Human ESC-Derived Neural Crest Model Reveals a Key Role for SOX2 in Sensory Neurogenesis

The transcription factor SOX2 is widely known to play a critical role in the central nervous system; however, its role in peripheral neurogenesis remains poorly understood. We recently developed an hESC-based model in which migratory cells undergo epithelial to mesenchymal transition (EMT) to acquire properties of neural crest (NC) cells. In this model, we found that migratory NC progenitors downregulate SOX2, but then start re-expressing SOX2 as they differentiate to form neurogenic dorsal root ganglion (DRG)-like clusters. SOX2 downregulation was sufficient to induce EMT and resulted in massive apoptosis when neuronal differentiation was induced. In vivo, downregulation of SOX2 in chick and mouse NC cells significantly reduced the numbers of neurons within DRG. We found that SOX2 binds directly to NGN1 and MASH1 promoters and is required for their expression. Our data suggest that SOX2 plays a key role for NGN1-dependent acquisition of neuronal fates in sensory ganglia

Derivation of hair-inducing cell from human pluripotent stem cells.

Dermal Papillae (DP) is a unique population of mesenchymal cells that was shown to regulate hair follicle formation and growth cycle. During development most DP cells are derived from mesoderm, however, functionally equivalent DP cells of cephalic hairs originate from Neural Crest (NC). Here we directed human embryonic stem cells (hESCs) to generate first NC cells and then hair-inducing DP-like cells in culture. We showed that hESC-derived DP-like cells (hESC-DPs) express markers typically found in adult human DP cells (e.g., p-75, nestin, versican, SMA, alkaline phosphatase) and are able to induce hair follicle formation when transplanted under the skin of immunodeficient NUDE mice. Engineered to express GFP, hESC-derived DP-like cells incorporate into DP of newly formed hair follicles and express appropriate markers. We demonstrated that BMP signaling is critical for hESC-DP derivation since BMP inhibitor dorsomorphin completely eliminated hair-inducing activity from hESC-DP cultures. DP cells were proposed as the cell-based treatment for hair loss diseases. Unfortunately human DP cells are not suitable for this purpose because they cannot be obtained in necessary amounts and rapidly loose their ability to induce hair follicle formation when cultured. In this context derivation of functional hESC-DP cells capable of inducing a robust hair growth for the first time shown here can become an important finding for the biomedical science

Real time Q-PCR primers.

<p>Real time Q-PCR primers.</p

Role of BMP signaling in DP cell fate acquisition.

<p>(A) Morphology and transplantation outcomes of hESC-DP cells derived in the absence or in the presence of selective BMP inhibitor dorsomorphin. (B) Q-PCR analysis of expression of Versican, Corin, Nexin-1, p-75, Vimentin and SMA in hESC-DP cells in the absence or in the presence of selective BMP inhibitor dorsomorphin. All data are presented as mean ± SEM and were analyzed with Student’s t-test. *, P ≤ 0.05; **, P ≤ 0,001. Scale bars 50μm for cell cultures and 0.5 mm for cell transplantations.</p

Subcutaneous transplantations of GFP-labeled hESC-DPs and hIPSC-DPs.

<p>(A) Stereoscopic observation of the whole mount transplants identified GFP-positive hESC-DP cells in positions of DP (arrows heads) and dermal capsule (arrows) in the newly formed hairs; insets show 2x enlargements of the DP regions. (B) GFP-labeled hIPSC-DPs can be found in DP and dermal capsule of the hairs: whole mount transplants (GFP/bright field) and 8um sections (bright field). Inset, fluorescence image of GFP-positive cells in the DP area of hair follicle (2x enlargement of the white square of DP area in the bright field image). (C, D) GFP-positive DPs of newly formed hairs (GFP/bright field, confocal microscopy) are positive for Versican (Versican, confocal microscopy) and Alkaline Phosphatase (AP, bright field)). (E) Rarely (~1% of newly formed hairs) NC-derived GFP-positive cells were detected in the outer root sheath area (arrows) as well as GFP-positive DP (outlined). Confocal image in the GFP panel. (F) NC-derived GFP-positive cells were found in hair matrix in transplants (confocal microscopy). Inset shows 2x enlargement of GFP-positive cells; GFP in white. Note multiple melanin granules (in black) present throughout GFP-positive cells. Scale bars 250μm for A; 50 μm for B-F.</p

Differentiation of hESCs into DP-like cells via NC intermediate.

