Insulin-like growth factor I, growth hormone and insulin in white adipose tissue

Application of legumes in plant-based milk alternatives: a review of limitations and solutions

In recent years, a global shift has been observed toward reducing the consumption of animal-derived foods in favor of healthier and more sustainable dietary choices. This has led to a steady growth in the market for plant-based milk alternatives (PBMAs). Projections suggest that this market will reach a value of USD 69.8 billion by 2030. Legumes, being traditional and nutritious ingredients for PMBAs, are rich in proteins, dietary fibers, and other nutrients, with potential health benefits such as anticancer and cardiovascular disease prevention. In this review, the application of 12 legumes in plant-based milk alternatives was thoroughly discussed for the first time. However, compared to milk, processing of legume-based beverages can lead to deficiencies such as nutritional imbalance, off-flavor, and emulsion stratification. Considering the potential and challenges associated with legume-based beverages, this review aims to provide a scientific comparison between legume-based beverages and cow's milk in terms of nutritional quality, organoleptic attributes and stability, and to summarize ways to improve the deficiencies of legume-based beverages in terms of raw materials and processing method improvements. In conclusion, the legume-based beverage industry will be better enhanced and developed by improving the issues.

Ectopic lipid metabolism in anterior pituitary dysfunction

Over the past decades, adapted lifestyle and dietary habits in industrialized countries have led to a progress of obesity and associated metabolic disorders. Concomitant insulin resistance and derangements in lipid metabolism foster the deposition of excess lipids in organs and tissues with limited capacity of physiologic lipid storage. In organs pivotal for systemic metabolic homeostasis, this ectopic lipid content disturbs metabolic action, thereby promotes the progression of metabolic disease, and inherits a risk for cardiometabolic complications. Pituitary hormone syndromes are commonly associated with metabolic diseases. However, the impact on subcutaneous, visceral, and ectopic fat stores between disorders and their underlying hormonal axes is rather different, and the underlying pathophysiological pathways remain largely unknown. Pituitary disorders might influence ectopic lipid deposition indirectly by modulating lipid metabolism and insulin sensitivity, but also directly by organ specific hormonal effects on energy metabolism. In this review, we aim to I) provide information about the impact of pituitary disorders on ectopic fat stores, II) and to present up-to-date knowledge on potential pathophysiological mechanisms of hormone action in ectopic lipid metabolism.

Associations of GHR, IGF-1 and IGFBP-3 expression in adipose tissue cells with obesity-related alterations in corresponding circulating levels and adipose tissue function in children

Components of the growth hormone (GH) axis, such as insulin-like growth factor-1 (IGF-1), IGF-1 binding protein-3 (IGFBP-3), GH receptor (GHR) and GH-binding protein (GHBP), regulate growth and metabolic pathways. Here, we asked if serum levels of these factors are altered with overweight/obesity and if this is related to adipose tissue (AT) expression and/or increased fat mass. Furthermore, we hypothesized that expression of GHR, IGF-1 and IGFBP-3 is associated with AT function. Serum GHBP levels were increased in children with overweight/obesity throughout childhood, while for IGF-1 levels and the IGF-1/IGFBP-3 molar ratio obesity-related elevations were detectable until early puberty. Circulating levels did not correlate with AT expression of these factors, which was decreased with overweight/obesity. Independent from obesity, expression of GHR, IGF-1 and IGFBP-3 was related to AT dysfunction,and increased insulin levels. Serum GHBP was associated with liver fat percentage and transaminase levels. We conclude that obesity-related elevations in serum GHBP and IGF-1 are unlikely to be caused by increased AT mass and elevations in GHBP are more closely related to liver status in children. The diminished AT expression of these factors with childhood obesity may contribute to early AT dysfunction and a deterioration of the metabolic state.

The acromegaly lipodystrophy

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are essential to normal growth, metabolism, and body composition, but in acromegaly, excesses of these hormones strikingly alter them. In recent years, the use of modern methodologies to assess body composition in patients with acromegaly has revealed novel aspects of the acromegaly phenotype. In particular, acromegaly presents a unique pattern of body composition changes in the setting of insulin resistance that we propose herein to be considered an acromegaly-specific lipodystrophy. The lipodystrophy, initiated by a distinctive GH-driven adipose tissue dysregulation, features insulin resistance in the setting of reduced visceral adipose tissue (VAT) mass and intra-hepatic lipid (IHL) but with lipid redistribution, resulting in ectopic lipid deposition in muscle. With recovery of the lipodystrophy, adipose tissue mass, especially that of VAT and IHL, rises, but insulin resistance is lessened. Abnormalities of adipose tissue adipokines may play a role in the disordered adipose tissue metabolism and insulin resistance of the lipodystrophy. The orexigenic hormone ghrelin and peptide Agouti-related peptide may also be affected by active acromegaly as well as variably by acromegaly therapies, which may contribute to the lipodystrophy. Understanding the pathophysiology of the lipodystrophy and how acromegaly therapies differentially reverse its features may be important to optimizing the long-term outcome for patients with this disease. This perspective describes evidence in support of this acromegaly lipodystrophy model and its relevance to acromegaly pathophysiology and the treatment of patients with acromegaly.

Effect of Folic Acid Supplements on Progesterone Profile and Blood Metabolites of Heat-Stressed Holstein Cows during the Early Stage of Pregnancy

The aim was to elucidate the impact of oral folic acid (FA) supplements on progesterone profile, blood metabolites and biochemical indices of heat-stressed Holstein cows during the early stage of pregnancy. The study lasted from the day of artificial insemination through the end of the fourth week of pregnancy. The first group (CON, n = 17) received 0 μg of FA/kg BW as a control. The second and third groups received oral FA doses of 5 (FA5, n = 19) and 10 (FA10, n = 20) μg kg−1 BW, respectively. At the 2nd and 3rd weeks of pregnancy, the FA10 group had greater progesterone levels than the CON group (p < 0.05). The FA10 group had a greater progesterone level than the FA5 and CON groups at the fourth week of pregnancy (p < 0.01). The FA10 group had higher folate levels than CON group during the first three weeks of pregnancy (p < 0.01). Both FA-supplemented groups had significantly greater serum folates than the CON group by the end of the fourth week of pregnancy (p < 0.01). At the 2nd and 4th weeks of pregnancy, the FA10 group had greater levels of serum glucose and globulin than the CON group (p = 0.028 and 0.049, respectively). Both FA-supplemented groups had greater serum growth hormone (GH) levels at the 4th week of pregnancy (p = 0.020). Additionally, the FA10 group showed significantly higher levels of IGF-1 at the 2nd and 4th week of gestation (p = 0.040 and 0.001, respectively). FA supplementation decreased the levels of non-esterified fatty acid (NEFA) at the 2nd and 4th week of gestation (p = 0.020 and 0.035, respectively). Additionally, the FA10 group showed significantly higher pregnancy-associated glycoprotein (PAG) levels at the 2nd and 4th week of gestation (p = 0.005 and 0.001, respectively). In conclusion, oral FA supplementation (10 mcg kg−1) in the first month of gestation improved the progesterone profile, as well as blood folates, PAG, GH, and IGF-1 concentrations in heat-stressed Holstein cows. These findings could be useful in developing practical strategies to keep dairy cows’ regular reproductive patterns under heat stress conditions.

Development and single laboratory validation of a targeted liquid chromatography-triple quadrupole mass spectrometry-based method for the determination of insulin like growth factor-1 in different types of milk samples

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Bovine insulin growth factor 1 (IGF-1) was estimated in different cow milk samples.

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In house validation of a LC-MS/MS IGF-1 investigation method in milks obtained by different technological treatments.

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Development of a sample treatment for the extraction of IGF-1 from different types of cow milk.

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IGF-1 level in cow’s milk was not dependent form milk technological processing.

