Effects of epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) on human adipocyte development and function

The optimized priming effect of FGF-1 and FGF-2 enhances preadipocyte lineage commitment in human adipose-derived mesenchymal stem cells

The cell-assisted lipotransfer technique, integrating adipose-derived mesenchymal stem cells (ADMSCs), has transformed lipofilling, enhancing fat graft viability. However, the multipotent nature of ADMSCs poses challenges. To improve safety and graft vitality and to reduce unwanted lineage differentiation, this study refines the methodology by priming ADMSCs into preadipocytes-unipotent, self-renewing cells. We explored the impact of fibroblast growth factor-1 (FGF-1), fibroblast growth factor-2 (FGF-2), and epidermal growth factor (EGF), either alone or in combination, on primary human ADMSCs during the proliferative phase. FGF-2 emerged as a robust stimulator of cell proliferation, preserving stemness markers, especially when combined with EGF. Conversely, FGF-1, while not significantly affecting cell growth, influenced cell morphology, transitioning cells to a rounded shape with reduced CD34 expression. Furthermore, co-priming with FGF-1 and FGF-2 enhanced adipogenic potential, limiting osteogenic and chondrogenic tendencies, and possibly promoting preadipocyte commitment. These preadipocytes exhibited unique features: rounded morphology, reduced CD34, decreased preadipocyte factor 1 (Pref-1), and elevated C/EBPα and PPARγ, alongside sustained stemness markers (CD73, CD90, CD105). Mechanistically, FGF-1 and FGF-2 activated key adipogenic transcription factors-C/EBPα and PPARγ-while inhibiting GATA3 and Notch3, which are adipogenesis inhibitors. These findings hold the potential to advance innovative strategies for ADMSC-mediated lipofilling procedures.

Perinatal triphenyl phosphate exposure induces metabolic dysfunctions through the EGFR/ERK/AKT signaling pathway: Mechanistic in vitro and in vivo studies

Triphenyl phosphate (TPhP), a widely used organophosphate-flame retardant, is ubiquitously found in household environments and may adversely affect human health. Evidence indicates that TPhP exposure causes metabolic dysfunctions in vivo; however, the underlying mechanism of such adverse effects has not been comprehensively investigated. Herein, we utilized two in vitro models including mouse and human preadipocytes to delineate adipogenic mechanisms of TPhP. The results revealed that both mouse and human preadipocytes exposed to TPhP concentration-dependently accumulated more fat through a significant upregulation of epidermal growth factor receptor (EGFR). We demonstrated that TPhP significantly promoted adipogenesis through the activation of EGFR/ERK/AKT signaling pathway as evident by a drastic reduction in adipogenesis of preadipocytes cotreated with inhibitors of EGFR and its major effectors. Furthermore, we confirmed the mechanism of TPhP-induced metabolic dysfunctions in vivo. We observed that male mice perinatally exposed to TPhP had a significant increase in adiposity, hepatic triglycerides, insulin resistance, plasma insulin levels, hypotension, and phosphorylated EGFR in gonadal fat. Interestingly, an administration of a potent and selective EGFR inhibitor significantly ameliorated the adverse metabolic effects caused by TPhP. Our findings uncovered a potential mechanism of TPhP-induced metabolic dysfunctions and provided implications on toxic metabolic effects posed by environmental chemicals.

Recent Advances in Stem Cell Differentiation Control Using Drug Delivery Systems Based on Porous Functional Materials

The unique characteristics of stem cells, which include self-renewal and differentiation into specific cell types, have paved the way for the development of various biomedical applications such as stem cell therapy, disease modelling, and drug screening. The establishment of effective stem cell differentiation techniques is essential for the effective application of stem cells for various purposes. Ongoing research has sought to induce stem cell differentiation using diverse differentiation factors, including chemicals, proteins, and integrin expression. These differentiation factors play a pivotal role in a variety of applications. However, it is equally essential to acknowledge the potential hazards of uncontrolled differentiation. For example, uncontrolled differentiation can give rise to undesirable consequences, including cancerous mutations and stem cell death. Therefore, the development of innovative methods to control stem cell differentiation is crucial. In this review, we discuss recent research cases that have effectively utilised porous functional material-based drug delivery systems to regulate stem cell differentiation. Due to their unique substrate properties, drug delivery systems based on porous functional materials effectively induce stem cell differentiation through the steady release of differentiation factors. These ground-breaking techniques hold considerable promise for guiding and controlling the fate of stem cells for a wide range of biomedical applications, including stem cell therapy, disease modelling, and drug screening.

Generation of functional fat organoid from rat superficial fascia

The organoid is a 3D cell architecture formed by self-organized tissues or cells in vitro with similar cell types, histological structures, and biological functions of the native organ. Depending on the unique organ structures and cell types, producing organoids requires individualized design and is still challenging. Organoids of some tissues, including adipose tissue, remain to generate to be more faithful to their original organ in structure and function. We previously established a new model of the origin of adipose cells originating from non-adipose fascia tissue. Here, we investigated superficial fascia fragments in 3D hydrogel and found they were able to transform into relatively large adipocyte aggregates containing mature unilocular adipocytes, which were virtually "fat organoids". Such fascia-originated fat organoids had a typical structure of adipose tissues and possessed the principal function of adipose cells in the synthesis, storage, hydrolysis of triglycerides and adipokines secretion. Producing fat organoids from superficial fascia can provide a new approach for adipocyte research and strongly evidences that both adipose tissues and cells originate from fascia. Our findings give insights into metabolic regulation by the crosstalk between different organs and tissues and provide new knowledge for investigating novel treatments for obesity, diabetes and other metabolic diseases.Abbreviations: 3D: three dimensional; ASC: adipose-derived stromal cells; C/EBP: CCAAT-enhancer-binding protein; EdU: 5-ethynyl-2-deoxyuridine; FABP4: fatty acid-binding protein 4; FAS: fatty acid synthase; FSCs: fascia-derived stromal cells; Plin1: perilipin-1; Plin2: perilipin-2; PPARγ: peroxisome proliferator-activated receptor γ; WAT: white adipose tissue.

Adipokines: Deciphering the cardiovascular signature of adipose tissue

Obesity and hypertension are intimately linked due to the various ways that the important cell types such as vascular smooth muscle cells (VSMC), endothelial cells (EC), immune cells, and adipocytes, communicate with one another to contribute to these two pathologies. Adipose tissue is a very dynamic organ comprised primarily of adipocytes, which are well known for their role in energy storage. More recently adipose tissue has been recognized as the largest endocrine organ because of its ability to produce a vast number of signaling molecules called adipokines. These signaling molecules stimulate specific types of cells or tissues with many adipokines acting as indicators of adipocyte healthy function, such as adiponectin, omentin, and FGF21, which show anti-inflammatory or cardioprotective effects, acting as regulators of healthy physiological function. Others, like visfatin, chemerin, resistin, and leptin are often altered during pathophysiological circumstances like obesity and lipodystrophy, demonstrating negative cardiovascular outcomes when produced in excess. This review aims to explore the role of adipocytes and their derived products as well as the impacts of these adipokines on blood pressure regulation and cardiovascular homeostasis.

