Adipogenesis Markers Research Articles

The Subacromial Bursa is a Viable Source of Autologous Mesenchymal Stem Cells for Rotator Cuff Repair

Objectives: Chronic rotator cuff tears still represent a significant source of morbidity and functional decline in the general population. The purpose of this study was to establish protocols for isolation and expansion of bursa-derived mesenchymal stem cells (BDSCs) and to evaluate their differentiation capacity, including tenogenesis. We hypothesized that BDSCs would be capable of multilineage differentiation (including tenogenesis) and represent an important source for autologous stem cells for patients undergoing rotator cuff repair. Methods: After IRB approval, 10 patients (ages 43-65 years) scheduled to undergo arthroscopic repair for chronic rotator cuff tears were enrolled. During diagnostic arthroscopy, subacromial bursa tissue was harvested using an arthroscopic shaver and collected by attaching the outflow tubing to a specialized specimen cup. Tissue specimens were transported to our laboratory for analysis. BDSCs were isolated via adherent culture and plated in Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% Fetal Bovine Serum (FBS). Chondrogenic, adipogenic, and osteogenic induction media were used to induce differentiation. Tenogenic induction was performed using DMEM supplemented with varying concentrations of BMP-12, ascorbic acid, and human tenocyte-conditioned media. Alcian Blue staining was used to evaluate chondrogenesis, Oil Red O staining for adipogenesis, and Alkaline Phosphatase staining for osteogenesis. Gene expression markers for adipogenesis (ADIPOQ, FABP4, PPARγ), chondrogenesis (COL2A1 and SOX5), and osteogenesis (osteocalcin, osterix), along with primary antibodies to tenogenic markers (scleraxis, tenomodulin), were used to verify each cell lineage. Results: BDSCs isolated by adherent culture without collagen exhibited a spindle-shaped morphology characteristic of mesenchymal stem cells (MSCs), formed colonies, and demonstrated great expandability for six to eight passages without morphology changes (Figure 1A). After 3 weeks of culture, 95% (p<0.0001) of the BDSCs expressed the MSC surface marker CD90 and were negative for non-MSC cell markers (CD45, CD146, CD31, and CD34) (Figure 1B and C). These BDSCs demonstrated a capacity for adipogenesis (positive Oil Red O staining, ADIPOQ, FABP4, PPARγ expression), osteogenesis (positive alkaline phosphatase staining, positive osteocalcin and scleraxis expression), chondrogenesis (positive Alcian Blue staining, positive COL2A1 and SOX5 expression), and tenogenesis (scleraxis and tenomodulin expression) (Figure 2). The results indicate that BDSCs are multipotent as evidenced by their differentiation into fat, bone, cartilage, and tendon cells. For tenogenesis, we found that 7-day incubation in DMEM supplemented with 100 ng/mL of BMP-12 and 50 μg/mL of ascorbic acid produced superior tenogenic induction. These BDSCs adapted an elongated morphology combined with the expression of both scleraxis and tenomodulin - a unique characteristic of native tenocytes. Conclusion: Our results demonstrate that subacromial bursa represents a viable source of mesenchymal stem cells. We developed a reliable protocol for isolation of BDSCs from patient bursa samples. We show that BDSCs in the presence of BMP-12 and ascorbic acid can differentiate toward a tenogenic lineage. Our work provides strong evidence that BDSCs may be a potent tool for cellular therapy and may benefit future patients who undergo surgical repair of chronic rotator cuff tears. [Figure: see text][Figure: see text]

Effects of Bamboo Stem Extracts on Adipogenic Differentiation and Lipid Metabolism Regulating Genes

Diabetes mellitus is a chronic, progressive disease that has lasting effects on several organs and tissues. In addition, high glucose levels, high triglyceride and high cholesterol levels increase patient health problems. In this study, we investigated natural materials that can alleviate diabetes symptoms or prevent its onset and assessed extracts of bamboo stem, which has been known for centuries as a functional food. Mouse 3T3-L1 cells were induced to differentiate by adding a mixture of dexamethasone, 3-isobutyl-1-methylxanthine, and insulin (DMI) to the cell media after cells reached 100% confluence. The cells were then treated with hot water extract (HE), ethanol extract (EE), or methanol extract (ME) of bamboo stem for 4 and 13 days, after which the expression levels of differentiation markers C/EBPβ, PPARγ, and FABP4 were measured. At day 13, changes in metabolic function were assessed by analyzing the expression levels of ABCG1, CD36, and GLUT4 using RT-qPCR. Adipocyte size distribution was determined using a Coulter counter after trypsinization. The total triglyceride content was quantified using an adipogenesis assay kit. The HE-, EE-, and ME-treated 3T3-L1 cells showed increased adipogenesis marker expression, triglyceride content, and adipocyte volumes compared to the controls. The expression of genes related to adipocyte function were elevated in EE- and ME-treated samples. Taken together, these findings indicate that bamboo stem extracts, especially ethanol extract, have prophylactic effects for diabetes that occur through the promotion of adipogenesis and adipocyte functions.

