Misalignment of physiological circadian rhythms promotes obesity which is characterized by white adipose tissue (WAT) expansion. Differentiation of Adipose stem/progenitor cells (ASCs) contributes to WAT increase but the importance of the cellular clock in this process is incompletely understood. In the present study, we reveal the role of the circadian transcription factor Aryl hydrocarbon receptor nuclear translocator-like 2 (ARNTL2) in human ASCs, isolated from subcutaneous (s)WAT samples of patients undergoing routine elective plastic abdominal surgery.
View Article and Find Full Text PDFWe established a functional adipose organoid model system for human adipose stem/progenitor cells (ASCs) isolated from white adipose tissue (WAT). ASCs were forced to self-aggregate by a hanging-drop technique. Afterwards, spheroids were transferred into agar-coated cell culture dishes to avoid plastic-adherence and dis-aggregation.
View Article and Find Full Text PDFWe explore the status of quiescence, stemness and adipogenic differentiation capacity in adipose stem/progenitor cells (ASCs) ex vivo, immediately after isolation from human subcutaneous white adipose tissue, by sorting the stromal vascular fraction into cell-surface DLK1/CD34, DLK1/CD34 and DLK1/CD34 cells. We demonstrate that DLK1/CD34 cells, the only population exhibiting proliferative and adipogenic capacity, express ex vivo the bonafide quiescence markers p21, p27 and p57 but neither proliferation markers nor the senescence marker p16. The pluripotency markers NANOG, SOX2 and OCT4 are barely detectable in ex vivo ASCs while the somatic stemness factors, c-MYC and KLF4 and the early adipogenic factor C/EBPβ are highly expressed.
View Article and Find Full Text PDFThe CRISPR/Cas9 system is a powerful tool to generate a specific loss-of-function phenotype by gene knockout (KO). However, this approach is challenging in primary human cells. In this technical report, we present a reliable protocol to achieve a functional KO in the genome of human adipose stem/progenitor cells (ASCs).
View Article and Find Full Text PDFThe role of Ras-Mitogen-activated protein kinase (MAPK) signaling in cellular aging is not precisely understood. Recently, we identified Sprouty1 (SPRY1) as a weight-loss target gene in human adipose stem/progenitor cells (ASCs) and showed that Sprouty1 is important for proper regulation of adipogenesis. In the present study, we show that loss-of-function of Sprouty1 by CRISPR/Cas9-mediated genome editing in human ASCs leads to hyper-activation of MAPK signaling and a senescence phenotype.
View Article and Find Full Text PDFThe differentiation of adipose stem/progenitor cells (ASCs) into adipocytes contributes to adipose tissue expansion in obesity. This process is regulated by numerous signalling pathways including MAPK signalling. In the present study, we show that weight loss (WL) interventions induce upregulation of Sprouty1 (SPRY1), a negative regulator of MAPK signalling, in human ASCs and elucidate the role of the Sprouty1/MAPK interaction for adipogenic differentiation.
View Article and Find Full Text PDFAdipose stromal/progenitor cells (ASCs) can differentiate into adipocytes in the course of adipogenesis. This process is governed by systemic factors and signals of the adipose stem cell niche. ASCs isolated from fat tissues and amplified in vitro provide an essential and reliable model system to study adipogenesis.
View Article and Find Full Text PDFBackground: The proliferation and adipogenic differentiation of adipose stromal cells (ASCs) are complex processes comprising major phenotypical alterations driven by up- and downregulation of hundreds of genes. Quantitative RT-PCR can be employed to measure relative changes in the expression of a gene of interest. This approach requires constitutively expressed reference genes for normalization to counteract inter-sample variations due to differences in RNA quality and quantity.
View Article and Find Full Text PDFPurpose: The primary aim of the study was to analyze whether there is and - if so - how far a correlation between the clinical findings after carpal tunnel release (CTR) for carpal tunnel syndrome (CTS) and the Wrist-to-Forearm-Ratio (WFR) of the median nerve in ultrasound to answer is question whether the WFR can be used in controlling the operative result.
Patients And Methods: In a prospective study the clinical, electrophysiological, and sonographic data of 40 patients with CTR for CTS were collected preoperative and 3 and 9 months postoperative. The data of 21 patients with 23 operated hands completing the study were analyzed.