Personalized Nutrition Approach in Pregnancy and Early Life to Tackle Childhood and Adult Non-Communicable Diseases

The development of childhood and adult non-communicable diseases (NCD) is associated with environmental factors, starting from intrauterine life. A new theory finds the roots of epigenetic programming in parental gametogenesis, continuing during embryo development, fetal life, and finally in post-natal life. Maternal health status and poor nutrition are widely recognized as implications in the onset of childhood and adult diseases. Early nutrition, particularly breastfeeding, also plays a primary role in affecting the health status of an individual later in life. A poor maternal diet during pregnancy and lack of breastfeeding can cause a nutrient deficiency that affects the gut microbiota, and acts as a cofactor for many pathways, impacting the epigenetic controls and transcription of genes involved in the metabolism, angiogenesis, and other pathways, leading to NCDs in adult life. Both maternal and fetal genetic backgrounds also affect nutrient adsorption and functioning at the cellular level. This review discusses the most recent evidence on maternal nutrition and breastfeeding in the development of NCD, the potentiality of the omics technologies in uncovering the molecular mechanisms underlying it, with the future prospective of applying a personalized nutrition approach to prevent and treat NCD from the beginning of fetal life.

Optimization of Co-Culture Conditions for a Human Vascularized Adipose Tissue Model

In vitro adipose tissue models can be used to provide insight into fundamental aspects of adipose physiology. These systems may serve as replacements for animal models, which are often poor predictors of obesity and metabolic diseases in humans. Adipose tissue consists of a rich vasculature that is essential to its function. However, the study of endothelial cell–adipocyte interactions has been challenging due to differences in culture conditions required for the survival and function of each cell type. To address this issue, we performed an extensive evaluation of the cell culture media composition to identify the conditions optimal for the co-culture of endothelial cells and adipocytes. The effects of individual media factors on cell survival, proliferation, and differentiation were systematically explored. Several media factors were determined to disrupt the co-culture system. Optimized culture conditions were identified and used to generate a vascularized human adipose microtissue. An interconnected vascular network was established within an adipose micro-tissue, and the networks were anastomosed with perfused channels to form a functional network. In conclusion, media conditions were identified that enabled endothelial cell–adipocyte co-culture and were used to support the formation of a vascularized adipose tissue within a microfluidic device.

Identification and characterization of adipose surface epitopes

Adipose tissue is a central regulator of metabolism and an important pharmacological target to treat the metabolic consequences of obesity, such as insulin resistance and dyslipidemia. Among the various cellular compartments, the adipocyte cell surface is especially appealing as a drug target as it contains various proteins that when activated or inhibited promote adipocyte health, change its endocrine function and eventually maintain or restore whole-body insulin sensitivity. In addition, cell surface proteins are readily accessible by various drug classes. However, targeting individual cell surface proteins in adipocytes has been difficult due to important functions of these proteins outside adipose tissue, raising various safety concerns. Thus, one of the biggest challenges is the lack of adipose selective surface proteins and/or targeting reagents. Here, we discuss several receptor families with an important function in adipogenesis and mature adipocytes to highlight the complexity at the cell surface and illustrate the problems with identifying adipose selective proteins. We then discuss that, while no unique adipocyte surface protein might exist, how splicing, posttranslational modifications as well as protein/protein interactions can create enormous diversity at the cell surface that vastly expands the space of potentially unique epitopes and how these selective epitopes can be identified and targeted.

Breastfeeding and childhood obesity: A 12-country study

This study aimed to examine the association between breastfeeding and childhood obesity. A multinational cross‐sectional study of 4,740 children aged 9–11 years was conducted from 12 countries. Infant breastfeeding was recalled by parents or legal guardians. Height, weight, waist circumference, and body fat were obtained using standardized methods. The overall prevalence of obesity, central obesity, and high body fat were 12.3%, 9.9%, and 8.1%, respectively. After adjustment for maternal age at delivery, body mass index (BMI), highest maternal education, history of gestational diabetes, gestational age, and child's age, sex, birth weight, unhealthy diet pattern scores, moderate‐to‐vigorous physical activity, sleeping, and sedentary time, exclusive breastfeeding was associated with lower odds of obesity (odds ratio [OR] 0.76, 95% confidence interval, CI [0.57, 1.00]) and high body fat (OR 0.60, 95% CI [0.43, 0.84]) compared with exclusive formula feeding. The multivariable‐adjusted ORs based on different breastfeeding durations (none, 1–6, 6–12, and > 12 months) were 1.00, 0.74, 0.70, and 0.60 for obesity (P_trend = .020) and 1.00, 0.64, 047, and 0.64 for high body fat (P_trend = .012), respectively. These associations were no longer significant after adjustment for maternal BMI. Breastfeeding may be a protective factor for obesity and high body fat in 9‐ to 11‐year‐old children from 12 countries.

Effects of Breastfeeding and Formula Feeding on the Expression Level of FTO, CPT1A and PPAR-α Genes in Healthy Infants

PURPOSE

The study aimed to investigate the effect of breastfeeding, formula feeding and mix feeding (breastfed plus formula-fed) on the expression level of obesity-predisposing genes including fat mass and obesity-associated (FTO), carnitine palmitoyltransferase 1A (CPT1A), and peroxisome proliferator-activated receptor-α (PPAR-α) in 5- to 6-month-old infants.

PATIENTS AND METHODS

A total of 150 infants participated in this case-control study. All subjects were healthy infants aged 5-6 months that divided into 3 groups: breastfed, formula-fed, and mix-fed. The expression level of FTO, CPT1A, and PPAR-α genes in peripheral blood mononuclear cells (PBMC) was evaluated in each group using reverse transcription-polymerase chain reaction (RT-PCR) method.

RESULTS

Our findings showed that the current weight, height, and head circumference of infants in the formula feeding and mix feeding groups were significantly higher than those in the exclusive breastfeeding group. The expression level of FTO and CPT1A genes in formula-fed and mix-fed infants was significantly higher (p<0.001) than that in breastfed infants, while the expression level of PPAR-α gene was significantly lower (p<0.05).