PO-01-077 The effects of testosterone treatment on fat tissue dysfunction and nonalcoholic fatty liver disease in obese men undergoing bariatric surgery

Substitution treatment of hypogonadism in clinical and experimental models has shown beneficial effects on insulin sensitivity and accumulation of visceral and liver fat. Aim of the study was to analyze the effects of testosterone replacement therapy on benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) clinical parameters, adipose tissue dysfunction and nonalcoholic fatty liver disease (NAFLD) in obese patients candidates for bariatric surgery. Patients were divided into three groups: eugonadal, untreated hypogonadal and symptomatic hypogonadal treated for 6-8 months with testosterone. BPH/LUTS parameters were assessed by IPSS (International Prostate Symptom Score) and prostate ultrasound. Preadipocyte cells (hPADs) isolated from adipose tissue biopsies were used to evaluate insulin sensitivity, adipogenic potential and mitochondrial function. NAFLD was evaluated by triglycerides (TG) assay and histological examination of liver biopsies. Clinically, notwithstanding a prostate volume increase, testosterone treatment improved the IPSS score and hyperemia. Liver TG levels correlated positively with both steatosis and NAS scores, and resulted significantly higher in hypogonadal patients when compared to eugonadal patients, with testosterone treatment significantly reducing TG levels. In the liver, testosterone treatment induced an increased mRNA expression of lipid metabolism markers, whereas in visceral adipose tissue it induced an increased mRNA expression of lipid catabolism and mitochondrial biofunctionality markers. In hPADs testosterone treatment induced an increased mRNA expression of brown adipogenesis and mitochondrial biofunctionality markers. Testosterone treatment normalized hPADs ability to respond to increasing concentrations of insulin. Accordingly, glucose uptake AUCs showed a positive correlation with testosterone levels. Hypogonadal hPADs mitochondria displayed a lower average length and a superoxide generation increase, compared to eugonadal, with testosterone treatment normalizing both parameters.

Identification of Long Non-coding RNAs Expressed During Early Adipogenesis

Long non-coding RNAs (lncRNAs) are transcripts with a length of more than 200 nucleotides that lack protein-coding capacity. LncRNAs play important roles in the regulation of genes during many biological processes, development and disease progression, such as obesity. Obesity is an increasing health concern around the world. Although multiple studies linking lncRNAs and fully differentiated adipocytes have been published, the systematic analysis of those lncRNAs involved in early preadipocyte differentiation, when fate determination decisions are made, has not been reported. In order to fill this gap, we conducted strand-specific RNA-Seq on mouse 3T3-L1 preadipocyte cells and compared the expression profiles before and after early differentiation for 2 days. We identified 82 lncRNAs that significantly changed their expression after early differentiation, 98% of which were newly discovered in association with early adipogenesis. The most remarkable lncRNAs were U90926, Wincr1, Kcnq1ot1, Malat1 and Hotairm1. Expression patterns for these identified genes were also highly correlated with markers of adipogenesis, including PPARγ, CEBPα, FABP4 and FASN. Further analysis implies that many of those altered lncRNAs might coordinately inhibit Wnt/β-catenin signaling pathway to promote preadipocyte differentiation. This work strongly suggests that lncRNAs are critical in the proliferation and differentiation of adipose tissue.

Adipose Lipocalin 2 overexpression protects against age-related decline in thermogenic function of adipose tissue and metabolic deterioration

