Tissue engineered ultra-thin descemet stripping corneal endothelial layers using porcine cornea and stem cells.

Due to their very poor proliferative capacity, the dysfunction of corneal endothelial cells can sometimes lead to incurable eye diseases that require corneal transplantation. Although many studies have been performed to reconstruct corneal endothelial cells, corneal transplantation is still considered to be the established approach. In this study, we developed bio-engineered Descemet stripping endothelial (DSE) layers, using porcine cornea and induced pluripotent stem cell (iPSC)-derived corneal endothelial cells (iCECs). First, we optimized a protocol to prepare an ultra-thin and decellularized Descemet stripping (DS) scaffold from porcine cornea. Our DS layers show over 90% transparency compared to the control. Porcine-derived cells and xenogenic antigens disappeared, whereas the collagen matrix remained in the graft. Next, corneal endothelial cell lines or iCECs were seeded on the decellularized DS graft and cultured for 7 days. The drying method reduced graft rolling and edema, and increased transparency during culture. The reseeded cells were evenly distributed over the graft, and most of the cells survived. Although future clinical studies are warranted, engineered DSE tissues using xenogenic tissues and stem cells will be useful tools for the treatment of incurable corneal diseases.

Improvement of cognitive function and physical activity of aging mice by human neural stem cells over-expressing choline acetyltransferase.

Aging is characterized by progressive loss of cognitive and memory functions as well as decrease in physical activities. In the present study, a human neural stem cell line (F3 NSC) over-expressing choline acetyltransferase (F3.ChAT), an enzyme responsible for acetylcholine synthesis, was generated and transplanted in the brain of 18-month-old male ICR mice. Four weeks post-transplantation, neurobehavioral functions, expression of ChAT enzyme, production of acetylcholine and neurotrophic factors, and expression of cholinergic nervous system markers in transplanted animals were investigated. F3.ChAT NSCs markedly improved both the cognitive function and physical activity of aging animals, in parallel with the elevation of brain acetylcholine level. Transplanted F3 and F3.ChAT cells were found to differentiate into neurons and astrocytes, and to produce ChAT proteins. Transplantation of the stem cells increased brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), enhanced expression of Trk B, and restored host microtubule-associated protein 2 and cholinergic nervous system. The results demonstrate that human NSCs over-expressing ChAT improve cognitive function and physical activity of aging mice, not only by producing ACh directly but also by restoring cholinergic neuronal integrity, which might be mediated by neurotrophins BDNF and NGF.

What is your diagnosis? Ascites fluid from an 11-year-old dog with epigastric bulging.

An 11-year-old, intact female, Yorkshire Terrier dog was presented with epigastric bulging. Results of a CBC included mild neutrophilia and thrombocytopenia. Radiographic examination and abdominal ultrasonography revealed abundant ascites and a well-circumscribed mass in the caudal region of the spleen. Abdominocentesis revealed bloody fluid. Cytologic analysis of the fluid revealed numerous clustered and individual large cells with moderate anisocytosis and anisokaryosis. The spleen was surgically resected. An imprint smear of a white nodular tumor on the caudal pole of the spleen contained a bimorphic population of small and large lymphocytes. The cytologic diagnosis was lymphoma. Histologically, large lymphocytes with distinct borders and single nucleoli formed multiple neoplastic follicles. The final diagnosis was primary splenic lymphoma. Immunocytochemical staining results on buffy coat smears prepared from the ascites fluid showed the lymphocytes were negative for CD3 and positive for CD79a, indicating B-cell origin. Further investigation of the cell clusters using semiquantitative reverse transcriptase-PCR showed that ICAM-1, a cell-cell adhesion molecule, was overexpressed in the tumor cells, likely contributing to the clustering of neoplastic lymphocytes in the ascites fluid. Usually, round cells are not adherent; however, spontaneously detached round cells may form clusters, as in this case, and must be differentiated from epithelial tumors.