Down syndrome (DS) is associated with many neural defects, including reduced brain size and impaired neuronal proliferation, highly contributing to the mental retardation. Those typical characteristics of DS are closely associated with a specific gene group "Down syndrome critical region" (DSCR) on human chromosome 21. Here we investigated the molecular mechanisms underlying impaired neuronal proliferation in DS and, more specifically, a regulatory role for dual-specificity tyrosine-(Y) phosphorylation-regulated kinase 1A (Dyrk1A), a DSCR gene product, in embryonic neuronal cell proliferation. We found that Dyrk1A phosphorylates p53 at Ser-15 in vitro and in immortalized rat embryonic hippocampal progenitor H19-7 cells. In addition, Dyrk1A-induced p53 phosphorylation at Ser-15 led to a robust induction of p53 target genes (e.g. p21 CIP1 ) and impaired G 1 /G 0 -S phase transition, resulting in attenuated proliferation of H19-7 cells and human embryonic stem cellderived neural precursor cells. Moreover, the point mutation of p53-Ser-15 to alanine rescued the inhibitory effect of Dyrk1A on neuronal proliferation. Accordingly, brains from embryonic DYRK1A transgenic mice exhibited elevated levels of Dyrk1A, Ser-15 (mouse Ser-18)-phosphorylated p53, and p21 CIP1 as well as impaired neuronal proliferation. These findings suggest that up-regulation of Dyrk1A contributes to altered neuronal proliferation in DS through specific phosphorylation of p53 at Ser-15 and subsequent p21 CIP1 induction. Down syndrome (DS)2 is the most common genetic disorder and is caused by the presence of all or part of an extra human chromosome 21 (1). The patients have many abnormalities such as mental retardation, deficits in learning and memory, and early onset Alzheimer disease (AD) (2, 3). The brains of DS patients exhibit an arrest of neurogenesis in many CNS regions, including the hippocampus at all ages, even the fetal stage (4 -6). Cell proliferation has been shown to be impaired in human fetal DS brains and Ts65Dn mouse brains (7,8). Ts65Dn mouse possesses an extra copy of a part of chromosome 16, which corresponds to human chromosome 21, and also shows learning and memory impairments and altered neuronal proliferation in the hippocampus (8 -10). However, the molecular mechanisms underlying impaired neuronal proliferation in DS are unknown.The typical characteristics of DS are thought to be closely associated with a gene group mapped to a specific region of human chromosome 21q22 "Down syndrome critical region" (DSCR) (3). Dual-specificity tyrosine-(Y) phosphorylation-regulated kinase 1A (Dyrk1A), one of the DSCR genes, encodes a proline-directed serine/threonine kinase, which phosphorylates several transcription factors, including NFAT, CREB, and FKHR (11, 12). DYRK1A transgenic (Tg) mice, which express human DYRK1A present on a bacterial artificial chromosome, exhibit significant impairment in hippocampal-dependent memory tasks and altered synaptic plasticity, features that are similar to those seen in DS patients (13). Several ot...

Therapeutic, V.

With the gradual increase of cases using fillers, cases of patients treated by non-medical professionals or inexperienced physicians resulting in complications are also increasing. We herein report 2 patients who experienced acute complications after receiving filler injections and were successfully treated with adipose-derived stem cell (ADSCs) therapy. Case 1 was a 23-year-old female patient who received a filler (Restylane) injection in her forehead, glabella, and nose by a non-medical professional. The day after her injection, inflammation was observed with a 3×3 cm skin necrosis. Case 2 was a 30-year-old woman who received a filler injection of hyaluronic acid gel (Juvederm) on her nasal dorsum and tip at a private clinic. She developed erythema and swelling in the filler-injected area A solution containing ADSCs harvested from each patient's abdominal subcutaneous tissue was injected into the lesion at the subcutaneous and dermis levels. The wounds healed without additional treatment. With continuous follow-up, both patients experienced only fine linear scars 6 months postoperatively. By using adipose-derived stem cells, we successfully treated the acute complications of skin necrosis after the filler injection, resulting in much less scarring, and more satisfactory results were achieved not only in wound healing, but also in esthetics.