ObjectivesAging increases the risk for development of adipose tissue dysfunction, insulin resistance, dyslipidemia, and liver steatosis. Lipocalin 2 (Lcn2) deficient mice are more prone to diet-induced obesity and metabolic dysfunction, indicating a protective role for Lcn2 in younger mice. In this study, we determined whether overexpressing Lcn2 in adipose tissue can protect against age-related metabolic deterioration. MethodsWe developed ap2-promoter-driven Lcn2 transgenic (Tg) mice and aged Lcn2 Tg mice for the metabolic assessments. ResultsWe found decreased adipocyte size in inguinal white adipose tissue (iWAT) from 10-month-old Lcn2 Tg mice relative to WT. This was accompanied by increased markers of adipogenesis in iWAT and attenuation of the age-related decline in AMP-activated protein kinase (AMPK) phosphorylation in adipose tissue depots. In addition to improvements in adipose tissue function, whole-body metabolic homeostasis was maintained in aged Lcn2 Tg mice. This included improved glucose tolerance and reduced serum triglycerides in older Lcn2 Tg mice relative to WT mice. Further, liver morphology and liver lipid levels were improved in older Lcn2 Tg mice, alongside a decrease in markers of liver inflammation and fibrosis. ConclusionsWe demonstrate that overexpression of Lcn2 in adipose tissue not only preserves adipose tissue function during aging but also promotes maintenance of glucose tolerance, decreases dyslipidemia, and prevents liver lipid accumulation and steatosis.

Chronic exposure to a pollutant mixture at low doses led to tissue-specific metabolic alterations in male mice fed standard and high-fat high-sucrose diet

Excessive consumption of industrialized food and beverages is a major etiologic factor in the epidemics of obesity and associated metabolic diseases because these products are rich in fat and sugar. In addition, they contain food contact materials and environmental pollutants identified as metabolism disrupting chemicals. To evaluate the metabolic impact of these dietary threats (individually or combined), we used a male mouse model of chronic exposure to a mixture of low-dose archetypal food-contaminating chemicals that was added in standard or high-fat, high-sucrose (HFHS) diet. Specifically, the mixture contained bisphenol A, diethylhexylphthalate, 2,3,7,8-tetrachlorodibenzo-p-dioxine and polychlorinated biphenyl 153. Exposure lasted from 5 to 20 weeks of age. Metabolic exploration was conducted setting the basis of candidate gene expression mRNA analyses in liver, jejunum and adipose tissue depots from 20 week-old mice. Strong metabolic deleterious effects of the HFHS diet were demonstrated in line with obesity-associated metabolic features and insulin resistance. Pollutant exposure resulted in significant changes on plasma triglyceride levels and on the expression levels of genes mainly encoding xenobiotic processing in jejunum; estrogen receptors, regulators of lipoprotein lipase and inflammatory markers in jejunum and adipose tissues as well as adipogenesis markers. Importantly, the impact of pollutants was principally evidenced under standard diet. In addition, depending on nutritional conditions and on the metabolic tissue considered, the impact of pollutants could mimic or oppose the HFHS effects. Collectively, the present study extends the cocktail effect concept of a low-dosed pollutant mixture and originally points to tissue-specificity responsiveness especially in jejunum and adipose tissues.

Insulin-like growth factor-II in adipocyte regulation: depot-specific actions suggest a potential role limiting excess visceral adiposity.

The IGF system has an important role in growth and development. IGF-II is a recognized fetal growth promoter. However, its physiological postnatal role remains uncertain, although it is maintained in the circulation at a substantially high level throughout life. IGF-II has been strongly linked to obesity in genetic studies, and more recent evidence suggests a metabolic role. We examined fat depot differences in IGF-II's action on differentiation and metabolism. We speculate a specific effect on visceral adipocytes in relation to the differential distribution of insulin receptors between visceral and subcutaneous fat depots. We used a previously established adipocyte, cell culture system of matched pairs of visceral and subcutaneous fat biopsies from 20 normal weight children undergoing routine surgery for nonmalignant, nonseptic conditions. Preadipocytes were differentiated for 14 days in the presence or absence of IGF-II. Oil Red O staining, Western blotting, and reverse transcription polymerase chain reaction techniques were employed to assess levels of adipogenesis markers and levels of the insulin receptor and insulin receptor isoforms. Our data indicate that IGF-II promotes preadipocyte differentiation in subcutaneous preadipocytes but showed a protective, opposing effect restricting visceral preadipocyte differentiation, confirmed by reductions in the differentiation markers peroxisome proliferator-activated receptor gamma and adiponectin and in triglyceride staining. Additionally, IGF-II reduced mRNA expression of the insulin receptor in adipocytes and downregulated insulin receptor isoform A and glucose transporter 4 abundance and corresponding glucose uptake in visceral adipocytes. In conclusion, IGF-II is a regulator of preadipocyte differentiation and metabolism by acting as a differential modulator of fat accumulation favoring less visceral fat deposition in children.

Cartilage/bone interface fabricated under perfusion: Spatially organized commitment of adipose-derived stem cells without medium supplementation.