A simple and reliable targeted liquid chromatography-electrospray-tandem mass spectrometry (LC-MS/MS) method was developed and validated through the selection of two biomarker peptides for the identification and determination of bovine insulin like growth factor-1 (IGF-1) in milk samples. Two urea-based sample extraction procedures were tested. The validation results provided detection limits at the 1–5 ng IGF-1/mL level as a function of the milk matrix, precision ranged from 3 to 8% and the method accuracy in the different milk matrices was assured. Finally, IGF-1 was measured in milk samples obtained by treatment with eleven different technological processes: IGF-1 concentrations were spread over a wide range from 11.2 ± 0.3 ng/mL to 346 ± 8 ng/mL with a median of 57.0 ± 0.2 ng/mL. The highest amount of IGF-1 was found in fresh whole milk samples and no significant correlation was found between the total milk protein content and the IGF-1 concentration level.

Polymorphism analysis and expression patterns of the IGF1 gene in the Shitou goose

Insulin-like growth factor 1 (IGF1) is one of the endocrine hormones that plays an important role in regulating growth and development of animals. In this study, polymorphism in the 5′UTR and 3′UTR coding region and of the IGF1 gene was detected by DNA sequencing technology, and the abundance of IGF1 mRNA in various tissues at three growth stages of the Shitou goose was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Moreover, the differential expression of IGF1 in various tissues between the Shitou goose and Wuzong goose was revealed. Two single nucleotide polymorphisms (SNPs) were found in the exon3 region of IGF1 in the Shitou goose. IGF1 mRNA was extensively expressed in various tissues of Shitou geese with high abundant expression in the liver, breast muscle and leg muscle at three growth stages. IGF1 mRNA expression showed a trend of first increase and then decrease in the pituitary, liver, subcutaneous fat and abdominal fat tissues, but it decreased in the breast muscle and leg muscle of a Shitou goose with growing age. Expression of IGF1 in the liver, leg muscle and pituitary tissues of the Shitou goose was significantly higher than that of the Wuzong goose. This provides a foundation for further study of regulatory mechanisms of IGF1 in the growth and development of geese.

Induction of the CD24 Surface Antigen in Primary Undifferentiated Human Adipose Progenitor Cells by the Hedgehog Signaling Pathway

In the murine model system of adipogenesis, the CD24 cell surface protein represents a valuable marker to label undifferentiated adipose progenitor cells. Indeed, when injected into the residual fat pads of lipodystrophic mice, these CD24 positive cells reconstitute a normal white adipose tissue (WAT) depot. Unluckily, similar studies in humans are rare and incomplete. This is because it is impossible to obtain large numbers of primary CD24 positive human adipose stem cells (hASCs). This study shows that primary hASCs start to express the glycosylphosphatidylinositol (GPI)-anchored CD24 protein when cultured with a chemically defined medium supplemented with molecules that activate the Hedgehog (Hh) signaling pathway. Therefore, this in vitro system may help understand the biology and role in adipogenesis of the CD24-positive hASCs. The induced cells’ phenotype was studied by flow cytometry, Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR) techniques, and their secretion profile. The results show that CD24 positive cells are early undifferentiated progenitors expressing molecules related to the angiogenic pathway.

Human Adipose Stem Cells (hASCs) Grown on Biodegradable Microcarriers in Serum- and Xeno-Free Medium Preserve Their Undifferentiated Status

Human adipose stem cells (hASCs) are promising candidates for cell-based therapies, but they need to be efficiently expanded in vitro as they cannot be harvested in sufficient quantities. Recently, dynamic bioreactor systems operated with microcarriers achieved considerable high cell densities. Thus, they are a viable alternative to static planar cultivation systems to obtain high numbers of clinical-grade hASCs. Nevertheless, the production of considerable biomass in a short time must not be achieved to the detriment of the cells' quality. To facilitate the scalable expansion of hASC, we have developed a new serum- and xeno-free medium (UrSuppe) and a biodegradable microcarrier (BR44). In this study, we investigated whether the culture of hASCs in defined serum-free conditions on microcarriers (3D) or on planar (2D) cell culture vessels may influence the expression of some marker genes linked with the immature degree or the differentiated status of the cells. Furthermore, we investigated whether the biomaterials, which form our biodegradable MCs, may affect cell behavior and differentiation. The results confirmed that the quality and the undifferentiated status of the hASCs are very well preserved when they grow on BR44 MCs in defined serum-free conditions. Indeed, the ASCs showed a gene expression profile more compatible with an undifferentiated status than the same cells grown under standard planar conditions.

Autophagy participants in the dedifferentiation of mouse 3T3-L1 adipocytes triggered by hypofunction of insulin signaling

Our previous data indicate that both insulin and IGF-1 signallings dysfunction promotes the dedifferentiation of primary human and mouse white adipocytes. Based on the fact that insulin activates mTOR and inhibits autophagy, and autophagy deficiency can inhibit the differentiation of white adipocytes, we speculate that autophagy may be related to the dedifferentiation of white adipocytes. We investigated the underlying mechanism of autophagy during dedifferentiation of mouse 3T3-L1 adipocytes. After incomplete inhibition of insulin and IGF-1 signallings, 3T3-L1 adipocytes manifest dedifferentiation accompanied with an increase of autophagy level. If induction only of autophagy in the adipocytes, then the cells also occur somewhat dedifferentiation, and with a slight decrease of insulin signal, while its degree was weaker than insulin signal inhibited cells. Notably, after inhibition of the insulin and IGF-1 signallings and simultaneously inducing autophagy, the dedifferentiation of 3T3-L1 adipocytes was the most obvious compared with other groups, and the insulin and IGF-1 signallings decreases was greater than the cells with inhibition only of insulin signalling. If inhibition of both insulin signal and autophagy simultaneously, the dedifferentiation of the adipocytes reveals similar tendencies to the cells that insulin signal was inhibited. No significant dedifferentiation occurs of 3T3-L1 cells if only inhibition of autophagy. Taken all together, in this study, we proved that autophagy is positively related to the dedifferentiation of 3T3-L1 adipocytes and is regulated through the insulin-PI3K-AKT-mTOCR1-autophagy pathway. Autophagy may also has a certain degree of negative feedback affect on the insulin signalling of 3T3-L1 cells. Our work may help to better understand the biological properties of mature adipocytes and may help formulate anti-obesity strategies by regulating insulin and insulin signaling level.

Chemically Defined Xeno- and Serum-Free Cell Culture Medium to Grow Human Adipose Stem Cells

Adipose tissue is an abundant source of stem cells. However, liposuction cannot yield cell quantities sufficient for direct applications in regenerative medicine. Therefore, the development of GMP-compliant ex vivo expansion protocols is required to ensure the production of a "cell drug" that is safe, reproducible, and cost-effective. Thus, we developed our own basal defined xeno- and serum-free cell culture medium (UrSuppe), specifically formulated to grow human adipose stem cells (hASCs). With this medium, we can directly culture the stromal vascular fraction (SVF) cells in defined cell culture conditions to obtain hASCs. Cells proliferate while remaining undifferentiated, as shown by Flow Cytometry (FACS), Quantitative Reverse Transcription PCR (RT-qPCR) assays, and their secretion products. Using the UrSuppe cell culture medium, maximum cell densities between 0.51 and 0.80 × 10⁵ cells/cm² (=2.55-4.00 × 10⁵ cells/mL) were obtained. As the expansion of hASCs represents only the first step in a cell therapeutic protocol or further basic research studies, we formulated two chemically defined media to differentiate the expanded hASCs in white or beige/brown adipocytes. These new media could help translate research projects into the clinical application of hASCs and study ex vivo the biology in healthy and dysfunctional states of adipocytes and their precursors. Following the cell culture system developers' practice and obvious reasons related to the formulas' patentability, the defined media's composition will not be disclosed in this study.

Amelioration of pancreatic fat accumulation in Japanese type 2 diabetes patients treated with sodium-glucose cotransporter 2 inhibitors: a retrospective study

Background

Prior reports have suggested that pancreatic fat is related to type 2 diabetes. Sodium‐glucose co‐transporter‐2 (SGLT‐2) inhibitors are expected to reduce ectopic fat accumulation.

Aim

This study assessed the effect of SGLT‐2 inhibitors on pancreatic and liver fat accumulations in patients with type 2 diabetes.

