Liposuction aspirates (primarily saline solution, blood, and adipose tissue fragments) separate into fatty and fluid portions. Cells isolated from the fatty portion are termed processed lipoaspirate (PLA) cells and contain adipose-derived adherent stromal cells (ASCs). Here we define cells isolated from the fluid portion of liposuction aspirates as liposuction aspirate fluid (LAF) cells. Stromal vascular fractions (SVF) were isolated separately from both portions and characterized under cultured and non-cultured conditions. A comparable number of LAF and PLA cells were freshly isolated, but fewer LAF cells were adherent. CD34+ CD45- cells from fresh LAF isolates were expanded by adherent culture, suggesting that LAF cells contain ASCs. Although freshly isolated PLA and LAF cells have distinct cell surface marker profiles, adherent PLA and LAF cells have quite similar characteristics with regard to growth kinetics, morphology, capacity for differentiation, and surface marker profiles. After plating, both PLA and LAF cells showed significant increased expression of CD29, CD44, CD49d, CD73, CD90, CD105, and CD151 and decreased expression of CD31 and CD45. Multicolor FACS analysis revealed that SVF are composed of heterogeneous cell populations including blood-derived cells (CD45+), ASCs (CD31- CD34+ CD45- CD90+ CD105- CD146-), endothelial (progenitor) cells (CD31+ CD34+ CD45- CD90+ CD105low CD146+), pericytes (CD31- CD34- CD45- CD90+ CD105- CD146+), and other cells. After plating, ASCs showed a dramatic increase in CD105 expression. Although some adherent ASCs lost CD34 expression with increasing culture time, our culture method maintained CD34 expression in ASCs for at least 10-20 weeks. These results suggest that liposuction-derived cells may be useful and valuable for cell-based therapies.

Injective transfer of autologous aspirated fat is a popular option for soft tissue augmentation, but several issues require attention, including unpredictability and a low survival rate due to partial necrosis. In this study, histologic features and yield of adipose-derived stromal (stem) cells (ASCs) were compared between human aspirated fat and excised whole fat. Aspirated fat contained fewer large vascular structures, and ASC yield was lower in aspirated fat. Aspirated fat was transplanted subcutaneously into severe combined immunodeficiency mice with (cell-assisted lipotransfer; CAL) or without (non-CAL) vascular stromal fractions containing ASCs isolated from adipose tissue. The CAL fat survived better (35% larger on average) than non-CAL fat, and microvasculature was detected more prominently in CAL fat, especially in the outer layers. DiI-labeled vascular stromal fraction cells were found between adipocytes and in the connective tissue in CAL fat, and some of these cells were immunopositive for von Willebrand factor, suggesting differentiation into vascular endothelial cells. Another experiment that used vascular stromal fractions taken from green fluorescent protein rats also suggested that ASCs differentiated into vascular endothelial cells and contributed to neoangiogenesis in the acute phase of transplantation. These findings may partly explain why transplanted aspirated fat does not survive well and suggest clinical potential of the CAL method for soft tissue augmentation.

H. Multiple renal cysts, urinary concentration defects, and pulmonary emphysematous changes in mice lacking TAZ.

Ghrelin, a gastric-derived acylated peptide, regulates energy homeostasis by transmitting information about peripheral nutritional status to the brain, and is essential for protecting organisms against famine. Ghrelin operates brain circuits to regulate homeostatic and hedonic feeding. Recent research advances have shed new light on ghrelin's multifaceted roles in cellular homeostasis, which could maintain the internal environment and overcome metaflammation in metabolic organs. Here, we highlight our current understanding of the regulatory mechanisms of the ghrelin system in energy metabolism and cellular homeostasis and its clinical trials. Future studies of ghrelin will further elucidate how the stomach regulates systemic homeostasis.

SUMMARY: Cyclin-Dependent Kinase 9 (CDK9) promotes transcriptional elongation through RNAPII pause release. We now report that CDK9 is also essential for maintaining gene silencing at heterochromatic loci. Through a live cell drug screen with genetic confirmation, we discovered that CDK9 inhibition reactivates epigenetically silenced genes in cancer, leading to restored tumor suppressor gene expression, cell differentiation, and activation of endogenous retrovirus genes. CDK9 inhibition dephosphorylates the SWI/SNF protein BRG1, which contributes to gene reactivation. By optimization through gene expression, we developed a highly selective CDK9 inhibitor (MC180295, IC50=5nM) that has broad anti-cancer activity in-vitro and is effective in in-vivo cancer models. Additionally, CDK9 inhibition sensitizes to the immune checkpoint inhibitor α-PD-1 in vivo, making it an excellent target for epigenetic therapy of cancer.