Tissue engineering of an osteochondral interface demands for a gradual transition of chondrocyte- to osteoblast-prevailing tissue. If stem cells are used as a single cell source, an appropriate cue to trigger the desired differentiation is the use of composite materials with different amounts of calcium phosphate. Electrospun meshes of poly-lactic-co-glycolic acid and amorphous calcium phosphate nanoparticles (PLGA/aCaP) in weight ratios of 100:0; 90:10, 80:20, and 70:30 were seeded with human adipose-derived stem cells (ASCs) and cultured in DMEM without chemical supplementation. After 2 weeks of static cultivation, they were either further cultivated statically for another 2 weeks (group 1), or placed in a Bose® bioreactor with a flow rate per area of 0.16 mL cm-2 min-1 (group 2). Markers for stem cell criteria, chondrogenesis, osteogenesis, adipogenesis and angiogenesis were analyzed by quantitative real-time PCR. Cell distribution, Sox9 protein expression and proteoglycans were assessed by histology. In group 2 (perfusion culture), chondrogenic Sox9 was upregulated toward the cartilage-mimicking side compared to pure PLGA. On the bone-mimicking side, Sox9 experienced a downregulation, which was confirmed on the protein level. Vice versa, expression of osteocalcin was upregulated on the bone-mimicking side, while it was unchanged on the cartilage-mimicking side. In group 1 (static culture), CD31 was upregulated in the presence of aCaP compared to pure PLGA, whereas Sox9 and osteocalcin expression were not affected. aCaP nanoparticles incorporated in electrospun PLGA drive the differentiation behavior of human ASCs in a dose-dependent manner. Discrete gradients of aCaP may act as promising osteochondral interfaces. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1833-1843, 2019.

Xylooligosaccharide supplementation decreases visceral fat accumulation and modulates cecum microbiome in mice

Xylooligosaccharide (XOS), an oligosaccharide with great prebiotic potential, has been shown to modulate the gut microbiota. Our aim was to determine the effects of dietary XOS supplementation on body composition, lipid metabolism and intestinal microbiota using a mouse model. Our data showed that XOS dietary supplementation at 2.1 and 7.0% significantly changed the gut microbial composition. A decrease in visceral fat depots, concentration of inflammatory cytokine MCP-1, and abundance of the two most important obesity associated gut microbial phyla Firmicutes and Bacteroidetes were observed with 7% XOS supplementation. No change in blood or liver lipids was observed with both XOS doses. The production of SCFAs in the cecum was increased and relative abundance of Actinobacteria was decreased with supplementation of both doses of XOS. To conclude, XOS supplementation reduced adiposity through decreasing gene expression of markers of adipogenesis and fat synthesis and induced changes in intestinal microbial composition.

Comparison of pro-adipogenic effects between prostaglandin (PG) D2 and its stable, isosteric analogue, 11-deoxy-11-methylene-PGD2, during the maturation phase of cultured adipocytes

Prostaglandin (PG) D2 is relatively unstable and dehydrated non-enzymatically into PGJ2 derivatives, which are known to serve as pro-adipogenic factors by activating peroxisome proliferator-activated receptor (PPAR) γ, a master regulator of adipogenesis. 11-Deoxy-11-methylene-PGD2 (11d-11m-PGD2) is a novel, chemically stable, isosteric analogue of PGD2 in which the 11-keto group is replaced by an exocyclic methylene. Here we attempted to investigate pro-adipogenic effects of PGD2 and 11d-11m-PGD2 and to compare the difference in their ways during the maturation phase of cultured adipocytes. The dose-dependent study showed that 11d-11m-PGD2 was significantly more potent than natural PGD2 to stimulate the storage of fats suppressed in the presence of indomethacin, a cyclooxygenase inhibitor. These pro-adipogenic effects were caused by the up-regulation of adipogenesis as evident with higher gene expression levels of adipogenesis markers. Analysis of transcript levels revealed the enhanced gene expression of two subtypes of cell-surface membrane receptors for PGD2, namely the prostanoid DP1 and DP2 (chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2)) receptors together with lipocalin-type PGD synthase during the maturation phase. Specific agonists for DP1, CRTH2, and PPARγ were appreciably effective to rescue adipogenesis attenuated by indomethacin. The action of PGD2 was attenuated by specific antagonists for DP1 and PPARγ. By contrast, the effect of 11d-11m-PGD2 was more potently interfered by a selective antagonist for CRTH2 than that for DP1 while PPARγ antagonist GW9662 had almost no inhibitory effects. These results suggest that PGD2 exerts its pro-adipogenic effect principally through the mediation of DP1 and PPARγ, whereas the stimulatory effect of 11d-11m-PGD2 on adipogenesis occurs preferentially by the interaction with CRTH2.