Materials and Methods

Retrospective analyses of indices of pancreatic and liver fat accumulations were conducted in 22 type 2 diabetes outpatients who were receiving SGLT‐2 inhibitors for more than 12 weeks. The differences between the pancreatic (P) or liver (L) and splenic (S) computed tomography values were evaluated.

Results

Fatty pancreas was defined as P−S < −8 Hounsfield Unit (HU), and the number of patients with fatty pancreas was 11 (50%). Fatty pancreas significantly improved after SGLT‐2 inhibitor use (median, −20.8; IQR, −34.8 to −14.3 HU vs. median, −14.6; IQR, −29.5 to −7.8 HU; p = 0.041). Fatty liver was defined as L−S ≤ 3.9 HU, and the number of patients with fatty liver was 11 (50%). Fatty liver significantly improved after SGLT‐2 inhibitor use (median, −4.3; IQR, −23.0 to 3.0 HU vs. median, −0.7; IQR, −5.2 to 6.3 HU; p = 0.016).

Conclusion

Pancreatic fat and liver fat accumulations might be reduced after treatment with SGLT‐2 inhibitors in type 2 diabetes patients with intense cumulative fat depositions in these organs.

Development of a Biodegradable Microcarrier for the Cultivation of Human Adipose Stem Cells (hASCs) with a Defined Xeno- and Serum-Free Medium

Stirred single-use bioreactors in combination with microcarriers (MCs) have established themselves as a technology that has the potential to meet the demands of current and future cell therapeutic markets. However, most of the published processes have been performed using fetal bovine serum (FBS) containing cell culture medium and non-biocompatible MCs. This approach has two significant drawbacks: firstly, the inevitable potential risks associated with the use of FBS for clinical applications; secondly, non-biocompatible MCs have to be removed from the cell suspension before implantation, requiring a step that causes loss of viable cells and adds further costs and complications. This study aimed to develop a new platform based on a chemically defined xeno- and serum-free cell culture medium and biodegradable MC that can support the growth of human adipose stem cells (hASCs) while still preserving their undifferentiated status. A specific combination of components and manufacturing parameters resulted in a MC prototype, called “BR44”, which delivered the desired functionality. MC BR44 allows the hASCs to stick to its surface and grow in a chemically defined xeno- and serum-free medium (UrSuppe). Although the cells’ expansion rate was not as high as with a commercial non-biodegradable standard MC, those cultured on BR44 maintained a better undifferentiated status in both static and dynamic conditions than those cultured on traditional 2D surfaces.

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.

How Fat Grafting Works

Fat grafting has been shown to improve diseased soft issue. Although the mechanism behind fat grafting’s regenerative properties is currently debated, published studies agree that there is an associated vasculogenic effect. A systematic literature review was conducted to elucidate the biochemical pathways responsible for establishing neo-vasculature to grafted fat.

Impact of growth factor content on proliferation of mesenchymal stromal cells derived from adipose tissue

Autologous adipose tissue (AT) transfer has gained widespread acceptance and is used for a broad variety of regenerative clinical indications. It is assumed that the successful outcome of AT transfer essentially depends on the amount of autocrine-generated growth factors (GF). It is supposed that several GF enhance and improve the anatomic and functional integration of the transplanted AT grafts at the site of implantation. In the present study we have investigated for the first time the correlation between the concentration of GF of freshly isolated AT and the proliferation and migration capacity of mesenchymal stroma cells (MSCs) derived from the respective AT sample. We here show that the proliferation and migration capacity of MSCs strongly depends on the GF content of the AT the cells were isolated from but in an inversely proportional manner. The lower the GF content of an AT sample was, the higher was the proliferation and migration capacity of the respective MSC population contained in the AT and vice versa. Furthermore, we found that supplementation with recombinant GFs only in the case of AT samples with low but not with higher growth factor contents led to a significant enhancement of proliferation and migration of the AT-resident MSCs. As we further show, this inefficiency of GFs to enhance MSC proliferation and migration in AT samples with high GF contents indicates a GF-mediated negative feedback mechanism leading to an impaired GF signaling in MSC obtained from those AT samples. Our results might explain why the successful use of AT grafting is frequently limited by low and unpredictable survival rates, and we suggest to use the knowledge of GF content of harvested AT as a predictive clinical parameter for risk assessment of the therapeutic outcome of autologous AT transfer.

Effect of Dietary Folic Acid Supplementation during Pregnancy on Blood Characteristics and Milk Composition of Ewes

The objective of the present study was to investigate the dynamic change of serum parameters and milk composition by dietary FA supplementation with ewes with different litter size from mating to lambing. The ewes were divided into six treatments (TW-CON, TW-F16, TW-F32, TR-CON, TR-F16, TR-F32) according to dietary FA levels (control, CON; 16 or 32 mg·kg^-1 rumen-protect-FA supplementation, F16 and F32) and litter size (twin born, TW; and triplet born, TR). In serum, the concentration of folate increased linearly with dietary FA supplementation (P < 0.05), regardless of the litter size, they showed a quadratic response to gestation progression (P < 0.05). With dietary FA addition, IGFI-I levels significant increased from late gestation to after lambing (P < 0.05), and linearly increased immunoglobulin during the perinatal period (P < 0.05). In colostrum and milk at d 15, the content of folate, lactoferrin, and IgG were affected positively by FA supplementation (P < 0.05). IgG was higher in the TW group than TR in colostrum (P < 0.05), and lactoferrin in TW was lower than TR in milk of d 15 (P < 0.05). FA supplementation increased protein content in colostrum (P < 0.05), while it had no effect on the fat, lactose, and BUN of colostrum and milk of d 15 (P > 0.05). These results suggest that FA supplementation during gestation could regulate maternal blood metabolism and contribute to milk immune composition.

Use of pregnancy-associated plasma protein-A during oocyte in vitro maturation increases IGF-1 and affects the transcriptional profile of cumulus cells and embryos from Nelore cows

Insulin-like growth factor 1 (IGF-1) activity is established by the regulation of IGF binding protein activity, which blocks IGF-1 functions, whereas pregnancy-associated plasma protein-A (PAPP-A) improves IGF-1 bioavailability and facilitates binding to IGF receptors. To further extend our understanding of the effect of exogenous PAPP-A on bovine embryo production, we added this protein during in vitro maturation of cumulus-oocyte complexes (COCs); moreover, we assessed its effects on IGF-1 quantity in the maturation medium, embryonic yield and postwarming survival, blastocyst quality, and transcript abundance. Bovine COCs were matured in a serum-free medium, either with PAPP-A supplementation (100 ng/ml) or without (control). The treatment group produced higher IGF-1 concentrations in the maturation medium; however, showed no difference on cleavage, blastocysts rates, and embryonic survival 3 and 24 hr postcryopreservation. Regarding gene expression, VNN1 was upregulated, whereas AGPAT9, FASN, EGFR, HAS2, and IMPDH1 were downregulated in PAPP-A treated. PAPP-A treated, CPT2, DNMT3A, and TFAM were upregulated, whereas ATF4 and IFITM3 were downregulated. We concluded that although the addition of PAPP-A did not affect embryo yield and blastocyst survival, higher IGF-1 levels may affect embryo competence through differential expression of genes involved in lipid metabolism, oocyte competence, and mitochondrial function.

Insulin-like growth factor axis in pregnancy and gestational diabetes mellitus

The insulin-like growth factor (IGF) is involved in the regulation of growth and metabolism. The aim of this study was to determine selected parameters of IGF system at systemic and local levels [subcutaneous (SAT) and visceral adipose tissue (VAT)] to assess its possible role in gestational diabetes mellitus (GDM). 37 pregnant women (21 with GDM and 16 without GDM) and 15 age-matched non-pregnant females were included in the study. Blood samples were taken in 28-32 and 36-38 weeks of gestation and 6-12 months after delivery. SAT and VAT samples were obtained during delivery or surgery. Compared with non-pregnant women, serum IGF-1 and IGFBP-3 were increased in both groups of pregnant women. IGF-2 was elevated only in GDM women from 36 weeks of gestation culminating 6 months after delivery (p=0.003). Serum IGFBP-3 was increased and IGFBP-4 decreased in GDM women vs. pregnant women without GDM during the whole study (IGFBP-3: p?0.001 for GDM vs. non-GDM; IGFBP-4: p=0.004 for GDM vs. non-GDM). Pregnant women with GDM had decreased mRNA expression of IGF-1, IGF-1R and IGF-2R and IGFBP-4 in VAT and IGF-1R in SAT compared to pregnant women without GDM. Changes in local activity of IGF are associated with the development of GDM.