CONCLUSION

Breastfeeding showed modulatory effects on the expression level of obesity-predisposing genes and can protect against obesity and subsequent non-communicable diseases. However, more investigations are required to explain the epigenetic effects of breast milk.

LncRNA TUG1 regulates FGF1 to enhance endothelial differentiation of adipose-derived stem cells by sponging miR-143

Adipose-derived stem cells (ADSCs) have emerged as a cell source for regeneration medicine. ADSCs possess the capacity to differentiate into endothelial cells and serve an essential role in vascular development and function. LncRNA taurine upregulated gene 1 (TUG1) has recently been linked with angiogenesis in hepatoblastoma. However, the roles of TUG1 in endothelial differentiation of ADSCs remain unidentified. Human adipose-derived stem cells (hADSCs) were obtained and characterized by flow cytometry, Oil red O and Alizarin Red staining. HADSCs were maintained in the endothelial differentiation medium and the expressions of TUG1, miR-143, and FGF1 were examined by qRT-PCR. To assess endothelial differentiation, the expressions of CD31, von Willebrand factor (vWF), VE-cadherin were examined by Western blot analysis, qRT-PCR, and immunofluorescence. Tube formation in Matrigel was examined. The interactions between TUG1 and miR-143, miR-143 and FGF1 were validated by luciferase assays. During the endothelial differentiation process, TUG1 and FGF1 were upregulated, whereas miR-143 was downregulated. TUG1 overexpression downregulated miR-143, upregulated FGF1, CD31, vWF, and VE-cadherin, and enhanced capillary tube formation. Luciferase assays showed that TUG1 interacted with miR-143, and FGF1 was a direct target of miR-143. Furthermore, the enhancement of endothelial differentiation induced by TUG1 overexpression was abolished by miR-143 overexpression. Our findings implicated that lncRNA TUG1 promoted endothelial differentiation of ADSCs by regulating the miR-143/FGF1 axis.

An updated review of adipose derived-mesenchymal stem cells and their applications in musculoskeletal disorders

INTRODUCTION

Adipose-derived mesenchymal stem cells (ASCs) represent a new therapeutic strategy in biomedicine with many potential applications, especially in musculoskeletal disorders. Preclinical and clinical studies based on the administration of ASCs support their efficacy in bone regeneration, joint repair, tendon injury and skeletal muscle alterations. Many of these novel treatments may improve patients' quality of life and prognosis. However, several concerns about the use of stem cells remain unsolved, particularly regarding their safety and side effects. The present work aims to review the nature, clinical trials and patents involving the use of ASCs in musculoskeletal disorders.

AREAS COVERED

In this article, we describe ASCs' isolation, culture and differentiation in vivo and in vitro, advances on ASCs' applications in bone, cartilage, muscle and tendon repair, and patents involving the use of ASCs.

EXPERT OPINION

The use of ASCs in musculoskeletal disorders presents significant therapeutic advantages, including limited autoimmune response, potential cell expansion ex vivo, high plasticity to differentiate into several mesodermal cell lineages, and additional effects of therapeutic interest such as secretion of neurotrophic factors and anti-inflammatory properties. For these reasons, ASCs are promising therapeutic agents for clinical applications in musculoskeletal disorders.

Betaine promotes lipid accumulation in adipogenic-differentiated skeletal muscle cells through ERK/PPARγ signalling pathway

Betaine, a neutral zwitterionic compound, could regulate intramuscular fat (IMF) deposition and meat quality. However, the efficacy is controversial. Moreover, the regulatory mechanism of betaine on lipid metabolism in skeletal muscle cells remains unclear. Therefore, in this study, we examined the effects and regulatory mechanism of betaine on lipid accumulation in adipogenic-differentiated C2C12 cells. We found that adipogenic-induced C2C12 cells treated with 10 mM betaine for 24 and 48 h had more lipid accumulation than the control group. Real-time PCR and Western blot results revealed that betaine treatment did not alter the expression of lipolysis and lipid oxidation-related genes, but dramatically increased the expression of peroxisome proliferator-activated receptor γ (PPARγ) and its target genes such as fatty acid binding protein 4 (aP2), fatty acid synthase (FAS) and lipoprteinlipase (LPL). Furthermore, betaine combined with PPARγ inhibitor GW9662 treatment showed that betaine elevated C2C12 lipid accumulation through upregulation of PPARγ. Mechanistically, we found that betaine promoted PPARγ expression and lipid accumulation through inhibition of extracellular regulated protein kinases1/2 (ERK1/2) signalling pathway. These results demonstrate that betaine acts through ERK1/2-PPARγ signalling pathway to regulate lipid metabolism in adipogenic-differentiated skeletal muscle cells, which could provide some useful information for controlling muscle lipid accumulation by manipulating ERK1/2 and PPARγ signalling pathway.

Effect of human milk formula with bovine colostrum supplementation on bone mineral density in infant cynomolgus macaques

Insulin-like growth factor 1 (IGF1) is a regulator of human growth during infancy and childhood, known to promote bone and muscle growth as well as lipid accumulation. This study aimed to investigate the effects of formula milk with or without IGF1 supplementation (in the form of pure IGF1 or bovine colostrum) on growth and body composition in infant cynomolgus macaques during the first 6 months of life. Three groups of infants were nursery-reared and received formula milk with or without IGF1 or bovine colostrum supplementation for 4 months, and a fourth group consisting of breast-fed infants was included for comparison (n=6 for each group). Ranked-based analysis of covariance was used to detect differences between adjusted means for sex. No differences in weight, height, fat mass, and fat-free mass could be detected between groups. However, bone mineral density (BMD) was significantly different between groups at the end of formula feeding. Infants that received bovine colostrum supplementation displayed higher mean BMD than infants of all other groups, with no differences between the latter three groups. In conclusion, our results suggest that supplementation with bovine colostrum can enhance BMD in formula-fed infants, an effect that apparently does not depend on IGF1. Bovine colostrum supplementation could be beneficial for long-term bone health in infants with suboptimal bone growth.

Differentiation and Metabolic Interrogation of Human Adipocytes

Adipocytes differentiated from preadipocytes provide a valuable model for the study of human adipocyte metabolism. We describe methods for isolation of human stromal vascular cells, expansion of preadipocytes, differentiation into mature adipocytes, and in vitro metabolic interrogation of adipocytes.