Impaired Adipogenesis and Dysfunctional Adipose Tissue in Human Hypertrophic Obesity.

The subcutaneous adipose tissue (SAT) is the largest and best storage site for excess lipids. However, it has a limited ability to expand by recruiting and/or differentiating available precursor cells. When inadequate, this leads to a hypertrophic expansion of the cells with increased inflammation, insulin resistance, and a dysfunctional prolipolytic tissue. Epi-/genetic factors regulate SAT adipogenesis and genetic predisposition for type 2 diabetes is associated with markers of an impaired SAT adipogenesis and development of hypertrophic obesity also in nonobese individuals. We here review mechanisms for the adipose precursor cells to enter adipogenesis, emphasizing the role of bone morphogenetic protein-4 (BMP-4) and its endogenous antagonist gremlin-1, which is increased in hypertrophic SAT in humans. Gremlin-1 is a secreted and a likely important mechanism for the impaired SAT adipogenesis in hypertrophic obesity. Transiently increasing BMP-4 enhances adipogenic commitment of the precursor cells while maintained BMP-4 signaling during differentiation induces a beige/brown oxidative phenotype in both human and murine adipose cells. Adipose tissue growth and development also requires increased angiogenesis, and BMP-4, as a proangiogenic molecule, may also be an important feedback regulator of this. Hypertrophic obesity is also associated with increased lipolysis. Reduced lipid storage and increased release of FFA by hypertrophic SAT are important mechanisms for the accumulation of ectopic fat in the liver and other places promoting insulin resistance. Taken together, the limited expansion and storage capacity of SAT is a major driver of the obesity-associated metabolic complications.

Regulation of adipogenesis by ceramide 1-phosphate

We showed previously that ceramide kinase (CerK) expression increases during adipogenesis pointing to a relevant role of intracellular C1P in this process. In the present work we demonstrate that administration of exogenous C1P inhibits the differentiation of 3T3-L1 pre-adipocytes into mature adipocytes through a mechanism involving activation of extracellularly regulated kinases (ERK) 1–2. Exogenous C1P reduced the accumulation of lipid droplets and the content of triacylglycerol in these cells, and potently inhibited the expression of the early and late adipogenic markers C/EBPβ and PPARγ, respectively. C1P also reduced the secretion of leptin, which is a crucial regulator of energy balance and appetite in the organism, and is considered to be a late marker of adipogenesis. Interestingly, all of these C1P actions were reversed by pertussis toxin, suggesting the intervention of a Gi protein-coupled receptor previously identified for C1P, in this process. Also, exogenous C1P significantly reduced CerK activity. Altogether, the data presented in this work suggest that exogenous C1P may balance adipogenesis, and that targeting CerK may be a novel way for potential applications in the treatment of obesity or other inflammation-associated diseases.

Grape Seed Proanthocyanidins Improve White Adipose Tissue Expansion during Diet-Induced Obesity Development in Rats.

The development of metabolic complications associated with obesity has been correlated with a failure of white adipose tissue (WAT) to expand. Our group has previously reported that a 12-week administration of grape seed proanthocyanidin extract (GSPE) together with an obesogenic diet mitigated the development of cardiometabolic complications in rats. Using the same cohort of animals, we aim to elucidate whether the prevention of cardiometabolic complications by proanthocyanidins is produced by a healthier expansion of visceral WAT and/or an induction of the browning of WAT. For this, adipocyte size and number in retroperitoneal WAT (rWAT) were determined by histological analyses, and the gene expression levels of markers of adipogenesis, browning, and WAT functionality were quantified by RT-qPCR. The long-term administration of GSPE together with an obesogenic diet expanded rWAT via an increase in the adipocyte number and a preventive decrease in the adipocyte size in a dose-dependent manner. At the molecular level, GSPE seems to induce WAT adipogenesis through the upregulation of peroxisome proliferator-activated receptor (Pparγ) in a Sirtuin 1 (Sirt1)-dependent manner. In conclusion, the healthier visceral WAT expansion induced by proanthocyanidins supplementation may explain the improvement in the cardiometabolic risks associated with obesogenic diets.

INT-767 prevents NASH and promotes visceral fat brown adipogenesis and mitochondrial function.

