Whether LIF contributes to differentiation inhibition in rab

Whether LIF contributes to differentiation inhibition in rabbit PSCs is unclear. LIF and FGF2 cooperatively support self-renewal in ESCs derived from parthenogenotes and propagated in feeder-free conditions, but the effect of LIF is modest (Hsieh et al., 2011). In this study, AKSL and AKSgff cell lines exhibited similar growth parameters, cell-cycle features, and transcriptomes. Moreover, neither withdrawal of LIF nor JAK inhibition resulted in observable differentiation, suggesting that LIF/JAK signaling in the presence of feeders is dispensable for self-renewal in rbESCs. However, the AKSL line was more efficient at colonizing the epiblast of the rabbit embryo, suggesting a more immature phenotype.
Experimental Procedures All the procedures used in the study followed the national and European regulations concerning animal experiments, and were approved by the authorized national and veterinary agencies. A detailed description of the procedures is provided in Supplemental Experimental Procedures.
Author Contributions
Acknowledgments We thank Anaïs Vitorino Carvalho for microarray probe annotation. This study was supported by research grants from the Agence Nationale de la Recherche (ANR; projects PLURABBIT no. PCS-09-GENM-08 and ORYCTOGENE no. ANR-12-RPIB-0013), European Cooperation in Science and Technology (COST) Action (Rabbit Genome Biology [RGB]-Net no. TD1101), HyPharm, Région Rhône-Alpes (ADR CIBLE 2010 project no. R10065CC to Y.T.), Infrastructure Nationale en Biologie et Santé INGESTEM (ANR-11-INBS-0009), Infrastructure Nationale en Biologie et Santé CRB-Anim (ANR-11-INBS-0003), IHU-B CESAME (ANR-10-IHUB-003), LabEx DEVweCAN (ANR-10-LABX-0061), LabEx CORTEX (ANR-11-LABX-0042) of the University of Lyon within the program Investissements d’Avenir (ANR-11-IDEX-0007), and Fondation pour la Recherche Médicale (FRM SPE20140129375) to P.O. The authors would like to thank Enago (www.enago.com) for the English language review.
Introduction The holocrine meibomian glands are embedded in the eyelid tarsal plate and secrete lipid (meibum) onto the ocular surface tear film to reduce aqueous tear buy HOAt and evaporative stress. Meibomian gland atrophy and hyposecretion of meibum has been linked to the development of evaporative dry eye, which is a common age-related, ocular surface disorder that can seriously impair vision (Horwath-Winter et al., 2003; Lemp et al., 2012). Meibum is synthesized by enlarged, terminally differentiated meibocytes that form the acini of the meibomian gland, and is delivered through the central duct to the mucocutaneous junction of the eyelid margin. The mechanism that explains how the acinar and ductal epithelia renew throughout life has not been well described, and there is only limited information about a putative meibomian gland stem cell population (Knop et al., 2011; Olami et al., 2001; Parfitt et al., 2015). Meibomian glands share similar characteristics with the sebum-producing sebaceous glands adjoined to hair follicles, as they are developmentally similar skin appendages with comparable keratin-expression profiles (Knop et al., 2011). For example, all basal epithelial cells of the developing (Call et al., 2016) and adult mouse meibomian gland (Parfitt et al., 2013) exhibit type I (acidic) keratin 14 (K14), which heterodimerizes with type II (basic) keratin 5 (K5) to form the intermediate filaments that constitute their cytoskeleton. As in sebaceous glands, basal acinar cells of the meibomian gland differentiate and move centripetally toward the center of an acinus before lipogenesis and holocrine secretion. These terminally differentiated meibocytes synthesize and accumulate lipid, express high levels of peroxisome proliferator-activated receptor gamma (PPAR-γ), and undergo cell degeneration and disintegration of the cell membrane and nuclear material (pyknosis). This lifelong differentiation and destruction of acinar cells requires continual turnover of the basal layer and suggests the presence of a proximal stem cell reservoir to provide long-term self-renewal, as is the case with other epithelial tissues such as the hair follicle (Cotsarelis et al., 1990; Tumbar et al., 2004), corneal epithelium (Cotsarelis et al., 1989; Di Girolamo et al., 2015; Stepp and Zieske, 2005), and intestine (Barker et al., 2007; Pinto and Clevers, 2005). Therefore, characterizing meibomian gland progenitors may provide important insights into holocrine tissue regeneration and dysfunction, as it has recently been shown that the meibomian gland hyperproliferates in response to environmental evaporative stress (Suhalim et al., 2014), while aging in both humans and mice results in hypoproliferation and atrophic changes (Nien et al., 2009, 2011; Parfitt et al., 2013).