To precisely characterize CD146 in adipose stromal/progenitor cells (ASCs) we sorted the stromal vascular faction (SVF) of human abdominal subcutaneous white adipose tissue (sWAT) according to cell surface (cs) expression of CD146, DLK1 and CD34. This test identified three main SVF cell populations: ~50% cs-DLK1/cs-CD34/cs-CD146 ASCs, ~7.5% cs-DLK1/cs-CD34/cs-CD146 and ~7.
View Article and Find Full Text PDFInhibition of Akt-mTOR signaling protects from obesity and extends life span in animals. In the present study, we analyse the impact of the small GTPase, GTP-binding RAS-like 3 (DIRAS3), a recently identified weight-loss target gene, on cellular senescence in adipose stromal/progenitor cells (ASCs) derived from human subcutaneous white adipose tissue (sWAT). We demonstrate that DIRAS3 knock-down (KD) in ASCs induces activation of Akt-mTOR signaling and proliferation arrest.
View Article and Find Full Text PDFLong-term weight-loss (WL) interventions reduce insulin serum levels, protect from obesity, and postpone age-associated diseases. The impact of long-term WL on adipose-derived stromal/progenitor cells (ASCs) is unknown. We identified DIRAS3 and IGF-1 as long-term WL target genes up-regulated in ASCs in subcutaneous white adipose tissue of formerly obese donors (WLDs).
View Article and Find Full Text PDFBackground: Fibrotic diseases encompass numerous systemic and organ-specific disorders characterized by the development and persistence of myofibroblasts. TGFβ1 is considered the key inducer of fibrosis and drives myofibroblast differentiation in cells of diverse histological origin by a pro-oxidant shift in redox homeostasis associated with decreased nitric oxide (NO)/cGMP signaling. Thus, enhancement of NO/cGMP represents a potential therapeutic strategy to target myofibroblast activation and therefore fibrosis.
View Article and Find Full Text PDFSorting of native (unpermeabilized) SVF-cells from human subcutaneous (s)WAT for cell surface staining (cs) of DLK1 and CD34 identified three main populations: ~10% stained cs-DLK1+/cs-CD34-, ~20% cs-DLK1+/cs-CD34+dim and ~45% cs-DLK1-/cs-CD34+. FACS analysis after permeabilization showed that all these cells stained positive for intracellular DLK1, while CD34 was undetectable in cs-DLK1+/cs-CD34- cells. Permeabilized cs-DLK1-/cs-CD34+ cells were positive for the pericyte marker α-SMA and the mesenchymal markers CD90 and CD105, albeit CD105 staining was dim (cs-DLK1-/cs-CD34+/CD90+/CD105+dim/α-SMA+/CD45-/CD31-).
View Article and Find Full Text PDFFollowing my prior study of long-term results after laparoscopic gastric banding concerning operative outcome and complications involving the gastric band itself, I now focus on long-term quality-of-life improvement in the same study group after body-contouring surgery. As determined from our electronic patient data system, 72 patients from the former study group subsequently sought body-contouring surgery at our hospital after successful weight loss. Patients were enrolled in a telephone interview and asked about their expectations and body image before and after postbariatric aesthetic surgery and how it altered their well-being in addition to the weight loss achieved with the gastric band.
View Article and Find Full Text PDFA key effect of prolonged reducing diets and bariatric surgeries in formerly obese people is long-term caloric restriction (CR). The analysis of the impact of these interventions on specific tissues will contribute to a better understanding of their mechanisms of action. The physiological functions of subcutaneous white adipose tissues are mainly fulfilled by adipocytes arising out of adipose-derived stromal/progenitor cells (ASCs), which are crucial for adipose tissue homeostasis.
View Article and Find Full Text PDFWe demonstrate that adipose-derived stromal/progenitor cells isolated from abdominal subcutaneous fat pads of adult donors successively enter replicative senescence after long-term cultivation. This is characterized by enlarged cell size, flattened morphology, and upregulated senescence-associated β-galactosidase activity. Moreover, the senescence- associated cyclin-dependent kinase inhibitors p16(Ink4A) and p21(Cip1) were induced correlating with activation of the G1/S cell cycle inhibitor retinoblastoma protein and terminal proliferation arrest.