The bile acid receptors, farnesoid X receptor (FXR) and Takeda G-protein-coupled receptor 5 (TGR5), regulate multiple pathways, including glucose and lipid metabolism. In a rabbit model of high-fat diet (HFD)-induced metabolic syndrome, long-term treatment with the dual FXR/TGR5 agonist INT-767 reduces visceral adipose tissue accumulation, hypercholesterolemia and nonalcoholic steatohepatitis. INT-767 significantly improves the hallmarks of insulin resistance in visceral adipose tissue (VAT) and induces mitochondrial and brown fat-specific markers. VAT preadipocytes isolated from INT-767-treated rabbits, compared to preadipocytes from HFD, show increased mRNA expression of brown adipogenesis markers. In addition, INT-767 induces improved mitochondrial ultrastructure and dynamic, reduced superoxide production and improved insulin signaling and lipid handling in preadipocytes. Both in vivo and in vitro treatments with INT-767 counteract, in preadipocytes, the HFD-induced alterations by upregulating genes related to mitochondrial biogenesis and function. In preadipocytes, INT-767 behaves mainly as a TGR5 agonist, directly activating dose dependently the cAMP/PKA pathway. However, in vitro experiments also suggest that FXR activation by INT-767 contributes to the insulin signaling improvement. INT-767 treatment counteracts HFD-induced liver histological alterations and normalizes the increased pro-inflammatory genes. INT-767 also induces a significant reduction of fatty acid synthesis and fibrosis markers, while increasing lipid handling, insulin signaling and mitochondrial markers. In conclusion, INT-767 significantly counteracts HFD-induced liver and fat alterations, restoring insulin sensitivity and prompting preadipocytes differentiation toward a metabolically healthy phenotype.

Intracellular Calcium Determines the Adipogenic Differentiation Potential of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells via the Wnt5a/β-Catenin Signaling Pathway.

Mesenchymal stem cells- (MSCs-) based therapies show different degrees of efficacies for the treatment of various diseases, including lipogenesis. We evaluated the adipogenic differentiation ability of human umbilical cord blood-derived MSCs (hUCB-MSCs) from different donors and examined the contribution of the intracellular calcium (Ca2+) level to this diversity. hUCB-MSCs treated with Ca2+ or the Ca2+ chelator BAPTA-AM increased and decreased adipogenic differentiation, respectively. Canonical Wnt5a/β-catenin expression decreased during adipogenic differentiation of hUCB-MSCs. Treatment with Wnt5a blocked the adipogenic differentiation of hUCB-MSCs and activated the Wnt pathway, with a decrease in the adipogenesis markers PPARγ and leptin, and reduced lipid vacuole-associated Oil red O activity. In contrast, inhibition of the Wnt pathway with dickkopf-1 and β-catenin small interfering RNA transfection promoted the adipogenic potential of hUCB-MSCs. Interestingly, the Ca2+-based system exhibited a synergic effect on adipogenic potential through the Wnt5a/β-catenin pathway. Our data suggest that the variable adipogenic differentiation potential of hUCB-MSCs from different lots is due to variation in the intracellular Ca2+ level, which can be used as a marker to predict hUCB-MSCs selection for lipogenesis therapy. Overall, these results demonstrate that exogenous calcium treatment enhanced the adipogenic differentiation of hUCB-MSCs via negatively regulating the Wnt5a/β-catenin signaling pathway.

Abstract 1123: TRAF2 and NCK-interacting protein kinase (TNIK) regulates cancer stemness and adipogenesis of osteosarcoma cells