Insulin Promotes Adipose-Derived Stem Cell Differentiation after Fat Grafting

BACKGROUND

Adipose-derived stem cells are used to enhance fat graft survival. However, their mechanism of action when grafted is controversial. The grafted cells can be replaced by connective tissue or survive at the recipient site and differentiate. Insulin is a powerful agent used to induce their differentiation to adipocytes. The purpose of this study was to elucidate the fate of grafted adipose-derived stem cells in nonvascularized fat grafts with or without insulin.

METHODS

Fat was harvested from a female human donor who had undergone reduction mammaplasty. The authors also isolated and cultured adipose-derived stem cells expressing green fluorescent protein from transgenic Sprague-Dawley rats. Injection of free fat graft, the adipose-derived stem cells, phosphate-buffered saline, and insulin was performed on the four paravertebral points of the back of each mouse (n = 30) as follows: group A (control group) received adipose tissue and phosphate-buffered saline; group B received adipose tissue and adipose-derived stem cells; group C received adipose tissue, adipose-derived stem cells, and phosphate-buffered saline; and group D received adipose tissue, adipose-derived stem cells, and insulin. Green fluorescent protein expression was evaluated using an in vivo imaging system. The volume of transplanted fat was evaluated at 8 weeks after graft with six histologic parameters. The fat graft was immunostained with green fluorescent protein, 4',6-diamidino-2-phenylindole, and perilipin. Statistical analysis was performed using a one-way analysis of variance test.

RESULTS

The fat graft volume was significantly higher in group D (p < 0.05). Histologic examination revealed reduced fibrosis and increased cysts, vacuoles, integrity, and vascularity in group D. The green fluorescent protein and perilipin co-positive area was more apparent in group D compared with groups B and C.

CONCLUSION

Insulin could enhance the survival and differentiation of adipose-derived stem cells in nonvascularized fat grafts.

Diseases of Civilization - Cancer, Diabetes, Obesity and Acne - the Implication of Milk, IGF-1 and mTORC1

Nutrition and food are one of the most complex aspects of human lives, being influenced by biochemical, psychological, social and cultural factors. The Western diet is the prototype of modern dietary pattern and is mainly characterized by the intake of large amounts of red meat, dairy products, refined grains and sugar. Large amounts of scientific evidence positively correlate Western diet to acne, obesity, diabetes, heart disease and cancer, the so-called "diseases of civilization". The pathophysiological common ground of all these pathologies is the IGF-1 and mTORC pathways, which will be disscussed further in this paper.

Evaluation of serum insulin-like growth factor-1 and 26S proteasome concentrations in healthy dogs and dogs with chronic diseases depending on body condition score

In patients suffering from chronic diseases, the objective assessment of metabolic states could be of interest for disease prognosis and therapeutic options. Therefore, the aim of this study was to assess insulin-like growth factor-1 (IGF-1) and 26S proteasome (26SP) in healthy dogs and dogs suffering from chronic diseases depending on their body condition score (BCS) and to examine their potential for objective assessment of anabolic and catabolic states. Serum concentrations of IGF-1, an anabolic hormone, and 26SP, a multiprotein complex which is part of the ubiquitin-proteasome pathway, by which the majority of endogenous proteins including the muscle proteins are degraded, were measured in 21 healthy dogs and 20 dogs with chronic diseases by canine ELISA. The concentrations of IGF-1, 26SP and their ratio (IGF-1/26SP) were set in relationship to the BCS of the dogs. When examining healthy and chronically diseased dogs separately, a positive correlation between IGF-1 and the BCS was observed in the healthy group and a negative correlation between 26SP and the BCS was noted in dogs with chronic diseases. Further, dogs suffering from chronic diseases showed higher 26SP concentrations and lower values for IGF-1/26SP than the healthy dogs. Overall, we detected a negative correlation between 26SP and the BCS and a positive correlation between IGF-1/26SP and the BCS. The results of our study indicate usability of IGF-1 for description of anabolic states, while 26SP could be useful for detection and description of catabolic states. Finally, the ratio IGF-1/26SP seems to be promising for assessment of metabolic states.

MicroRNA-30a-3p is overexpressed in the placentas of patients with preeclampsia and affects trophoblast invasion and apoptosis by its effects on IGF-1

OBJECTIVE

Preeclampsia (PE) affects many women globally and remains a primary cause of neonatal and maternal morbidity and mortality. Aberrant placental microRNA (miRNA) expression might be associated with PE. Previously, 33 PE-related miRNAs, 11 up-regulated and 23 down-regulated, were detected in placentas of women with severe PE when compared with those of normal patients. One of the most up-regulated miRNAs in PE is miR-30a-3p. The predicted target of it is insulin-like growth factor 1 (IGF-1), which has been reported to have a relatively low expression level in PE patients. This study was conducted to determine the aberrant increased of miR-30a-3p in the placentas of women with preeclampsia and to elucidate the target and function of it in trophoblast cells.

STUDY DESIGN

miR-30a-3p expression in placenta tissues was compared between women with preeclampsia (n = 25) and normal pregnant women (n = 20). The miRNA target was studied by in silico and functional assay. The effects of the miRNA were verified by apoptosis assay and invasion assay in the trophoblast cell line.

RESULTS

miR-30a-3p was increased significantly in the placenta of women with preeclampsia when compared to those with normal pregnancies. Luciferase assay confirmed direct regulation of miR-30a-3p on the expression of IGF-1. Forced expression of miR-30a-3p suppressed IGF-1 protein expression in the HTR-8/SVneo cells. The functional assay suggests that the over-expression of miR-30a-3p alter the invasive capacity of JEG-3 cells and induce the apoptosis of HTR-8/SVneo cells (Figure).

CONCLUSION

Expression of miR-30a-3p was significantly increased in the placentas of patients with preeclampsia. miR-30a-3p might be involved in the pathogenesis of preeclampsia by targeting IGF-1 and regulating the invasion and apoptosis of trophoblast cells.

High Expression of STAT3 in Subcutaneous Adipose Tissue Associates with Cardiovascular Risk in Women with Rheumatoid Arthritis

Despite the predominance of female patients and uncommon obesity, rheumatoid arthritis (RA) is tightly connected to increased cardiovascular morbidity. The aim of this study was to investigate transcriptional activity in the subcutaneous white adipose tissue (WAT) with respect to this disproportionate cardiovascular risk (CVR) in RA. CVR was estimated in 182 female patients, using the modified Systematic Coronary Risk Evaluation scale, and identified 93 patients with increased CVR. The overall transcriptional activity in WAT was significantly higher in patients with CVR and was presented by higher serum levels of WAT products leptin, resistin and IL-6 (all, p < 0.001). CVR was associated with high WAT-specific transcription of the signal transducer and activator of transcription 3 (STAT3) and the nuclear factor NF-kappa-B p65 subunit (RELA), and with high transcription of serine-threonine kinase B (AKT1) in leukocytes. These findings suggest Interleukin 6 (IL-6) and leptin take part in WAT-specific activation of STAT3. The binary logistic regression analysis confirmed an independent association of CVR with IL-6 in serum, and with STAT3 in WAT. The study shows an association of CVR with transcriptional activity in WAT in female RA patients. It also emphasizes the importance of STAT3 regulatory circuits for WAT-related CVR in RA.

