Multipotent neurogenic fate of mesenchymal stem cell is determined by Cdk4-mediated hypophosphorylation of Smad-STAT3

<p>Cyclin-dependent kinase (Cdk) in complex with a corresponding cyclin plays a pivotal role in neurogenic differentiation. In particular, Cdk4 activity acts as a signaling switch to direct human mesenchymal stem cells (MSCs) to neural transdifferentiation. However, the molecular evidence of how Cdk4 activity converts MSCs to neurogenic lineage remains unknown. Here, we found that Cdk4 inhibition in human MSCs enriches the populations of neural stem and progenitor pools rather than differentiated glial and neuronal cell pools. Interestingly, Cdk4 inhibition directly inactivates Smads and subsequently STAT3 signaling by hypophosphorylation, and both Cdk4 and Smads levels are linked during the processes of neural transdifferentiation and differentiation. In summary, our results provide novel molecular evidence in which Cdk4 inhibition leads to directing human MSCs to a multipotent neurogenic fate by inactivating Smads-STAT3 signaling.</p

Primers used for potential mutations amplification.

<p>Primers used for potential mutations amplification.</p

Fundus photography of the proband and a normal subject.

<p>(A) Attenuation of retinal arterioles, bone-spicule pigmentation in the midperiphery, atrophy of the retinal pigment epithelium, waxy-pale discs, and enlarged optic cups in the fundus of the proband (B) Normal fundus.</p

The <i>SNRNP200</i> sequencing results.

<p>(Top) Sequencing data shows that a C to G transversion (arrow) resulted in the substitution of glutamine-885 by glutamic acid (Q885E) in affected individuals. (Bottom) The corresponding normal sequence (arrow) was found in unaffected family members and controls.</p

Clinical features of patients with the <i>SNRNP200</i> mutation.

<p>F: female; M: male; BCVA: best corrected visual acuity; logMAR: logarithm of the Minimum Angle of Resolution; NL: no light perception; IOP: intraocular pressure; PSC: posterior subcapsular cataract; ERG: electroretinography; NR: not recordable; Int: intensive Diff: diffuse; NA: not available.</p

Structure modeling of hBrr2(477–1174).

<p>(A) Orthogonal ribbon plots of the model of hBrr2(477–1174). Three conserved residues (Q885, S1087 and R1090) that may interact with RNA base are shown as space-filling spheres, and colored as wheat, red and yellow respectively. (B) Orthogonal ribbon plots of the Hel308 DNA helicase <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0045464#pone.0045464-Berson1" target="_blank">[2]</a> (PDB ID: 2p6r). Cyan, Hel308; pink, DNA. Three DNA interacting residues R388, T596 and W599 in Hel308 which correlate to Q885, S1087 and R1090 in human respectively are shown as space-filling spheres, and colored in order as wheat, red and yellow. (C) A close view of the central pore in the model, highlighting the three conserved residues (Q885, S1087 and R1090). (D) A close view of the path of DNA strand through the central pore, highlighting the three related residues (R388, T596 and W599) implicated in DNA binding.</p

Multiple sequence alignment of <i>SNRNP200</i>.

<p>Sequence alignment of hBrr2 from eight species is shown. Q885E occurs at a highly conserved position in hBrr2 (arrow).</p

Yeast replicative lifespan and terminal morphology in culture media of varying pH

<p>The replicative lifespan of yeast (BY4742 strain background) cultured in media of varying pH. Column L (“lifespans”; LS) through AE represent the number of daughter cells produced by each mother cell and the endCode (column AF-AY) represents the terminal morphology of the corresponding numbered mother cell. End lost represents the number of cells that did not receive a terminal cell morphology designation. U = unbudded, S = small bud (<50% size of mother), L = large bud (>=50% size of mother), C = cluster of cells.</p

Representative Pictures from the Laboratory Section of the Course

<p>Representative Pictures from the Laboratory Section of the Course</p

Discovery-Based Science Education: Functional Genomic Dissection in Drosophila by Undergraduate Researchers

Discovery-Based Science Education: Functional Genomic Dissection in Drosophila by Undergraduate Researcher