View Article and Find Full Text PDFWe investigated the role of the major isoforms of CCAAT enhancer binding protein β (C/EBPβ), C/EBPβ-LAP and C/EBPβ-LIP, in adipogenesis of human white adipose-derived stromal/progenitor cells (ASC). C/EBPβ gene expression was transiently induced early in adipogenesis. At later stages, in immature adipocytes, the C/EBPβ mRNA and protein levels declined.
View Article and Find Full Text PDFThe main physiological function of adipose-derived stromal/progenitor cells (ASC) is to differentiate into adipocytes. ASC are most likely localized at perivascular sites in adipose tissues and retain the capacity to differentiate into multiple cell types. Although cell surface markers for ASC have been described, there is no complete consensus on the antigen expression pattern that will precisely define these cells.
View Article and Find Full Text PDFObjective: The purpose of this report was to present abnormal posttraumatic cold intolerance in patients that previously underwent repair of arterial injuries after civilian upper limb trauma in our institution.
Methods: All patients who underwent repair of arterial lesions after upper limb trauma since 1990 were reviewed, and clinical follow-up studies were performed. Patients were asked to complete the cold intolerance symptom severity (CISS) questionnaire to evaluate presence and severity of self-reported cold sensitivity, and the disabilities of arm, shoulder, and hand (DASH) questionnaire to analyze functional disability.
J Gerontol A Biol Sci Med Sci
November 2011
Life-span extension in laboratory rodents induced by long-term caloric restriction correlates with decreased serum insulin-like growth factor-I (IGF-I) levels. Reduced activity of the growth hormone/IGF-I signaling system slows aging and increases longevity in mutant mouse models. In the present study, we show that long-term caloric restriction achieved by two different interventions for 4 years, either laparoscopic-adjustable gastric banding or reducing diet, leads to reduced IGF-I serum levels in formerly obese women relative to normal-weight women eating ad libitum.
View Article and Find Full Text PDFTo better understand the contribution of the fat mass to the effects of long-term caloric restriction in humans, we compared adipokine profile and insulin sensitivity in long-term calorically restricted formerly obese women (CRW) subjected to different interventions, bariatric surgery, or reducing diet, with age- and BMI-matched obese (OW) and normal-weight women (NW) eating ad libitum. Our key findings are that despite a considerably stronger weight loss induced by bariatric surgery, both long-term caloric restriction interventions improved insulin sensitivity to the same degree and led to significantly lower retinol-binding protein-4 and interleukin-6 serum levels than in OW, suggesting that lowering of these two adipokines contributes to the improved insulin sensitivity. Moreover, serum leptin was considerably lower in CRW than in OW as well as in NW, suggesting that CRW develop hypoleptinemia.
View Article and Find Full Text PDFWe have previously established a chamber model of tissue engineering that promotes de novo angiogenesis and vascularization of engrafted cells and tissues when combined with an extracellular matrix. Here we demonstrate that the mouse chamber (MC) model can sustain ectopic grafts of murine fetal thymus lobes and, to a limited degree, human pediatric thymus tissue, resulting in de novo T-cell production. Silicone chambers containing Matrigel((R)) and thymus tissues were placed around exposed epigastric vessels and the ends sealed with bone wax, before implantation into the inguinal fat pad of athymic Balb/c(nu/nu) (nude) mice.
View Article and Find Full Text PDFMedullary thymic epithelial cells (mTEC) play an important and unique role in central tolerance, expressing tissue-restricted Ags (TRA) which delete thymocytes autoreactive to peripheral organs. Since deficiencies in this cell type or activity can lead to devastating autoimmune diseases, it is important to understand the factors which regulate mTEC differentiation and function. Lymphotoxin (LT) ligands and the LTbetaR have been recently shown to be important regulators of mTEC biology; however, the precise role of this pathway in the thymus is not clear.
View Article and Find Full Text PDFBackground: The authors investigated the predictive value of various parameters such as age, preoperative weight, eating behavior, psychiatric disorders, adverse childhood experiences and self-efficacy with regard to weight loss after gastric restrictive surgery.
Methods: After a minimum follow-up of 30 months (median follow-up 50 months; range 30-84 months), a questionnaire concerning extent of, satisfaction with, and consequences of weight loss was mailed to 220 morbidly obese female patients following laparoscopic Swedish adjustable gastric banding (SAGB).
Results: Questionnaires were completed and returned by 140 patients (63%).