Muscle Conditional Medium Reduces Intramuscular Adipocyte Differentiation and Lipid Accumulation through Regulating Insulin Signaling

Due to the paracrine effects of skeletal muscle, the lipid metabolism of porcine intramuscular (i.m.) preadipocytes was different from that of subcutaneous (s.c.) preadipocytes. To investigate the development of i.m. preadipocytes in vivo, the s.c. preadipocytes were cultured with muscle conditional cultured medium (MCM) for approximating extracellular micro-environment of the i.m. preadipocytes. Insulin signaling plays a fundamental role in porcine adipocyte differentiation. The expression levels of insulin receptor (INSR) and insulin-like growth factor 1 receptor (IGF-1R) in i.m. Preadipocytes were higher than that in s.c. preadipocytes. The effects of MCM on adipocyte differentiation, lipid metabolism and insulin signaling transdution were verified. MCM induced the apoptosis of s.c. preadipocytes but not of s.c. adipocytes. Moreover, MCM inhibited adipocyte differentiation at pre-differentiation and early stages of differentiation, while the expression levels of INSR and IGF-1R were increased. Furthermore, MCM treatment increased adipocyte lipolysis and fatty acid oxidation through induction of genes involved in lipolysis, thermogenesis, and fatty acid oxidation in mitochondria. Consistent with the above, treatment of s.c. adipocytes with MCM upregulated mitochondrial biogenesis. Taken together, MCM can approximate the muscle micro-environment and reduce intramuscular adipocyte differentiation and lipid accumulation via regulating insulin signaling.

Metabolic recovery of lipodystrophy, liver steatosis, and pancreatic β cell proliferation after the withdrawal of OSI-906

Growth factor signaling via insulin receptor (IR) and IGF-1 receptor (IGF1R) plays several important roles in the pathogenesis of metabolic syndrome and diabetes. OSI-906 (linsitinib), an anti-tumor drug, is an orally bioavailable dual inhibitor of IR and IGF1R. To investigate the recovery from metabolic changes induced by the acute inhibition of IR and IGF1R in adult mice, mice were treated with OSI-906 or a vehicle for 7 days and the results were analyzed on the last day of injection (Day 7) or after 7 or 21 days of withdrawal (Day 14 or Day 28). On day 7, the visceral white fat mass was significantly reduced in mice treated with OSI-906 accompanied by a reduced expression of leptin and an increased expression of the lipolysis-related genes Lpl and Atgl. Interestingly, the lipoatrophy and the observed changes in gene expression were completely reversed on day 14. Similarly, liver steatosis and β cell proliferation were transiently observed on day 7 but had disappeared by day 14. Taken together, these results suggest that this model for the acute inhibition of systemic IR/IGF1R signaling may be useful for investigating the recovery from metabolic disorders induced by impaired growth factor signaling.

Effects of paternal obesity on growth and adiposity of male rat offspring

Emerging evidence suggests that paternal obesity plays an important role in offspring health. Our previous work using a rodent model of diet-induced paternal obesity showed that female offspring from high-fat diet (HFD)-fed fathers develop glucose intolerance due to impairment of pancreatic insulin secretion. Here, we focused on the health outcomes of male offspring from HFD-fed fathers. Male Sprague-Dawley rats (3 wk old) were fed control (CD-F0) or HFD (HFD-F0) for 12 wk before mating with control-fed females. Male offspring were fed control diets for up to 8 wk or 6 mo. Although male offspring from HFD-F0 did not develop any obvious glucose metabolism defects in this study, surprisingly, a growth deficit phenotype was observed from birth to 6 mo of age. Male offspring from HFD-F0 had reduced birth weight compared with CD-F0, followed by reduced postweaning growth from 9 wk of age. This resulted in 10% reduction in body weight at 6 mo with significantly smaller fat pads and skeletal muscles. Reduced circulating levels of growth hormone (GH) and IGF-I were detected at 8 wk and 6 mo, respectively. Expression of adipogenesis markers was decreased in adipose tissue of HFD-F0 offspring at 8 wk and 6 mo, and expression of growth markers was decreased in muscle of HFD-F0 offspring at 8 wk. We propose that the reduced GH secretion at 8 wk of age altered the growth of male offspring from HFD-F0, resulting in smaller animals from 9 wk to 6 mo of age. Furthermore, increased muscle triglyceride content and expression of lipogenic genes were observed in HFD-F0 offspring, potentially increasing their metabolic risk.

Differential Roles of Insulin and IGF-1 Receptors in Adipose Tissue Development and Function

To determine the roles of insulin and insulin-like growth factor 1 (IGF-1) action in adipose tissue, we created mice lacking the insulin receptor (IR), IGF-1 receptor (IGF1R), or both using Cre-recombinase driven by the adiponectin promoter. Mice lacking IGF1R only (F-IGFRKO) had a ∼25% reduction in white adipose tissue (WAT) and brown adipose tissue (BAT), whereas mice lacking both IR and IGF1R (F-IR/IGFRKO) showed an almost complete absence of WAT and BAT. Interestingly, mice lacking only the IR (F-IRKO) had a 95% reduction in WAT, but a paradoxical 50% increase in BAT with accumulation of large unilocular lipid droplets. Both F-IRKO and F-IR/IGFRKO mice were unable to maintain body temperature in the cold and developed severe diabetes, ectopic lipid accumulation in liver and muscle, and pancreatic islet hyperplasia. Leptin treatment normalized blood glucose levels in both groups. Glucose levels also improved spontaneously by 1 year of age, despite sustained lipodystrophy and insulin resistance. Thus, loss of IR is sufficient to disrupt white fat formation, but not brown fat formation and/or maintenance, although it is required for normal BAT function and temperature homeostasis. IGF1R has only a modest contribution to both WAT and BAT formation and function.

Content of Soluble Factors and Characteristics of Stromal Vascular Fraction Cells in Lipoaspirates from Different Subcutaneous Adipose Tissue Depots

BACKGROUND

Although fat grafting has emerged as a major force in plastic, reconstructive, and aesthetic surgery, some questions regarding its reliability and regenerative potential remain unanswered.

OBJECTIVES

The authors examined the influence of three anatomic areas on various lipoaspirate properties to identify the most appropriate harvest site for fat-grafting procedures.

METHODS

Lipoaspirates from 25 healthy patients were harvested from the abdomen, inner thigh, and knee. The authors measured the content of soluble factors in the lipoaspirate followed by the assessment of the yield, adipogenic differentiation, proliferation of stromal vascular fraction (SVF) cells, and the percentage of adipose-derived stem cells (ASC) in the SVF. The results also were correlated with the age and body mass index of the donors.

RESULTS

Lipoaspirates from the abdomen showed significantly higher concentrations of matrix metalloproteinase (MMP)-9 compared with the knee. The content of basic fibroblast growth factor (b-FGF), platelet-derived growth factor (PDGF)-BB, and insulin-like growth factor (IGF)-1 tended to be highest in the abdomen but did not reach statistical significance. Vascular endothelial growth factor (VEGF)-A and bFGF-2 contents both correlated negatively with age in lipoaspirates from at least two different anatomic areas.

CONCLUSIONS

The authors' results indicate that the abdomen may be a slight favorite over the inner thigh and knee because of its richer content of soluble factors. However, because only the difference of MMP-9 content actually reached statistical significance and because no differences in SVF characteristics were observed, a decision primarily based on other criteria appears to be justifiable.

Interaction between Esophageal Squamous Cell Carcinoma and Adipose Tissue in Vitro

Esophageal squamous cell carcinoma (ESCC) develops within the squamous epithelial layer and invades the submucosa to the subadventitia that has adipose tissue (AT). AT seems critical to ESCC progression, but the underlying mechanism is unknown. We aimed to address the association between ESCC and AT in vitro. ESCC cells were cultured on rat or human subcutaneous AT-embedded or -non-embedded collagen gel. AT promoted the growth of ESCC cells and inhibited their apoptosis. AT promoted the expression of the squamous differentiation marker involucrin in ESCC cells. AT accelerated the expression of invasion-related factors in poorly differentiated ESCC cells only. AT promoted the expression of phosphorylated-insulin-like growth factor-1 receptor in ESCC cells, whereas it inhibited that of the human epidermal growth factor receptor 2. Insulin-like growth factor-1, but not leptin, adiponectin, or resistin, promoted and inhibited the growth and apoptosis of ESCC cells, respectively. In turn, ESCC cells decreased the production of these adipokines in AT and the number of preadipocytes and mesenchymal stem cell-like cells, which developed from AT. These results suggest that i) AT may influence the progression of ESCC with increased growth or invasion and decreased apoptosis through insulin-like growth factor-1/insulin-like growth factor-1 receptor signaling, ii) AT may affect human epidermal growth factor receptor 2-targeted therapy; and iii) the cancer cells may affect adipokine production in AT.