Suppression of Resting Metabolism by the Angiotensin AT2 Receptor

Activation of the brain renin-angiotensin system (RAS) stimulates energy expenditure through increasing of the resting metabolic rate (RMR), and this effect requires simultaneous suppression of the circulating and/or adipose RAS. To identify the mechanism by which the peripheral RAS opposes RMR control by the brain RAS, we examined mice with transgenic activation of the brain RAS (sRA mice). sRA mice exhibit increased RMR through increased energy flux in the inguinal adipose tissue, and this effect is attenuated by angiotensin II type 2 receptor (AT2) activation. AT2 activation in inguinal adipocytes opposes norepinephrine-induced uncoupling protein-1 (UCP1) production and aspects of cellular respiration, but not lipolysis. AT2 activation also opposes inguinal adipocyte function and differentiation responses to epidermal growth factor (EGF). These results highlight a major, multifaceted role for AT2 within inguinal adipocytes in the control of RMR. The AT2 receptor may therefore contribute to body fat distribution and adipose depot-specific effects upon cardio-metabolic health.

Adipose-derived stem cell differentiation as a basic tool for vascularized adipose tissue engineering

The development of in vitro adipose tissue constructs is highly desired to cope with the increased demand for substitutes to replace damaged soft tissue after high graded burns, deformities or tumor removal. To achieve clinically relevant dimensions, vascularization of soft tissue constructs becomes inevitable but still poses a challenge. Adipose-derived stem cells (ASCs) represent a promising cell source for the setup of vascularized fatty tissue constructs as they can be differentiated into adipocytes and endothelial cells in vitro and are thereby available in sufficiently high cell numbers. This review summarizes the currently known characteristics of ASCs and achievements in adipogenic and endothelial differentiation in vitro. Further, the interdependency of adipogenesis and angiogenesis based on the crosstalk of endothelial cells, stem cells and adipocytes is addressed at the molecular level. Finally, achievements and limitations of current co-culture conditions for the construction of vascularized adipose tissue are evaluated.

Comprehensive Review of Adipose Stem Cells and Their Implication in Distraction Osteogenesis and Bone Regeneration

Bone is one of the most dynamic tissues in the human body that can heal following injury without leaving a scar. However, in instances of extensive bone loss, this intrinsic capacity of bone to heal may not be sufficient and external intervention becomes necessary. Several techniques are available to address this problem, including autogenous bone grafts and allografts. However, all these techniques have their own limitations. An alternative method is the technique of distraction osteogenesis, where gradual and controlled distraction of two bony segments after osteotomy leads to induction of new bone formation. Although distraction osteogenesis usually gives satisfactory results, its major limitation is the prolonged duration of time required before the external fixator is removed, which may lead to numerous complications. Numerous methods to accelerate bone formation in the context of distraction osteogenesis have been reported. A viable alternative to autogenous bone grafts for a source of osteogenic cells is mesenchymal stem cells from bone marrow. However, there are certain problems with bone marrow aspirate. Hence, scientists have investigated other sources for mesenchymal stem cells, specifically adipose tissue, which has been shown to be an excellent source of mesenchymal stem cells. In this paper, the potential use of adipose stem cells to stimulate bone formation is discussed.

Understanding the effects of mature adipocytes and endothelial cells on fatty acid metabolism and vascular tone in physiological fatty tissue for vascularized adipose tissue engineering

Engineering of large vascularized adipose tissue constructs is still a challenge for the treatment of extensive high-graded burns or the replacement of tissue after tumor removal. Communication between mature adipocytes and endothelial cells is important for homeostasis and the maintenance of adipose tissue mass but, to date, is mainly neglected in tissue engineering strategies. Thus, new co-culture strategies are needed to integrate adipocytes and endothelial cells successfully into a functional construct. This review focuses on the cross-talk of mature adipocytes and endothelial cells and considers their influence on fatty acid metabolism and vascular tone. In addition, the properties and challenges with regard to these two cell types for vascularized tissue engineering are highlighted.

Fast-proliferating adipose tissue mesenchymal-stromal-like cells for therapy

Human mesenchymal stromal cells, whether from the bone marrow or adipose tissue (hASCs), are promising cell therapy agents. However, generation of abundant cells for therapy remains to be a challenge, due to the need of lengthy expansion and the risk of accumulating genomic defects during the process. We show that hASCs can be easily induced to a reversible fast-proliferating phenotype (FP-ASCs) that allows rapid generation of a clinically useful quantity of cells in <2 weeks of culture. Expanded FP-ASCs retain their finite expansion capacity and pluripotent properties. Despite the high proliferation rate, FP-ASCs show genomic stability by array-comparative genomic hybridization, and did not generate tumors when implanted for a long time in an SCID mouse model. Comparative analysis of gene expression patterns revealed a set of genes that can be used to characterize FP-ASCs and distinguish them from hASCs. As potential candidate therapeutic agents, FP-ASCs displayed high vasculogenic capacity in Matrigel assays. Moreover, application of hASCs and FP-ASCs in a fibrin scaffold over a myocardium infarct model in SCID mice showed that both cell types can differentiate to endothelial and myocardium lineages, although FP-ASCs were more potent angiogenesis inducers than hASCs, at promoting myocardium revascularization.

Adipose-derived stem cells: Implications in tissue regeneration

Adipose-derived stem cells (ASCs) are mesenchymal stem cells (MSCs) that are obtained from abundant adipose tissue, adherent on plastic culture flasks, can be expanded in vitro, and have the capacity to differentiate into multiple cell lineages. Unlike bone marrow-derived MSCs, ASCs can be obtained from abundant adipose tissue by a minimally invasive procedure, which results in a high number of cells. Therefore, ASCs are promising for regenerating tissues and organs damaged by injury and diseases. This article reviews the implications of ASCs in tissue regeneration.

Choosing the right type of serum for different applications of human adipose tissue-derived stem cells: influence on proliferation and differentiation abilities

BACKGROUND AIMS

Adipose tissue-derived stem cells (ADSCs) are thought to have great potential in regenerative medicine. A xenoprotein-free culture and handling system is desirable. To date, there is only little and contradictory information about the influence of the different types of human serum on ADSC proliferation and differentiation.

METHODS

First, ADSCs were cultured in media containing regular human serum (HS plus) or fetal calf serum (FCS plus) with supplementation of growth factors for three passages. During passage 4, ADSC proliferative activity and adipogenic, osteogenic and chondrogenic differentiation ability was quantified. Second, ADSCs were cultured with three different human sera (regular human serum [HS], human serum from platelet-poor plasma [SPPP] or human serum from platelet-rich plasma [SPRP]) without supplementation of platelet-derived growth factor and assessed accordingly. The growth factor content of the different types of human sera was determined by means of multiplex protein assay and enzyme-linked immunosorbent assay.