Abstract [Introduction] Osteosarcoma (OS) is a rare malignant bone tumor and affects predominantly adolescents and young adults. There is no molecular targeted therapy for OS and breakthrough intervention has long been awaited for decades. Disturbances in differentiation towards mature osteoblast from mesenchymal stem cell are related to OS pathogenesis. Wnt signaling is a key component in managing this differentiation process. We previously reported that TNIK was a positive regulator of Wnt signaling. To develop the first molecular targeted therapy for OS patients, we focused on Wnt pathway-targeted therapy in OS and initiated this study to demonstrate TNIK as a novel therapeutic target for OS treatment. [Methods] Eleven different osteosarcoma cell lines were used in the present study. Twenty clinical samples were obtained at biopsy and surgical resection from ten OS patients. TNIK expression was assessed by western blotting, immunofluorescence and immunohistochemical staining. The generation of the novel TNIK inhibitor was previously described (Masuda et al., 2016). Cells were cultured with TNIK inhibitor or siTNIK. Cell viability was evaluated by real-time cell analysis system or ATP quantitation assay. The effect of TNIK inhibitor in vivo was also assessed by a mouse xenograft model. RNA-seq was performed using the RNA extracted from vehicle or TNIK inhibitor-treated OS cells. Cancer stem cell (CSC)-like properties were assessed by soft-agar colony-formation assay, limiting dilution assay, ALDH activities and the expression of CSC markers. Adipogenic phenotypes were qualitatively and quantitatively analyzed by Oil red O staining and the expression of adipogenesis markers. [Results] TNIK was identified in all cell lines and most of cases. Immunohistochemistry of OS tissue microarray also revealed that 52 out of 55 OS samples were positive for TNIK protein. TNIK inhibitor suppressed OS cell proliferation both in vitro and in vivo. SiTNIK also inhibited OS cell growth. Global gene expression analysis revealed a significant decrease in the expression of the genes relating to Wnt signaling pathway and maintenance of stem cell pluripotency. Soft-agar colony-formation assay and limiting dilution assay revealed that TNIK inhibitor decreased sphere formation activities in OS cells. Accordingly, TNIK inhibitor significantly suppressed ALDH activities and the expression of the proteins that are involved in the maintenance of CSCs, including NANOG, SOX2, OCT4A and MYC. Concomitantly, TNIK inhibitor drove adipogenic transdifferentiation of OS cells with PPARG activation. TNIK knock-down U2OS cells created by shRNAs showed nearly identical results. [Conclusion] We present that TNIK inhibition promotes adipogenic transdifferentiation of OS cells and eliminates CSCs. Our study thus suggests the feasibility of TNIK as a target for OS treatment. Citation Format: Toru Hirozane, Mari Masuda, Naoko Goto, Teppei Sugano, Naofumi Asano, Eisuke Kobayashi, Keisuke Horiuchi, Hideo Morioka, Akira Kawai, Masaaki Sawa, Morio Matsumoto, Masaya Nakamura, Tesshi Yamada. TRAF2 and NCK-interacting protein kinase (TNIK) regulates cancer stemness and adipogenesis of osteosarcoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1123.

STAT1 Ablation in CD11c+ Cells Protects Mice from Obesity-Induced Insulin Resistance

Background: Obesity is a global epidemic and major risk factor for insulin resistance and type 2 diabetes. Obesity is associated with low grade chronic inflammation of adipose tissue (AT). F4/80+CD11c+ macrophages/dendritic cells are increased and polarized into M1-like phenotypes in AT and may contribute to insulin resistance in mouse models of obesity. STAT1 is a transcription factor that play key roles in macrophage polarization into M1-like phenotypes. Hence, we investigated the role of CD11c+ macrophage/dendritic cell STAT1 in obesity-induced AT inflammation and insulin resistance. Methods: Mice with specific knockout of STAT1 in CD11c+ cells were generated by crossbreeding STAT1 fl/fl and CD11c-Cre mice. CD11c/STAT1 KO and littermate controls were fed either high fat diet (HFD, for 16 weeks) to induce obesity or normal diet (ND) as lean controls. We evaluated body composition, insulin sensitivity, gene expression of inflammatory markers, various immune cells and brown/beige adipogenesis markers in AT. Results: Perigonadal white AT (PWAT) and body weight were not significantly different between KO and control groups but liver weight and liver-to-body weight ratio were significantly reduced in obese KO mice (p<0.05). STAT1 KO mice on HFD exhibited improved insulin sensitivity examined by insulin tolerance test (p<0.05) and reduced expression of inflammatory markers TNFα, IFNγ, IL-12 and MCP1 in PWAT and subcutaneous AT (SAT) compared to littermate controls (p<0.05). AT immune cell analysis revealed that STAT1 ablation caused a decrease in M1-like proinflammatory polarization and increase in M2-like polarization of F4/80+ macrophages, reduced number of total CD3+ T cells and CD8+T cells in PWAT. In addition, brown/beige adipogenesis markers UCP1, CIDEA and Prdm16 also upregulated (p<0.05) in SAT of obese KO mice. Conclusion: Our results show the critical role of macrophage/dendritic cell STAT1 in obesity-induced AT inflammation and insulin resistance. Disclosure A. Kalathookunnel Antony: None. X.D. Perrard: None. Z. Lian: None. J. Perrard: None. L. Hennighausen: None. C.W. Smith: None. C.M. Ballantyne: Research Support; Self; Abbott, Amarin Corporation, Amgen Inc., Esperion Therapeutics, Ionis Pharmaceuticals, Inc., Novartis Pharmaceuticals Corporation, Pfizer Inc., Regeneron Pharmaceuticals, Inc., Roche Diagnostics Corporation, Sanofi. Consultant; Self; Abbott, Amarin Corporation, Amgen Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Esperion Therapeutics, Ionis Pharmaceuticals, Inc., Matinas BioPharma, Merck & Co., Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Pfizer Inc., Regeneron Pharmaceuticals, Inc., Roche Diagnostics Corporation, Sanofi. H. Wu: None.