Association of a genetic marker at the bovine Janus kinase 2 locus (JAK2/RsaI) with milk production traits of four cattle breeds

In addition to the main components of the somatotrophic axis (GH/GHR/IGF-I/IGF-IR), great importance in the control of growth and development is also attached to the Janus kinase 2 (JAK2) pathway. Induced by the GH/GHR complex, JAK2 activates signal transducer and activator of transcription 5 (STAT5), and in consequence, may be involved in the regulation of expression of insulin-like growth factor I (IGF-I) in the mammary gland. Silent mutation (rs110298451) has been identified within exon 20 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A total of 904 individuals of four dairy or dual-purpose breeds (Polish Holstein-Friesian, Montbeliarde, Simmental and Jersey) were genotyped. A genotypic imbalance in the populations was observed. In the case of dual-purpose breeds (Montbeliarde and Simmental), the frequencies of both alleles were almost equal. In contrary, the JAK2G allele was predominant in the Polish Holstein-Friesian breed while JAK2A allele in Jersey. A pronounced relationship between JAK2/RsaI polymorphism and milk production traits was found where, irrespective of breed and lactation order, the GG genotype was significantly associated with higher milk, protein and fat yields, as compared to the AA genotype. Heterozygous individuals were generally characterised by intermediate values of the analysed milk traits. It can be argued that the JAK2 gene polymorphism is a potential marker for milk production traits. However, due to the fact that rs110298451 SNP does not directly affect amino acid sequence, other association studies involving missense mutation should also be performed.

Early postnatal alteration of body composition in preterm and small-for-gestational-age infants: implications of catch-up fat

The concept of the developmental origins of health and disease is based on studies by Barker et al. They proposed a hypothesis that undernutrition in utero permanently changes the body's structure, function, and metabolism in ways that lead to atherosclerosis and insulin resistance in later life. In addition, profound effects on the extent of body fatness and insulin sensitivity are demonstrated, if there is a "mismatch" between prenatal and postnatal environments. In previous studies, undernutrition in utero has been evaluated simply by birth weight itself or birth weight for gestational age, and the degree of mismatch has been estimated by postnatal rapid weight gain. Recently, we investigated subcutaneous fat accumulation in small-for-gestational-age infants and found that a rapid catch-up in skinfold thickness developed prior to the body weight catch-up. Furthermore, insulin-like growth factor-I and lipoprotein lipase mass concentrations also demonstrate rapid increase during the neonatal period with fat accumulation. Investigating the precise mechanisms of developmental origins of health and disease including mediating metabolic and hormonal factors may provide a new approach to prevent atherosclerosis and insulin resistance. Better management of undernutrition during gestation and neonatal growth during the early postnatal period is an important theme for future health.

Daily patterns and adaptation of the ghrelin, growth hormone and insulin-like growth factor-1 system under daytime food synchronisation in rats

Daytime restricted feeding promotes the re-alignment of the food entrained oscillator (FEO). Endocrine cues which secretion is regulated by the transition of fasting and feeding cycles converge in the FEO. The present study aimed to investigate the ghrelin, growth hormone (GH) and insulin-like growth factor (IGF)-1 system because their release depends on rhythmic and nutritional factors, and the output from the system influences feeding and biochemical status. In a daily sampling approach, rats that were fed ad lib. were compared with rats on a reversed (daytime) and restricted feeding schedule by 3 weeks (dRF; food access for 2 h), also assessing the effect of acute fasting and refeeding. We undertook measurements of clock protein BMAL1 and performed somatometry of peripheral organs and determined the concentration of total, acylated and unacylated ghrelin, GH and IGF-1 in both serum and in its main synthesising organs. During dRF, BMAL1 expression was synchronised to mealtime in hypophysis and liver; rats exhibited acute hyperphagia, stomach distension with a slow emptying, a phase shift in liver mass towards the dark period and decrease in mass perigonadal white adipose tissue. Total ghrelin secretion during the 24-h period increased in the dRF group as a result of elevation of the unacylated form. By contrast, GH and IGF-1 serum concentration fell, with a modification of GH daily pattern after mealtime. In the dRF group, ghrelin content in the stomach and pituitary GH content decreased, whereas hepatic IGF-1 remained equal. The daily patterns and synthesis of these hormones had a rheostatic adaptation. The endocrine adaptive response elicited suggests that it may be associated with the regulation of metabolic, behavioural and physiological processes during the paradigm of daytime restricted feeding and associated FEO activity.

Liver-specific GH receptor gene-disrupted (LiGHRKO) mice have decreased endocrine IGF-I, increased local IGF-I, and altered body size, body composition, and adipokine profiles

GH is an important regulator of body growth and composition as well as numerous other metabolic processes. In particular, liver plays a key role in the GH/IGF-I axis, because the majority of circulating "endocrine" IGF-I results from GH-stimulated liver IGF-I production. To develop a better understanding of the role of liver in the overall function of GH, we generated a strain of mice with liver-specific GH receptor (GHR) gene knockout (LiGHRKO mice). LiGHRKO mice had a 90% decrease in circulating IGF-I levels, a 300% increase in circulating GH, and significant changes in IGF binding protein (IGFBP)-1, IGFBP-2, IGFBP-3, IGFBP-5, and IGFBP-7. LiGHRKO mice were smaller than controls, with body length and body weight being significantly decreased in both sexes. Analysis of body composition over time revealed a pattern similar to those found in GH transgenic mice; that is, LiGHRKO mice had a higher percentage of body fat at early ages followed by lower percentage of body fat in adulthood. Local IGF-I mRNA levels were significantly increased in skeletal muscle and select adipose tissue depots. Grip strength was increased in LiGHRKO mice. Finally, circulating levels of leptin, resistin, and adiponectin were increased in LiGHRKO mice. In conclusion, LiGHRKO mice are smaller despite increased local mRNA expression of IGF-I in several tissues, suggesting that liver-derived IGF-I is indeed important for normal body growth. Furthermore, our data suggest that novel GH-dependent cross talk between liver and adipose is important for regulation of adipokines in vivo.

Bone and fat mass in relation to postnatal levels of insulin-like growth factors in prematurely born children at 4 y of age

BACKGROUND

Children born prematurely may be at risk of developing osteopenia. This study investigated whether insulin-like growth factors (IGFs) in the early postnatal period influence bone mass and body composition in prematurely born children.

METHODS

A total of 74 control (gestational age >36 wk; n = 37) and preterm (gestational age <32 wk; n = 37) infants were investigated (mean age ± SD: 4.59 ± 0.31 y). Bone mineral density, body composition, and markers of bone and mineral metabolism were investigated in relation to postnatal IGF levels.

RESULTS

After adjusting for confounders, we found no differences in bone mass, but significantly less lean mass, increased fat mass, and increased osteocalcin levels in ex-preterm infants. Forward stepwise multiple analysis revealed that higher late postnatal IGF-II levels predict lumbar spine bone mineral content (P < 0.05) and lean mass (P < 0.05). When the birth weight standard deviation score was included in the analysis, higher early postnatal IGF-I levels predicted both lumbar spine bone mineral density and bone mineral content (P < 0.05). Higher early postnatal IGF binding protein-3 (P < 0.01) predicted increased fat mass at 4-y follow-up.

CONCLUSION

Ex-preterm children have normal bone mass but different body composition compared with full-term controls. Higher early IGF-I and late postnatal IGF-II concentrations are positive predictors of lumbar spine bone mass.