RESULTS

The different sera did not affect ADSC doubling time significantly (P < 0.05). Specific glycerol-3-phosphat-dehydrogenase activity was significantly lower in cultures with SPRP (P < 0.01) compared with the other media compositions. Extracellular calcium deposition was significantly higher in cells differentiated in cultures with HS or SPPP compared with those with SPRP, HS plus or FCS (P < 0.01). Glycosaminoglycan content and collagen 2 were highest in cells cultured with SPRP (P < 0.001).

CONCLUSIONS

Culturing ADSCs in human serum appears to be a reasonable and efficient alternative compared with FCS. With respect to the outcome of a sighted clinical application, it appears to be feasible to handle the cells in a serum suitable for the intended later use.

The protective effects of breastfeeding on chronic non-communicable diseases in adulthood: A review of evidence

Chronic non-communicable diseases (NCDs), including cardiovascular diseases, cancers, chronic respiratory diseases, diabetes, etc., are the major causes of mortality in the world, notably in low- and middle-income countries. A growing body of evidence suggests that NCDs have a complex etiology resulting from the interaction of genetic factors, gender, age, ethnicity, and the environmental factors. It is well-documented that chronic diseases in adulthood origins in early life. In recent years, much attention has been focused on primordial and primary prevention of NCD risk factors. There are many biological and epidemiological studies on beneficial effects of breastfeeding during infancy on chronic diseases in adulthood, particularly on hypertension, obesity, diabetes, hypercholesterolemia, and cardiovascular diseases. This review article aims to summarize the current literature on the long-term effects of breastfeeding on prevention of NCDs and their risk factors.

The current literature is controversial about these effects; however, a growing body of evidence suggests that breastfeeding has protective roles against obesity, hypertension, dyslipidemia, and type II diabetes mellitus during adulthood. In addition to its short-term benefits, encouraging breastfeeding can have long-term beneficial health effects at individual and population levels.

Effects of epidermal growth factor and basic fibroblast growth factor on the proliferation and osteogenic and neural differentiation of adipose-derived stem cells

Stem cells used for clinical tissue regeneration therapy should have the capacity of self-renewal, high proliferation, and differentiation and be able to be transplanted in large numbers. Although high concentrations of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) may induce the differentiation of stem cells, these factors have been widely used to enhance the propagation of stem cells, including adipose-derived mesenchymal stem cells (ASCs). However, the effects of low concentrations of EGF and bFGF on stem cells need to be evaluated carefully. This study illustrates that low concentrations of EGF (5 ng/mL) and bFGF (10 ng/mL) increase the proliferative ability of ASCs and induce the typical spindle-shaped cell morphology. EGF and bFGF added to medium promoted neural lineage differentiation and impaired the mesodermal differentiation ability of ASCs. This study demonstrates that even low concentrations of EGF and bFGF may limit the differentiation ability of stem cells during stem cell expansion in vitro. EGF and bFGF supplementation should be carefully considered in stem cells for clinical applications.

Harvest site influences the growth properties of adipose derived stem cells

The therapeutic potential of adult stem cells may become a relevant option in clinical care in the future. In hand and plastic surgery, cell therapy might be used to enhance nerve regeneration and help surgeons and clinicians to repair debilitating nerve injuries. Adipose-derived stem cells (ASCs) are found in abundant quantities and can be harvested with a low morbidity. In order to define the optimal fat harvest location and detect any potential differences in ASC proliferation properties, we compared biopsies from different anatomical sites (inguinal, flank, pericardiac, omentum, neck) in Sprague-Dawley rats. ASCs were expanded from each biopsy and a proliferation assay using different mitogenic factors, basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) was performed. Our results show that when compared with the pericardiac region, cells isolated from the inguinal, flank, omental and neck regions grow significantly better in growth medium alone. bFGF significantly enhanced the growth rate of ASCs isolated from all regions except the omentum. PDGF had minimal effect on ASC proliferation rate but increases the growth of ASCs from the neck region. Analysis of all the data suggests that ASCs from the neck region may be the ideal stem cell sources for tissue engineering approaches for the regeneration of nervous tissue.

Modulation of the transcriptional activity of peroxisome proliferator-activated receptor gamma by protein-protein interactions and post-translational modifications

Peroxisome proliferator-activated receptor gamma (PPARγ) belongs to a nuclear receptor superfamily; members of which play key roles in the control of body metabolism principally by acting on adipose tissue. Ligands of PPARγ, such as thiazolidinediones, are widely used in the treatment of metabolic syndromes and type 2 diabetes mellitus (T2DM). Although these drugs have potential benefits in the treatment of T2DM, they also cause unwanted side effects. Thus, understanding the molecular mechanisms governing the transcriptional activity of PPARγ is of prime importance in the development of new selective drugs or drugs with fewer side effects. Recent advancements in molecular biology have made it possible to obtain a deeper understanding of the role of PPARγ in body homeostasis. The transcriptional activity of PPARγ is subject to regulation either by interacting proteins or by modification of the protein itself. New interacting partners of PPARγ with new functions are being unveiled. In addition, post-translational modification by various cellular signals contributes to fine-tuning of the transcriptional activities of PPARγ. In this review, we will summarize recent advancements in our understanding of the post-translational modifications of, and proteins interacting with, PPARγ, both of which affect its transcriptional activities in relation to adipogenesis.

Maintenance of high proliferation and multipotent potential of human hair follicle-derived mesenchymal stem cells by growth factors

Cell therapy and cell-based tissue engineering is becoming increasingly important in regenerative medicine. Stem cells that are characterized by self-renewal, high proliferation and multiple differentiation potentials have attracted attention in cell-based regenerative medicine. Maintaining the aforementioned characteristics of stem cells is the first key step in cell-based regenerative medicine. Basic fibroblast growth factor (bFGF) is a well-known growth factor that efficiently maintains the self-renewal, high proliferation and multilineage differentiation potential of stem cells. Whether or not other growth factors, such as acidic fibroblast growth factor (aFGF) and epidermal growth factor (EGF) have similar effects has yet to be fully elucidated. Human hair follicle-derived mesenchymal stem cells (HF-MSCs) were obtained by organ culture. They exhibited surface markers of bone marrow mesenchymal stem cells as shown by positive staining for CD44, CD73, CD90 and CD105, and they also displayed trilineage differentiation potentials into adipocytes, chondrocytes and osteoblasts by cytochemistry and qRT-PCR. Flow cytometry analysis showed that up to 70% of HF-MSCs cultured in the presence of aFGF, bFGF or EGF stayed at the G0/G1 phase. Proliferation analysis showed that both bFGF and EGF at as low as 1 ng/ml and aFGF at above 5 ng/ml levels significantly increased the proliferation of HF-MSCs by cell counting. Consistent with proliferation analysis, immunofluorescence staining showed that more than 95% of HF-MSCs cultured in the presence of aFGF, bFGF and EGF were positively stained for proliferating cell nuclear antigen. HF-MSCs cultured in the presence of aFGF, bFGF or EGF retained marked trilineage differentiation potentials. By contrast, HF-MSCs cultured in the absence of bFGF, aFGF and EGF lost multipotency.