<p>(A) Schematic representation of the differentiation strategy. (B) Expression of migratory NC markers Sox 10 and Foxd3, in hESC-NC cultures. Immunofluorescent staining, DAPI in blue. (C) Flow cytometry analysis of NC marker integrin alpha-4 (ITGA4) and hESC markers OCT4 and SSEA4 in hESC-NC cultures. (D) Expression of p-75, Nestin, Versican, SMA and Alkaline Phosphatase (AP) in hESC-NC, hDP (from normal skin) and hESC-DP cultures. Immunofluorescent staining, DAPI in blue. (E) Q-PCR analysis of hDP markers p-75, Nexin-1, Versican, SMA and Vimentin in hESC-DP cultures during DP patterning. Day 0 = hESC-NC cells. Levels of gene expression, shown as log of fold change over hESC-NC levels, were normalized to 18S. For each gene the dashed line represents levels of gene expression in hDP cell cultures. Scale bars 100 μm.</p

Large-scale annotated dataset for cochlear hair cell detection and classification

Our sense of hearing is mediated by cochlear hair cells, localized within the sensory epithelium called the organ of Corti. There are two types of hair cells in the cochlea, which are organized in one row of inner hair cells and three rows of outer hair cells. Each cochlea contains a few thousands of hair cells, and their survival is essential for our perception of sound because they are terminally differentiated and do not regenerate after insult. It is often desirable in hearing research to quantify the number of hair cells within cochlear samples, in both pathological conditions, and in response to treatment. However, the sheer number of cells along the cochlea makes manual quantification impractical. Machine learning can be used to overcome this challenge by automating the quantification process but requires a vast and diverse dataset for effective training. In this study, we present a large collection of annotated cochlear hair-cell datasets, labeled with commonly used hair-cell markers and imaged using various fluorescence microscopy techniques. The collection includes samples from mouse, human, pig and guinea pig cochlear tissue, from normal conditions and following in-vivo and in-vitro ototoxic drug application. The dataset includes over 90,000 hair cells, all of which have been manually identified and annotated as one of two cell types: inner hair cells and outer hair cells. This dataset is the result of a collaborative effort from multiple laboratories and has been carefully curated to represent a variety of imaging techniques. With suggested usage parameters and a well-described annotation procedure, this collection can facilitate the development of generalizable cochlear hair cell detection models or serve as a starting point for fine-tuning models for other analysis tasks. By providing this dataset, we aim to supply other groups within the hearing research community with the opportunity to develop their own tools with which to analyze cochlear imaging data more fully, accurately, and with greater ease

Large-scale annotated dataset for cochlear hair cell detection and classification

&lt;p&gt;Our sense of hearing is mediated by cochlear hair cells, of which there are two types organized in one row of inner hair cells and three rows of outer hair cells. Each cochlea contains 5 - 15 thousand terminally differentiated hair cells, and their survival is essential for hearing as they do not regenerate after insult. It is often desirable in hearing research to quantify the number of hair cells within cochlear samples, in both pathological conditions, and in response to treatment. Machine learning can be used to automate the quantification process but requires a vast and diverse dataset for effective training. In this study, we present a large collection of annotated cochlear hair-cell datasets, labeled with commonly used hair-cell markers and imaged using various fluorescence microscopy techniques. The collection includes samples from mouse, rat, guinea pig, pig, primate, and human cochlear tissue, from normal conditions and following &lt;i&gt;in-vivo&lt;/i&gt; and &lt;i&gt;in-vitro&lt;/i&gt;ototoxic drug application. The dataset includes over 107,000 hair cells which have been manually identified and annotated as either inner or outer hair cells. This dataset is the result of a collaborative effort from multiple laboratories and has been carefully curated to represent a variety of imaging techniques. With suggested usage parameters and a well-described annotation procedure, this collection can facilitate the development of generalizable cochlear hair-cell detection models or serve as a starting point for fine-tuning models for other analysis tasks. By providing this dataset, we aim to give other hearing research groups the opportunity to develop their own tools with which to analyze cochlear imaging data more fully, accurately, and with greater ease.&nbsp;&lt;/p&gt;&lt;p&gt;Associated code is provided here: https://github.com/indzhykulianlab/hcat-data&lt;/p&gt