Interaction of the endocrine system with inflammation: a function of energy and volume regulation

During acute systemic infectious disease, precisely regulated release of energy-rich substrates (glucose, free fatty acids, and amino acids) and auxiliary elements such as calcium/phosphorus from storage sites (fat tissue, muscle, liver, and bone) are highly important because these factors are needed by an energy-consuming immune system in a situation with little or no food/water intake (sickness behavior). This positively selected program for short-lived infectious diseases is similarly applied during chronic inflammatory diseases. This review presents the interaction of hormones and inflammation by focusing on energy storage/expenditure and volume regulation. Energy storage hormones are represented by insulin (glucose/lipid storage and growth-related processes), insulin-like growth factor-1 (IGF-1) (muscle and bone growth), androgens (muscle and bone growth), vitamin D (bone growth), and osteocalcin (bone growth, support of insulin, and testosterone). Energy expenditure hormones are represented by cortisol (breakdown of liver glycogen/adipose tissue triglycerides/muscle protein, and gluconeogenesis; water retention), noradrenaline/adrenaline (breakdown of liver glycogen/adipose tissue triglycerides, and gluconeogenesis; water retention), growth hormone (glucogenic, lipolytic; has also growth-related aspects; water retention), thyroid gland hormones (increase metabolic effects of adrenaline/noradrenaline), and angiotensin II (induce insulin resistance and retain water). In chronic inflammatory diseases, a preponderance of energy expenditure pathways is switched on, leading to typical hormonal changes such as insulin/IGF-1 resistance, hypoandrogenemia, hypovitaminosis D, mild hypercortisolemia, and increased activity of the sympathetic nervous system and the renin-angiotensin-aldosterone system. Though necessary during acute inflammation in the context of systemic infection or trauma, these long-standing changes contribute to increased mortality in chronic inflammatory diseases.

Abnormal fat distribution in PMM2-CDG

We hypothesize that abnormal fat distribution, a common feature of PMM2-CDG, is associated with abnormal perinatal hormone regulation. We assessed 32 cases with PMM2-CDG, for the comorbidity of hypoglycemia/hyperinsulinism and fat pads. Ninety percent of patients with hypoketotic hypoglycemia and/or hyperinsulinism had abnormal fat distribution, while normoglycemic patients showed this feature in 50% of the cases. This statistically significant difference suggests an etiological role of the insulin receptor in developing abnormal fat distribution in PMM2-CDG.

Preferential impact of pregnancy-associated plasma protein-A deficiency on visceral fat in mice on high-fat diet

Accumulation of visceral fat, more so than subcutaneous fat, is strongly associated with severe metabolic complications. However, the factors regulating depot-specific adipogenesis are poorly understood. In this study, we show differential expression of pregnancy-associated plasma protein-A (PAPP-A), a secreted regulator of local insulin-like growth factor (IGF) action, in adipose tissue of mice. PAPP-A mRNA expression was fivefold higher in visceral (mesenteric) fat compared with subcutaneous (inguinal, subscapular), perirenal, and brown fat of mice. To investigate the possible role of depot-specific PAPP-A expression in fat accumulation, wild-type (WT) and PAPP-A knockout (KO) mice were fed a high-fat diet (HFD) for up to 20 wk. Adipocyte size increased in subcutaneous and perirenal depots similarly in WT and PAPP-A KO mice. However, fat cell size and in vivo lipid uptake were significantly reduced in mesenteric fat of PAPP-A KO compared with WT mice. After 20 wk on HFD, phosphorylation of AKT, a downstream signaling intermediate of IGF-I and insulin receptor activation, was significantly decreased by 50% in mesenteric compared with subcutaneous fat in WT mice, but was significantly increased threefold in mesenteric compared with subcutaneous fat in PAPP-A KO mice. This appeared to be because of enhanced insulin-stimulated signaling in mesenteric fat of PAPP-A KO mice. These data establish fat depot-specific expression of PAPP-A and indicate preferential impact of PAPP-A deficiency on visceral fat in the mouse that is associated with enhanced insulin receptor signaling. Thus, PAPP-A may be a potential target for treatment and/or prevention strategies for visceral obesity and related morbidities.

Characterization and endocrine regulation of proliferation and differentiation of primary cultured preadipocytes from gilthead sea bream (Sparus aurata)

A preadipocyte primary cell culture was established to gain knowledge about adipose tissue development in gilthead sea bream (Sparus aurata), one of the most extensively produced marine aquaculture species in the Mediterranean. The preadipocytes obtained from the stromal-vascular cell fraction of adipose tissue proliferated in culture, reaching confluence around day 8. At that time, the addition of an adipogenic medium promoted differentiation of the cells into mature adipocytes, which showed an enlarged cytoplasm filled with lipid droplets. First, cell proliferation and differentiation were analyzed under control and adipogenic conditions during culture development. Next, the effects of insulin, GH, and IGF-I on cell proliferation were evaluated at day 8. All peptides significantly stimulated proliferation of the cells after 48 h of incubation (P < 0.002 for GH and IGF-I and P < 0.05 for insulin), despite no differences were observed between the different doses tested. Subsequently, the effects of insulin and IGF-I maintaining differentiation when added to growth medium were studied at day 11, after 3 d of induction with adipogenic medium. The results showed that IGF-I is more potent than insulin enhancing differentiation (P < 0.01 for IGF-I compared with the control). In summary, a primary culture of gilthead sea bream preadipocytes has been characterized and the effects of several regulators of growth and development have been evaluated. This cellular system can be a good model to study the process of adipogenesis in fish, which may help improve the quality of the product in aquaculture.

Des-acyl ghrelin analogs prevent high-fat-diet-induced dysregulation of glucose homeostasis

There is clinical evidence that des-acyl ghrelin (DAG) favorably modulates glucose and lipid metabolism, although its mode of action is unknown. A murine model of prediabetes was used to assess possible mechanisms of action for DAG and a newly developed bioactive analog, AZP531. C57BL/6J mice were infused with saline, DAG, or AZP531 continuously for 4 wk, and fed either normal diet (ND) or normal diet for 2 wk followed by a high-fat diet (HFD) for 2 wk. Compared with mice in the ND group, HFD increased body and fat mass, caused glucose intolerance and insulin resistance, had proinflammatory effects in white adipose tissue, and caused lipid accumulation in brown adipose tissue. DAG and AZP531 treatment prevented HFD-induced proinflammatory effects, stimulated expression of mitochondrial function markers in brown adipose tissue, and prevented development of a prediabetic metabolic state. AZP531 also prevented a HFD-induced increase in acyl ghrelin levels. Our data indicate DAG analogs as potential treatment for the prevention of metabolic syndrome.

The production and regulation of IGF and IGFBPs in human adipose tissue cultures

BACKGROUND

Adipocytes express and secrete IGFs and IGFBPs; proteins with important effects on adipocyte homeostasis. However, the factors that control adipocyte generation of IGFs and IGFBPs are not clarified.

AIM

To identify regulators of the synthesis of IGFs and IGFBs in adipose tissue.

METHODS

Subcutaneous adipose tissue fragments (500 mg) from 7 healthy lean women were incubated for 48 h following addition of GH (50 μg/l), dexamethasone (DXM, 20 nM), insulin (100 nM), interleukin (IL)-1β (50 ng/l), IL-6 (50 ng/l) and tumor-necrosis factor (TNF)-α (10 ng/l). Outcome parameters included tissue mRNA and culture media IGF and IGFBP levels.

RESULTS

Adipose tissue cultures secreted more IGF-II than IGF-I protein (1.14±0.41 vs. 0.26±0.09 μg/l [mean±SEM]; P<0.02). IGF-I mRNA and protein levels were stimulated by GH (to 340% [153; 477] (median [interquartiles]) and 270±26%, respectively; P<0.003), and inhibited by IL-1β (to 28% [21; 77] and 68±11%, respectively; P<0.003). TNF-α reduced IGF-I and IGF-II protein levels to 51±8% and 69±8%, respectively (P≤0.002), without affecting mRNA levels. IGF protein levels were unaffected by DXM, insulin and IL-6. All IGFBPs IGFBP-1 were expressed. IGFBP-4 was by far the most predominant IGFBP by immunoassay and WLB revealed two bands at 28 and 24 kDa, most likely representing glycosylated and non-glycosylated IGFBP-4.