Growth and positioning of adipose-derived stem cells in microfluidic devices

Stem cells hold great promise for treatment of various degenerative diseases. However, clinical studies have only shown very moderate benefits of cell therapy. We believe that insufficiency of therapeutic benefits is due to limited homing of implanted stem cells to targeted organs. Microfluidic devices are a very useful research tool for quantitative characterizations of stem cells. The present study therefore was to assess the effects of epidermal growth factor (EGF) and direct current electric field (dcEF) on the growth and trafficking of adipose-derived stem cells (ASC). It was found that EGF did not affect cell proliferation in cell-culture flasks. However, ASC proliferated at a higher rate in microfluidic devices with continuous infusion of EGF. Furthermore, we found that ASC migrated toward an EGF gradient in microfluidic devices. Moreover, we found that ASC tended to position perpendicularly to dcEF. The results suggest that EGF and dcEF may be effective in guiding homing and trafficking of implanted ASC.

Simple and longstanding adipose tissue engineering in rabbits

Adipose tissue engineering for breast reconstruction can be performed for patients who have undergone breast surgery. We have previously confirmed adipogenesis in mice implanted with type I collagen sponge with controlled release of fibroblast growth factor 2 (FGF2) and human adipose tissue-derived stem cells. However, in order to use this approach to treat breast cancer patients, a large amount of adipose tissue is needed, and FGF2 is not readily available. Thus, we aimed to regenerate large amounts of adipose tissue without FGF2 for a long period. Under general anesthesia, cages made of polypropylene mesh were implanted into the rabbits' bilateral fat pads. Each cage was 10 mm in radius and 10 mm in height. Minced type I collagen sponge was injected as a scaffold into the cage. Regenerated tissue in the cage was examined with ultrasonography, and the cages were harvested 3, 6, and 12 months after the implantation. Ultrasonography revealed a gradually increasing homogeneous high-echo area in the cage. Histology of the specimen was assessed with hematoxylin and eosin staining. The percentages of regenerated adipose tissue area were 76.2 ± 13.0 and 92.8 ± 6.6 % at 6 and 12 months after the implantation, respectively. Our results showed de novo adipogenesis 12 months after the implantation of only type I collagen sponge inside the space. Ultrasonography is a noninvasive and useful method of assessing the growth of the tissue inside the cage. This simple method could be a promising clinical modality in breast reconstruction.

Adipose tissue engineering with cells in engineered matrices

Tissue engineering has shown promise for the development of constructs to facilitate large volume soft tissue augmentation in reconstructive and cosmetic plastic surgery. This article reviews the key progress to date in the field of adipose tissue engineering. In order to effectively design a soft tissue substitute, it is critical to understand the native tissue environment and function. As such, the basic physiology of adipose tissue is described and the process of adipogenesis is discussed. In this article, we have focused on tissue engineering using a cell-seeded scaffold approach, where engineered extracellular matrix substitutes are seeded with exogenous cells that may contribute to the regenerative response. The strengths and limitations of each of the possible cell sources for adipose tissue engineering, including adipose-derived stem cells, are detailed. We briefly highlight some of the results from the major studies to date, involving a range of synthetic and naturally derived scaffolds. While these studies have shown that adipose tissue regeneration is possible, more research is required to develop optimized constructs that will facilitate safe, predictable and long-term augmentation in clinical applications.

Mimicking the functional niche of adipose-derived stem cells for regenerative medicine

INTRODUCTION

A stem cell (SC) niche is defined as the microenvironment in which the adult SC resides and includes surrounding cells, low oxygen content and growth factor gradients. Crosstalk between SCs and their niche provides signals that keep SCs quiescent, or modulates their activation.

AREAS COVERED

This review discusses the characterization of niche conditions in the adipose-derived stem cell (ASC) in vivo environment, and introduces key signalling pathways and autocrine/paracrine regulators of ASCs.

EXPERT OPINION

Control of in vivo niche factors (such as low oxygen content, generation of reactive oxygen species and activation of platelet-derived growth factor receptor signalling) should increase ASC yields synergistically and reduce production costs. Additionally, the preconditioning of ASCs with these niche factors prior to transplantation might enhance their regenerative potential. ASC niche is complex, and there are components of the niche that we may not yet understand. Therefore, future research needs to focus on identifying the key regulatory factors of the ASC niche in vivo, and developing a novel method to mimic these niche factors for in vitro manipulation.

Effects of multiple agents on epithelial differentiation of rabbit adipose-derived stem cells in 3D culture

Mesenchymal stem cells have been given particular attention in tissue regeneration research due to their multipotency and proliferative activity. In this study, we investigated the possibility of epithelial differentiation of rabbit adipose-derived stem cells (rASCs) in an in vitro 3D culture system. The experimental procedure was performed with different contributing factors including all-trans retinoic acid (ATRA), epidermal growth factor (EGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), and hydrocortisone in air-liquid interface culture, for modulating proliferation and providing a synergistic effect on epithelial differentiation of rASCs. After induction, immunofluorescence staining, western blot analysis, flow cytometry analysis, and quantitative real-time polymerase chain reaction assay have been performed to detect the expression of epithelial-specific markers and mesenchymal marker alpha-smooth muscle actin (α-SMA). The growth pattern and viability of cells were evaluated by transmission electron microscopy and Hoechst 33258 assay, respectively. After treated with optimized induction medium (including 2.5 μM ATRA, 20 ng/mL EGF, 10 ng/mL KGF, 10 ng/mL HGF, and 0.5 μg/mL hydrocortisone), rASCs were observed to display a stratified epithelial-like morphology, with the expression of cytokeratin 19 and cytokeratin 13 in 63.69%±2.63% and 22.17%±1.51%, respectively, and the relative expression level of cytokeratin 19 increased to 3.152 compared with 0.151 before induction. The expression of α-SMA decreased to 19.40%±1.45% after induction, but almost no expression of involucrin was detected. The results showed that the establishment of an epithelial-specific microenvironment may be a feasible way for epithelial differentiation of ASCs in vitro, and provided an alternative for research on epithelium regeneration.

