type number or aspect. A- and b-waves measured by electroretinogram were also indistinguishable from control mice, suggesting no functional deficit of photoreceptors and bipolar cells. Mice expressing the OTX2-neutralizing antibody did show a significant doubling in the flicker amplitude, consistent with a change in inner retinal function. Our results show that interfering in vivo with OTX2 non-cell autonomous activity in the postnatal retina leads to an alteration in inner retinal cell functions and causes a deficit in visual acuity.Significance statementOTX2 is a homeoprotein transcription factor expressed in retinal photoreceptors and bipolar cells. Although the Otx2 locus is silent in the inner retina, the protein is detected in cells of the ganglion cell layer consistent with the ability of this class of proteins to transfer between cells. We expressed a secreted single chain antibody (scFv) against OTX2 in the retina to neutralize extracellular OTX2. Antibody expression leads to reduced visual acuity with no change in retinal structure, or photoreceptor or bipolar physiology; however, activity in the inner retina was altered. Thus, interfering with OTX2 non-cell autonomous activity in postnatal retina alters inner retinal function and causes vision loss, highlighting the physiological value of homeoprotein direct non-cell autonomous signaling.


2016 ◽  
Vol 477 (4) ◽  
pp. 814-819 ◽  
Author(s):  
Kouhei Hayashi ◽  
Tatsuya Ikari ◽  
Goro Sugiyama ◽  
Tsuyoshi Sugiura ◽  
Yukiko Ohyama ◽  
...  

Author(s):  
Linda C. Hassinger ◽  
James E. Crandall

We have begun to look directly at small numbers of afferent axons to early generated neurons that form the preplate in the developing mouse cortex. The carbocyanine dye Dil (1’1, dioctadecyl-3,3,3’3’-tetramethyl-indocarbocyanine) has proved especially useful for this goal. DiI labels axons and their terminals with greater sensitivity and without some of the disadvantages of axon filling with HRP. The increased sensitivity provided by labeling embryonic axons with DiI has given us new insights into the development of cortical afferents. For instance, we reported originally that afferents from the thalamus were present below the cortex as early as embryonic day 15 (E15) based on HRP injections into mouse embryos. By using DiI placements into the thalamus in aldehyde-fixed brains, we now know that thalamic fibers reach the cortex 24 hrs earlier.


2019 ◽  
Vol 19 (5) ◽  
pp. 610-619 ◽  
Author(s):  
Xue-Qing Zhang ◽  
Lu-Ting Yu ◽  
Pei Du ◽  
Tian-Qi Yin ◽  
Zhi-Yuan Zhang ◽  
...  

Background:Regenerating islet-derived gene family member 4 (Reg4), a well-investigated growth factor in the regenerative pancreas, has recently been reported to be highly associated with a majority of gastrointestinal cancers. Pathological hyper-expression or artificial over-expression of Reg4 causes acceleration of tumor growth, migration, and resistance to chemotherapeutic 5-Fluorouracil (5-FU). Until now, no method has been successfully established for eliminating the effects of Reg4 protein.Methods:This study reports the production of an engineered immunoglobin, a single-chain variable fragment (scFv-Reg4), to specifically bind Reg4 and block the bioactivity. The complementary-determining regions (CDRs) against Reg4 were assigned using MOE and ZDOCK servers. The binding affinity (KD) was determined by bio-layer interferometry (BLI). MKN45 and AGS cell proliferation was determined by Thiazolyl blue tetrazolium bromide (MTT) method and the cell apoptosis was detected by flow cytometry assay.Results:The KD of scFv-Reg4 to Reg4 was determined to be 1.91×10-8. In MKN45 and AGS cell lines, scFv- Reg4 depressed Reg4-stimulated cell proliferation and the inhibitory rates were 27.7±1.5% and 17.3±2.6%, respectively. Furthermore, scFv significantly enhanced 5-FU-induced cell death, from 23.0±1.0% to 28.4±1.2% in MKN45 and 28.2±0.7% to 36.6±0.6% in AGS cells. Treatment with scFv alone could lyse cancer cells to a certain extent, but no significance has been observed.Conclusion:The single-chain antibody (scFv-Reg4) significantly inhibited gastric cancer cell proliferation and synergistically enhanced the lethal effect of 5-FU. Thus, traditional chemo-/radio- therapeutics supplemented with scFv-Reg4 may provide advances in the strategy for gastrointestinal cancer treatment.


1999 ◽  
Vol 271 (3) ◽  
pp. 143-146 ◽  
Author(s):  
Stephen Cooke ◽  
Grace Grant ◽  
Clare McLauchlan ◽  
R.Beau Lotto ◽  
David J. Price

2021 ◽  
Vol 124 ◽  
pp. 112086
Author(s):  
Ghazal Farahavar ◽  
Samira Sadat Abolmaali ◽  
Foroogh Nejatollahi ◽  
Amin Safaie ◽  
Sanaz Javanmardi ◽  
...  

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1494
Author(s):  
Ivan K. Baykov ◽  
Pavel Y. Desyukevich ◽  
Ekaterina E. Mikhaylova ◽  
Olga M. Kurchenko ◽  
Nina V. Tikunova

Tick-borne encephalitis virus (TBEV) causes 5−7 thousand cases of human meningitis and encephalitis annually. The neutralizing and protective antibody ch14D5 is a potential therapeutic agent. This antibody exhibits a high affinity for binding with the D3 domain of the glycoprotein E of the Far Eastern subtype of the virus, but a lower affinity for the D3 domains of the Siberian and European subtypes. In this study, a 2.2-fold increase in the affinity of single-chain antibody sc14D5 to D3 proteins of the Siberian and European subtypes of the virus was achieved using rational design and computational modeling. This improvement can be further enhanced in the case of the bivalent binding of the full-length chimeric antibody containing the identified mutation.


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