Diquafosol tetrasodium elicits total cholesterol release from rabbit meibomian gland cells via P2Y purinergic receptor signalling.

Diquafosol tetrasodium (DQS), a purinergic P2Y receptor agonist, stimulates secretion of both water and mucins from the conjunctiva into tears. Hence, DQS-containing eye drops have been approved as a therapeutic option for dry eye disease in some Asian countries, including Japan. Recent clinical reports state that instilling DQS-containing eye drops significantly increases the lipid layer thickness in tears.

Novel use of a chemically modified siRNA for robust and sustainable in vivo gene silencing in the retina.

Despite efficient and specific in vitro knockdown, more reliable and convenient methods for in vivo knockdown of target genes remain to be developed particularly for retinal research. Using commercially available and chemically modified siRNA so-called Accell siRNA, we established a novel in vivo gene silencing approach in the rat retina. siRNA designed for knockdown of the house keeping gene Gapdh or four retinal cell type-specific genes (Nefl, Pvalb, Rho and Opn1sw) was injected into the vitreous body, and their retinal mRNA levels were quantified using real-time PCR.

Constitutively activated ALK2 and increased SMAD1/5 cooperatively induce bone morphogenetic protein signaling in fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disorder characterized by congenital malformation of the great toes and by progressive heterotopic bone formation in muscle tissue. Recently, a mutation involving a single amino acid substitution in a bone morphogenetic protein (BMP) type I receptor, ALK2, was identified in patients with FOP. We report here that the identical mutation, R206H, was observed in 19 Japanese patients with sporadic FOP.

Identification of human oral keratinocyte stem/progenitor cells by neurotrophin receptor p75 and the role of neurotrophin/p75 signaling.

This study was undertaken to determine whether human oral keratinocyte stem cells characteristically express higher levels of the low-affinity neurotrophin receptor p75 and to elucidate the function of p75 in oral keratinocytes. Examination of their expression patterns and cell-cycling status in vivo showed that p75 was exclusively expressed in the basal cell layer of both the tips of the papillae and the deep rete ridges. These immunostaining patterns suggest a cluster organization; most p75(+) cells did not actively cycle in vivo.

Porcine corneal epithelial cells consist of high- and low-integrin beta1-expressing populations.

Purpose: Immunohistochemically, all cells in the porcine corneal epithelium, from the superficial to the basal layer, express integrin beta1. Flow cytometric study has shown that they comprise integrin beta1 high-expressing (beta1 2+) and low-expressing (beta1+) populations. This study was undertaken to determine their proliferation characteristics.

Effects of dexamethasone and cyclosporin A on human beta-defensin in corneal epithelial cells.

Human beta-defensins (hBDs), which are mainly expressed in epithelial tissues, may contribute to infection-protective mechanisms in the ocular surface. We examined hBD1 and hBD2 expression in the ocular surface by RT-PCR and immunohistochemistry and studied the effects of immunosuppressive agents on their expression in human corneal epithelial cells in vitro. mRNA expression of hBD1 and hBD2 was confirmed in corneal epithelial cells.

Human amniotic membrane, like corneal epithelial basement membrane, manifests the alpha5 chain of type IV collagen.

Purpose: To reexamine whether the alpha5 chain of type IV (alpha5[IV]) collagen, thought to be absent, is in fact present in human amniotic membrane.

Methods: Cryosections of human amniotic membrane obtained at Cesarean section were immunohistochemically examined for the presence of alpha5(IV), with or without inclusion of the denaturing step. Amniotic membrane was digested with collagenase to release the noncollagenous NC1 domain from the alpha-chain.

The presence of keratin 5 as an IgG Fc binding protein in human corneal epithelium.

Rabbit immunoglobulin G (IgG) binds specifically to the human corneal epithelium. We investigated this phenomenon to identify the binding material in the tissue. Sections of human cornea were immunostained with negative-control grade rabbit IgG, F(ab')(2) (the antigen recognition fragment of IgG yielded by pepsin digestion), and Fc fragments.

The successful culture and autologous transplantation of rabbit oral mucosal epithelial cells on amniotic membrane.

Purpose: To determine the feasibility of using human amniotic membrane (AM) as a substrate for culturing oral epithelial cells and to investigate the possibility of using autologous cultivated oral epithelial cells in ocular surface reconstruction.

Methods: An ocular surface injury was created in one eye of each of eight adult albino rabbits by a lamellar keratectomy, and a conjunctival excision was performed, including and extending 5 mm outside the limbus. Oral mucosal biopsy specimens were obtained from these eight adult albino rabbits and cultivated for 3 weeks on a denuded AM carrier.