CONCLUSION

Adipose tissue cultures secrete more IGF-II than IGF-I, and predominantly IGFBP-4. The secretion of IGF-I is affected by GH, IL-1β and TNF-α, whereas IGF-II is affected by TNF-α only. Hence, cytokines may control adipocyte homeostasis by affecting local IGF-generation.

Serum concentrations and tissue expression of components of insulin-like growth factor-axis in females with type 2 diabetes mellitus and obesity: the influence of very-low-calorie diet

We explored serum concentrations and mRNA expression of insulin-like-growth factor-1 (IGF-1) axis components in subcutaneous adipose tissue (SCAT) and peripheral monocytes (PM) of 18 healthy females, 11 obese non-diabetic females (OB) and 13 obese women with type 2 diabetes (T2DM) examined at baseline and after very-low-calorie diet (VLCD). T2DM women had decreased expression of IGF-1, IGF-1 receptor (IGF-1R), IGFBP-2 (IGF binding protein-2) and IGFBP-3 in SCAT and increased expression of IGF-1R in PM compared to control group. IGF-1R and IGFBP-3 mRNA expression in SCAT of OB was comparable to control group. In T2DM women VLCD increased serum levels and SCAT expression of IGFBP-2 and PM expression of IGFBP-3. We conclude that decreased IGF-1, IGF-1R and IGFBP-3 expression in SCAT and increased IGF-1R expression in PM of T2DM subjects might contribute to changes of fat differentiation capacity and to regulation of subclinical inflammation by PM, respectively. Increased SCAT and circulating IGFBP-2 and IGFBP-3 in PM might participate in metabolic improvements after VLCD.

Comparative transcriptomic and proteomic analyses of Trichomonas vaginalis following adherence to fibronectin

The morphological transformation of Trichomonas vaginalis from an ellipsoid form in batch culture to an adherent amoeboid form results from the contact of parasites with vaginal epithelial cells and with immobilized fibronectin (FN), a basement membrane component. This suggests host signaling of the parasite. We applied integrated transcriptomic and proteomic approaches to investigate the molecular responses of T. vaginalis upon binding to FN. A transcriptome analysis was performed by using large-scale expressed-sequence-tag (EST) sequencing. A total of 20,704 ESTs generated from batch culture (trophozoite-EST) versus FN-amoeboid trichomonad (FN-EST) cDNA libraries were analyzed. The FN-EST library revealed decreased amounts of transcripts that were of lower abundance in the trophozoite-EST library. There was a shift by FN-bound organisms to the expression of transcripts encoding essential proteins, possibly indicating the expression of genes for adaptation to the morphological changes needed for the FN-adhesive processes. In addition, we identified 43 differentially expressed proteins in the proteomes of FN-bound and unbound trichomonads. Among these proteins, cysteine peptidase, glyceraldehyde-3-phosphate dehydrogenase (an FN-binding protein), and stress-related proteins were upregulated in the FN-adherent cells. Stress-related genes and proteins were highly expressed in both the transcriptome and proteome of FN-bound organisms, implying that these genes and proteins may play critical roles in the response to adherence. This is the first report of a comparative proteomic and transcriptomic analysis after the binding of T. vaginalis to FN. This approach may lead to the discovery of novel virulence genes and affirm the role of genes involved in disease pathogenesis. This knowledge will permit a greater understanding of the complex host-parasite interplay.

Generation and characterization of Tmeff2 mutant mice

TMEFF2 is a single-transmembrane protein containing one EGF-like and two follistatin-like domains. Some studies implicated TMEFF2 as a tumor suppressor for prostate and other cancers, whereas others reported TMEFF2 functioning as a growth factor for neurons and other cells. To gain insights into the apparently conflicting roles of TMEFF2, we generated a null allele of Tmeff2 gene by replacing its first coding exon with human placental alkaline phosphatase cDNA (Tmeff2(PLAP)). Tmeff2(PLAP/PLAP) homozygous mutant mice are born normal, but show growth retardation and die around weaning age. Tmeff2 is widely expressed in the nervous system, and the Tmeff2(PLAP) knock-in allele enables the visualization of neuronal innervations of skin and internal organs with a simple alkaline phosphatase staining. Tmeff2 is also highly expressed in prostate gland and white adipose tissues (WAT). However, with the exception of reduced WAT mass, extensive anatomical and molecular analyses failed to detect any structural or molecular abnormalities in the brain, the spinal cord, the enteric nervous system, or the prostate in the Tmeff2 mutants. No tumors were found in Tmeff2-mutant mice. The Tmeff2(PLAP/PLAP) knock-in mouse is an useful tool for studying the in vivo biological functions of TMEFF2.

Impaired thermogenesis and adipose tissue development in mice with fat-specific disruption of insulin and IGF-1 signalling

Insulin and insulin-like growth factor 1 (IGF-1) have important roles in adipocyte differentiation, glucose tolerance and insulin sensitivity. Here to assess how these pathways can compensate for each other, we created mice with a double tissue-specific knockout of insulin and IGF-1 receptors to eliminate all insulin/IGF-1 signalling in fat. These FIGIRKO mice had markedly decreased white and brown fat mass and were completely resistant to high fat diet-induced obesity and age- and high fat diet-induced glucose intolerance. Energy expenditure was increased in FIGIRKO mice despite a >85% reduction in brown fat mass. However, FIGIRKO mice were unable to maintain body temperature when placed at 4 °C. Brown fat activity was markedly decreased in FIGIRKO mice but was responsive to β3-receptor stimulation. Thus, insulin/IGF-1 signalling has a crucial role in the control of brown and white fat development, and, when disrupted, leads to defective thermogenesis and a paradoxical increase in basal metabolic rate.

The insulin-like growth factors in adipogenesis and obesity

Adipose tissue has been recognized as a major target of growth hormone (GH) action. GH was shown to inhibit adipocyte differentiation but stimulated preadipocyte proliferation in vitro. GH acts directly via its receptor or via upregulating insulin-like growth factor (IGF)-I, which is a critical mediator of preadipocyte proliferation, differentiation, and survival. Results from clinical studies on GH treatment in patients with GH deficiency or GH insensitivity syndrome can be used to dissect GH and IGF as well as IGF-binding protein (IGFBP) actions in vivo. In this article, changes of the GH/IGF system during adipocyte differentiation in vitro as well as related signaling pathways and their impact on adipose tissue growth and function are discussed. Clinical considerations include the effects of GH and IGF-I on adipose tissue during treatment of GH deficiency, differences in the IGF system between visceral and subcutaneous adipose tissue depots as well as the recently emerging role for adipose tissue in the regulation of glucose homeostasis.

Excessive Leucine-mTORC1-Signalling of Cow Milk-Based Infant Formula: The Missing Link to Understand Early Childhood Obesity

Increased protein supply by feeding cow-milk-based infant formula in comparison to lower protein content of human milk is a well-recognized major risk factor of childhood obesity. However, there is yet no conclusive biochemical concept explaining the mechanisms of formula-induced childhood obesity. It is the intention of this article to provide the biochemical link between leucine-mediated signalling of mammalian milk proteins and adipogenesis as well as early adipogenic programming. Leucine has been identified as the predominant signal transducer of mammalian milk, which stimulates the nutrient-sensitive kinase mammalian target of rapamycin complex 1 (mTORC1). Leucine thus functions as a maternal-neonatal relay for mTORC1-dependent neonatal β-cell proliferation and insulin secretion. The mTORC1 target S6K1 plays a pivotal role in stimulation of mesenchymal stem cells to differentiate into adipocytes and to induce insulin resistance. It is of most critical concern that infant formulas provide higher amounts of leucine in comparison to human milk. Exaggerated leucine-mediated mTORC1-S6K1 signalling induced by infant formulas may thus explain increased adipogenesis and generation of lifelong elevated adipocyte numbers. Attenuation of mTORC1 signalling of infant formula by leucine restriction to physiologic lower levels of human milk offers a great chance for the prevention of childhood obesity and obesity-related metabolic diseases.