3D printing bioactive PLGA scaffolds using DMSO as a removable solvent

Present bioprinting techniques lack the methodology to print with bioactive materials that retain their biological functionalities. This constraint is due to the fact that extrusion-based printing of synthetic polymers is commonly performed at very high temperatures in order to achieve desired mechanical properties and printing resolutions. Consequently, current methodology prevents printing scaffolds embedded with bioactive molecules, such as growth factors. With the wide use of mesenchymal stem cells (MSCs) in regenerative medicine research, the integration of growth factors into 3D printed scaffolds is critical because it can allow for inducible MSC differentiation. We have successfully incorporated growth factors into extrusion printed poly (lactic-co-glycolic acid) (PLGA) scaffolds by introducing dimethyl sulfoxide (DMSO) for low temperature printing. Mechanical testing results demonstrated significantly different compressive and tensile properties for PLGA scaffolds printed with or without DMSO. In particular, the PLGA/DMSO scaffolds displayed a highly stretchable feature compared to the regular PLGA scaffolds. The cellular response of growth factor introduction was evaluated in vitro using human mesenchymal stem cells (hMSCs). By evaporating the DMSO after printing, we ensured that there was no cytotoxic effect on seeded hMSCs. The addition of lineage specific growth factors led to increased expression of corresponding genetic markers for chondrogenesis, osteogenesis, and adipogenesis. We concluded that the use of DMSO for 3D printed scaffold fabrication with bioactive items is a revolutionary methodology in advancing regenerative medicine. The incorporation of bioactive molecules opens pathways to more therapeutic uses for 3D printing in treating damaged or deteriorating native tissue.

Interleukin-4 Restores Insulin Sensitivity in Lipid-Induced Insulin-Resistant Adipocytes.

Obesity and latent inflammation in adipose tissue significantly contribute to the development of insulin resistance (IR) and type 2 diabetes. Here we studied whether the antiinflammatory interleukin-4 (IL-4) can restore insulin sensitivity in cultured 3T3-L1 adipocytes. The activity of key components of the insulin signaling cascade was assessed by immunoblotting using phospho-specific antibodies to insulin receptor substrate IRS1 (Tyr612), Akt (Thr308 and Ser473), and AS160 (Ser318) protein that regulates translocation of the GLUT4 glucose transporter to the plasma membrane. IR was induced in mature adipocytes with albumin-conjugated palmitate. IR significantly reduced phosphorylation levels of all the above-mentioned proteins. Addition of IL-4 to the culturing medium during IR induction led to a dose-dependent stimulation of the insulin-promoted phosphorylation of IRS1, Akt, and AS160. At the optimal concentration of 50ng/ml, IL-4 fully restored activation of the insulin cascade in IR cells, but it did not affect insulin signaling activation in the control cells. IL-4 neither upregulated expression of key adipogenesis markers GLUT4 and PPARγ nor caused lipid accumulation in the adipocytes. These results demonstrate that IL-4 can restore insulin sensitivity in adipocytes via mechanisms not associated with induced adipogenesis or de novo formation of lipid depots.

DEHP deregulates adipokine levels and impairs fatty acid storage in human SGBS-adipocytes

DEHP is a plasticizer which has been used in plastic products of everyday use for decades. Studies in mice and murine cell culture models identified DEHP as an endocrine disruptor that may also act as an obesogen. As this is of high concern in respect of the worldwide obesity epidemic, our aim is the translation of these findings into a human model system. On the basis of DOHaD, we investigated the influence of an environmentally relevant dose of DEHP [50 µg/ml] on adipogenesis in the human cell culture model SGBS. Pre-adipocytes were exposed to DEHP and differentiated into mature adipocytes. At different stages of differentiation, markers of adipogenesis like GLUT4, FABP4, LPL and PPARs, and of signaling pathways like AMPK/ACC2, JAK/STAT and MAPK were analyzed. Functional markers like adipokine secretion and triglyceride content as well as ROS production were measured in mature adipocytes. We found significantly lower expression levels of adipogenic markers, a reduction in lipid accumulation, higher leptin- and reduced adiponectin levels in the supernatant of treated adipocytes. Moreover, ROS production was significantly elevated after DEHP-exposure. In conclusion, DEHP led to lower grade of adipogenic differentiation in human SGBS-adipocytes under the chosen conditions.