(Click to Enlarge) Human Adipocytes (HAd) (differentiated) accumulate lipid droplets visualized by Oil Red O (A). Western blot analysis of undifferentiated human pre-adipocytes (lane 1) and differentiated mature adipocytes (lane 2) lysates (B, C) . Western blot analysis of the unstimulated (lane 1) and insulin-stimulated (lane 2) differentiated human adipocytes using anti-phospho-insulin receptor antibodies (left
...Human Preadipocytes: S-HPAd: Pre-Screened
Human Preadipocytes: Pre-Screened (S-HPAd) are primary committed progenitor cells isolated from the stromal vascular fraction (SVF) of human adipose tissue. S-HPAd are true preadipocytes or SVF-derived progenitor cells,
Description
Human Preadipocytes: Pre-Screened (S-HPAd) are primary committed progenitor cells isolated from the stromal vascular fraction (SVF) of human adipose tissue. While often grouped alongside uncommitted populations in general literature, S-HPAd are true preadipocytes or SVF-derived progenitor cells, distinct from multipotent hASCs/hADSCs which retain the capacity to differentiate into osteogenic or chondrogenic lineages. Unlike human dermal fibroblasts, which are frequently used as non-adipogenic control cells, S-HPAd are already lineage-committed mesenchymal cells that retain a proliferative, fibroblast-like morphology only until induction. To eliminate the biological variability inherent to primary tissue isolates, each lot undergoes a rigorous pre-screening validation process to ensure a highly synchronized, predictable capacity to differentiate into functional, mature adipocytes. For optimal experimental results, these cells should be cultured using HPAd Growth Medium or the HPAd growth medium kit. HPAd growth supplement and preadipocyte differentiation medium are also available separately or in kits.
The pre-screening protocol ensures that S-HPAd lots maintain the fidelity of the core transcriptional hierarchy required for healthy adipocyte biology and the regulation of fat metabolism.
- Transcriptional Regulation: Lots are verified for robust adipogenic transcription factor expression, specifically PPARγ and C/EBPα. These master regulators activate the downstream genes necessary to transition from precursors to lipid-storing cells.
- Differentiation and Lipid Handling: The process is validated by tracking key metabolic nodes that govern lipid accumulation. High-quality lots demonstrate precise insulin signaling, which is critical for both the inductive phase of differentiation and subsequent metabolic homeostasis.
Once matured, S-HPAd function as insulin-responsive metabolic engines, making them invaluable for studying the mechanisms of insulin resistance, diabetes, and the systemic impacts of visceral adipose tissue.
- Lipid Dynamics: Differentiated cells are screened for their ability to manage adipocyte lipolysis and lipid catabolism, as well as their sensitivity to regulatory factors like atrial natriuretic peptide.
- Endocrine and Inflammatory Signaling: Mature S-HPAd demonstrate endocrine competence through the secretion of adiponectin. In comparative studies, researchers use these cells to model the crosstalk between adipose depots and other cell types, such as infiltrating monocytes, or to examine pathological responses like TNFα induced apoptosis.
Because they provide a verified, non-drifting baseline, S-HPAd are highly valued for pharmacological and biomedical workflows.
- Pharmacological Screening: Investigators leverage these cells to screen natural bioactives or small molecules for their ability to enhance insulin sensitivity or regulate adipogenesis.
- Microenvironmental Modeling: Beyond metabolic drug discovery, S-HPAd are deployed to investigate how the adipogenic signaling profile alters the local microenvironment, providing critical insights into how adipose tissue influences disease progression in adjacent tissues.
Human Preadipocytes (HPAd) Pre-Screened
HPAd are prescreened for Adipogenesis Signaling: Primary cultures of adipocytes are prepared by inducing differentiation of human primary preadipocytes and are prescreened for the expression of the following major adipocyte markers:
- PPARγ (Peroxisome proliferator-activated receptor gamma), an adipocyte-specific nuclear hormone receptor
- C/EBPα (CCAAT/enhancer binding protein alpha), a transcription factor involved in creating and maintaining the adipocyte phenotype
- IR (Insulin receptor), which plays a critical role in induction of adipocyte differentiation, as well as functional regulation
- ACCα (Acetyl-CoA carboxylase alpha), a key enzyme for de novo fatty acid synthesis and lipogenic capability of adipocytes
- GSK-3β (Glycogen synthase kinase-3-beta), a ubiquitous kinase implicated in regulation of adipocyte gene expression, signaling, adipogenesis, insulin action and glycogen synthesis
- Adiponectin, a bioactive adipokine specifically secreted by differentiated adipocyte and involved in metabolic regulation
Details
(Detail for Figure) Human Preadipocytes: HPAd: Pre-Screened. High level expression of both PPARg and C/EBPa proteins was detected in our prescreened human adipocytes but not in the undifferentiated preadipocytes (Fig. B). Additionally, IR expression is dramatically increased in the prescreened human adipocytes as compared to that in undifferentiated preadipocytes. There was also a slight increase in Akt expression in differentiated adipocytes. Our results further demonstrate higher expression levels for both metabolic enzymes, ACCa and GSK-3b, in the mature adipocytes compared to the undifferentiated preadipocytes. Adiponectin was also detected only in the mature adipocytes, but not in the undifferentiated preadipocytes (Fig. C). Insulin is not only critical to adipocyte differentiation, but also serves as a key metabolic regulator. Thus, insulin response is a characteristic assay for adipocyte function. We confirmed that the pre-screened adipocytes respond strongly to insulin stimulation (Fig. D). Strong phosphorilation of Tyr 1165/6 of insulin receptor was detected in the insulin-stimulated (lane 2), but not in untreated adipocytes (lane 1). Total insulin receptor levels did not change before and after insulin stimulation (right blot).
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