The dietary fatty acid 10E12Z-CLA induces epiregulin expression through COX-2 dependent PGF(2α) synthesis in adipocytes

Conjugated linoleic acids (CLAs) are a group of dietary fatty acids that are widely marketed as weight loss supplements. The isomer responsible for this effect is the trans-10, cis-12 CLA (10E12Z-CLA) isomer. 10E12Z-CLA treatment during differentiation of 3T3-L1 adipocytes induces expression of prostaglandin-endoperoxide synthase-2 (Cyclooxygenase-2; COX-2). This work demonstrates that COX-2 is also induced in fully differentiated 3T3-L1 adipocytes after a single treatment of 10E12Z-CLA at both the mRNA (20-40 fold) and protein level (7 fold). Furthermore, prostaglandin (PG)F(2α), but not PGE(2), is significantly increased 10 fold. In female BALB/c mice fed 0.5% 10E12Z-CLA for 10 days, COX-2 was induced in uterine adipose (2 fold). In vitro, pharmacological COX-2 inhibition did not block the effect of 10E12Z-CLA on adipocyte-specific gene expression although PGF(2α) was dose-dependently decreased. These studies demonstrate that PGF(2α) was not by itself responsible for the reduction in adipocyte character due to 10E12Z-CLA treatment. However, PGF(2α), either exogenously or endogenously in response to 10E12Z-CLA, increased the expression of the potent mitogen and epidermal growth factor (EGF) receptor (EGFR) ligand epiregulin in 3T3-L1 adipocytes. Blocking PGF(2α) signaling with the PGF(2α) receptor (FP) antagonist AL-8810 returned epiregulin mRNA levels back to baseline. Although this pathway is not directly responsible for adipocyte dependent gene expression, these results suggest that this signaling pathway may still have broad effect on the adipocyte and surrounding cells.

EGF receptor (ERBB1) abundance in adipose tissue is reduced in insulin-resistant and type 2 diabetic women

CONTEXT

Indications of adipose tissue dysfunction correlate with systemic insulin resistance and type 2 diabetes. It has been suggested that a defect in adipose tissue turnover may be involved in the development of these disorders. Whether this dysfunction causes or exacerbates systemic insulin resistance is not fully understood. OBJECTIVES, PARTICIPANTS, AND MEASURES: We tested whether the expression of members of the mitogenic ErbB family was reduced in adipose tissue of insulin-resistant individuals and whether ErbB1 and ErbB2 were involved in adipogenesis. Thirty-two women covering a wide range of body mass index values and insulin sensitivity participated in the cross-sectional portion of this study. We also studied preadipocytes isolated from 12 insulin-sensitive individuals to evaluate the impact of ErbB1 or ErbB2 inhibition on adipogenesis in vitro. For this purpose, we measured phospho-ErbB1 and phospho-ErbB2 levels using ELISA and the expression of peroxisome proliferator-activated receptor γ (PPARγ) and PPARγ-regulated genes by real-time PCR.

RESULTS

Among the ErbB family members, only ErbB1 expression was correlated with insulin sensitivity. Additionally, ErbB1 levels correlated positively with PPARγ and several PPARγ-regulated genes including acyl-coenzyme A synthetase long-chain family member 1 (ACSL1), adiponectin, adipose tissue triacylglycerol lipase (ATGL), diacylglycerol acyl transferase 1 (DGAT1), glycerol-3-phosphate dehydrogenase 1 (GPD1), and lipoprotein lipase (LPL), but negatively with CD36 and fatty acid-binding protein 4 (FABP4). In preadipocyte culture, ErbB1, but not ErbB2, inhibition was associated with a reduction in the expression of all the above-mentioned genes.

CONCLUSIONS

These findings demonstrate a key role for ErbB1 in adipogenesis and suggest that lower ErbB1 protein abundance may lead to adipose tissue dysfunction.

Primary culture of human adipocyte precursor cells: expansion and differentiation

Culture of adipose tissue precursor cells allows gaining insight into the sequential processes involved in adipocyte development. Furthermore, the secretory properties associated with these cellular changes can be studied. Although clonal cell lines are valuable tools for the identification of mechanisms associated with proliferation or differentiation such models do not necessarily represent the complexity of adipose tissue physiology. Primary cell culture systems may be closer to physiology and circumvent some of these restrictions. One advantage is that phenotypic properties of the tissue donor such as gender, age, or body weight are still, at least partially retained in vitro. In primary culture, also differences between various adipose depots can be studied either as a condition per se or in the cellular context of the stromal-vascular (SV) fraction. Furthermore, artificial stressors such as hypoxia and other relevant conditions can be applied to elucidate their functional role. Finally, cultures of human adipose precursor cells may also be used as a screening tool for potential novel drug targets to modulate adipocyte differentiation and biology.

Breastfeeding and body composition in children: will there ever be conclusive empirical evidence for a protective effect against overweight?

An increased prevalence of childhood overweight has been observed worldwide over the past decades, which indicates the need for strategies to prevent obesity. There is some evidence that risk of obesity is primed by exposures early in life. Among other factors, breastfeeding has been hypothesized as a potential priming factor against overweight. Although the properties of human milk suggest possible mechanisms for a protective effect of breastfeeding compared with formula feeding with respect to later overweight, empirical evidence is more difficult to establish. This article reviews the available epidemiologic literature on this topic. Several observational studies have shown evidence for a small protective effect with respect to overweight in childhood. Three meta-analyses reported significant protective effects of breastfeeding against overweight in later life, whereas another meta-analysis showed no effect of breastfeeding on mean body mass index (BMI) after adjustment for confounding factors. These seemingly inconsistent results might potentially be explained by different effects of breastfeeding in normal-weight compared with overweight children. Evidence from interventional studies is limited. A randomized trial failed to confirm an effect of a breastfeeding promotion on children's BMI, but this trial lacked statistical power because rates of breastfeeding were relatively similar in the intervention and control groups. In conclusion, protective priming effects of breastfeeding on later overweight appear to be possible but are difficult to prove. Although observational studies have to deal with confounding issues, interventional studies on breastfeeding promotion may lack power.

Chronic disease and infant nutrition: is it significant to public health?

OBJECTIVE

To assess the public health significance of premature weaning of infants from breast milk on later-life risk of chronic illness.

DESIGN

A review and summary of recent meta-analyses of studies linking premature weaning from breast milk with later-life chronic disease risk is presented followed by an estimation of the approximate exposure in a developed Western country, based on historical breast-feeding prevalence data for Australia since 1927. The population-attributable proportion of chronic disease associated with current patterns of artificial feeding in infancy is estimated.

RESULTS

After adjustment for major confounding variables, current research suggests that the risks of chronic disease are 30-200 % higher in those who were not breast-fed compared to those who were breast-fed in infancy. Exposure to premature weaning ranges from 20 % to 90 % in post-World War II age cohorts. Overall, the attributable proportion of chronic disease in the population is estimated at 6-24 % for a 30 % exposure to premature weaning.

CONCLUSIONS

Breast-feeding is of public health significance in preventing chronic disease. There is a small but consistent effect of premature weaning from breast milk in increasing later-life chronic disease risk. Risk exposure in the Australian population is substantial. Approximately 90 % of current 35-45-year-olds were weaned from breast-feeding by 6 months of age. Encouraging greater duration and exclusivity of breast-feeding is a potential avenue for reducing future chronic disease burden and health system costs.

EGFL6 is increasingly expressed in human obesity and promotes proliferation of adipose tissue-derived stromal vascular cells

With increasing rates of obesity driving the incidence of type 2 diabetes and cardiovascular diseases to epidemic levels, understanding of the biology of adipose tissue expansion is a focus of current research. Identification and characterization of secreted proteins of the adipose tissue could provide further insights into the function of adipose tissue and might help to therapeutically influence the development of obesity and associated metabolic disorders. In the present study, we identified human epidermal growth factor-like domain multiple-6 (EGFL6) as an adipose tissue-secreted protein. EGFL6 expression in human subcutaneous adipose tissue significantly increased with obesity and decreased after weight loss. Further, expression and secretion of EGFL6 increased with in vitro differentiation of human preadipocytes, suggesting that mature adipocytes are the main source of EGFL6. Containing epidermal growth factor (EGF)-like repeats, an Arg-Gly-Asp (RGD) integrin binding motif and a mephrin, A5 protein and receptor protein-tyrosine phosphatase mu (MAM) domain, EGFL6 was suggested to be an extra-cellular matrix protein. Recombinant human EGFL6 protein mediated cell adhesion of human adipose tissue-derived stromal vascular cells (AD-SVC) in an RGD-dependent manner. FACS analyses revealed specific binding of the protein to the cell surface of AD-SVC with the binding being predominantly mediated by the EGF-like repeats. Recombinant EGFL6 enhanced proliferation of human AD-SVC as measured by MTS assay and [(14)C]-thymidine incorporation. These results indicate that human EGFL6 is a paracrine/autocrine growth factor of adipose tissue up-regulated in obesity and potentially involved in the process of adipose tissue expansion and the development of obesity.

Signaling and biological effects of glucagon-like peptide 1 on the differentiation of mesenchymal stem cells from human bone marrow

Glucagon-like peptide 1 (GLP-1) functions as an incretin hormone with antidiabetogenic properties. However, the role of GLP-1 in human bone marrow-derived mesenchymal stem cells (hMSCs), if any, remains unknown. The effects of GLP-1 on hMSCs were tested with regard to cell proliferation, cytoprotection, and cell differentiation into adipocytes. The signaling pathways involved in these processes were also analyzed. Cells were characterized with biochemical and morphological approaches before and after being induced to differentiate into adipocytes. PCNA protein levels were used as a proliferation index, whereas cell apoptosis was studied by deprivation of fetal bovine serum. Isolated hMSCs expressed stem cell markers as well as mRNA and GLP-1 receptor protein. GLP-1 increased the proliferation of hMSCs, which decreased when they were induced to differentiate into adipocytes. This process produced biochemical and morphological changes in cells expressing PPARgamma, C/EBPbeta, AP2, and LPL in a time-dependent pattern. Notably, GLP-1 significantly reduced the expression of PPARgamma, C/EBPbeta, and LPL. These effects were exerted at least through the MEK and PKC signaling pathways. In addition, GLP-1 significantly reduced cell apoptosis. Our data indicate that, in hMSCs, GLP-1 promotes cellular proliferation and cytoprotection and prevents cell differentiation into adipocytes. These latter findings underscore the potential therapeutic role of GLP-1 in preventing the adipocyte hyperplasia associated with obesity and, additionally, could bolster the maintenance of hMSC stores by promoting the proliferation and cytoprotection of undifferentiated hMSC.

Culture effects of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on cryopreserved human adipose-derived stromal/stem cell proliferation and adipogenesis

Previous studies have demonstrated that EGF and bFGF maintain the stem cell properties of proliferating human adipose-derived stromal/stem cells (hASCs) in vitro. While the expansion and cryogenic preservation of isolated hASCs are routine, these manipulations can impact their proliferative and differentiation potential. This study examined cryogenically preserved hASCs (n = 4 donors), with respect to these functions, after culture with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) at varying concentrations (0-10 ng/ml). Relative to the control, cells supplemented with EGF and bFGF significantly increased proliferation by up to three-fold over 7-8 days. Furthermore, cryopreserved hASCs expanded in the presence of EGF and bFGF displayed increased oil red O staining following adipogenic induction. This was accompanied by significantly increased levels of several adipogenesis-related mRNAs: aP2, C/EBPalpha, lipoprotein lipase (LPL), PPARgamma and PPARgamma co-activator-1 (PGC1). Adipocytes derived from EGF- and bFGF-cultured hASCs exhibited more robust functionality based on insulin-stimulated glucose uptake and atrial natriuretic peptide (ANP)-stimulated lipolysis. These findings indicate that bFGF and EGF can be used as culture supplements to optimize the proliferative capacity of cryopreserved human ASCs and their adipogenic differentiation potential.

O desmame precoce afeta o ganho de peso e a composição corporal em camundongos adultos?

OBJETIVO: Avaliar o efeito do desmame precoce sobre o ganho de peso e a composição corporal de camundongos adultos jovens. MÉTODOS: Camundongos Swiss Webster, machos, foram desmamados precocemente (14º dia de vida) ou amamentados até o 21º dia de vida (grupo controle). Após o desmame, os animais foram alimentados com ração elaborada para roedores em crescimento até o 63º dia de vida, quando então foram sacrificados. RESULTADOS: O peso corporal dos animais do grupo desmamado de forma precoce foi significantemente maior no 28º, 35º e no 63º dias de vida em relação ao grupo controle (p<0,05). Porém, o consumo de ração não diferiu entre os grupos. A concentração sérica de proteínas totais, albumina e ferro, bem como a concentração hepática, muscular e cerebral de proteínas, ácido desoxirribonucléico e a relação proteína/ácido ribonucléico, não diferiram significantemente entre os grupos. O grupo desmamado precocemente apresentou maior quantidade absoluta de massa magra, lipídeos, proteínas e cinzas, em comparação ao grupo controle (p<0,05). A quantidade relativa de umidade, lipídeos, massa magra, proteínas e cinzas não diferiu entre os grupos. CONCLUSÃO: O desmame precoce, associado à ingestão de ração elaborada para roedores em crescimento, resultou em aumento do ganho de peso, porém não afetou a composição corporal de camundongos adultos.