Search

Blood-based biomarker assays of plasma β-amyloid (Aβ) and tau have the advantages of cost-effective and less invasive for the diagnosis of Alzheimer's disease (AD). We used two independent cohorts to cross-validate the clinical use of the nanoparticle-based immunomagnetic assay of plasma biomarkers to assist in the differential diagnosis of early AD. There were in total 160 subjects in the derivation cohort, and 242 in the validation cohort both containing controls, mild cognitive impairment due to AD and AD dementia diagnosed according to the 2011 NIA-AA guidelines. The cutoff value for plasma Aβ1–42 (16.4 pg/ml) performed the best in differentiating between controls and patients with prodromal or clinical AD, with 92.5% for positive percent agreement (PPA), negative percent agreement (NPA), and overall rate of agreement (ORA). Aβ1–42 × tau (642.58) was useful for separating patients with dementia and prodromal states of AD, with 84.9% PPA, 78.8% NPA and 83% ORA.

The feasibility of assaying plasma phosphorylated tau protein (threonine 181), denoted p-tau181, using immunomagnetic reduction (IMR) is explored. The reagent for assaying p-tau181 with IMR was synthesized, and its analytic performances were characterized. Seventy-three subjects were recruited. Each participant was examined with neuropsychological tests, magnetic resonance imaging, and IMR assay for plasma p-tau181. Using commercially available IMR kits, the plasma total tau protein (T-tau) of each subject was assayed. The dynamic range for assaying p-tau181 using IMR was 1.96×10-2 pg/ml to 104 pg/ml. There was no significant interference from total tau protein in the assay of p-tau181. The measured concentrations of plasma p-tau181 were 2.46±1.09 pg/ml for healthy controls, 4.41±1.85 pg/ml for MCI due to AD, and 6.14±1.59 pg/ml for very mild AD. Meanwhile, the measured concentrations of plasma T-tau were 18.85±10.16 pg/ml for healthy controls, 32.98±10.18 pg/ml for MCI due to AD, and 37.54±12.29 pg/ml for very mild AD. A significant difference in plasma p-tau181 was observed between healthy controls and MCI due to AD (p < 0.001) and between MCI due to AD and very mild AD (p < 0.001). However, for the plasma T-tau concentration, a significant difference existed only between healthy controls and MCI due to AD (p < 0.001). This implies that the plasma p-tau181 level is correlated more to AD severity than plasma T-tau is. Additionally, p-tau181 was observed as approximately 14% of T-tau in human plasma.

Figure S2. Mouse ADN recombinant protein induced the phosphorylation of AMPK in porcine adipocyte. (A) Porcine adipocyte was treated with mouse ADN recombination protein (10 μg/mL); the levels of AMPK, phospho-AMPK, and actin at 0, 5 and 15 min after treatment were detected by western blot. (B) Densitometric analysis of phospho-AMPK and AMPK levels was conducted using image J software. Mouse ADN increased the ratio of phosphor-AMPK and AMPK at 15 min in porcine adipocyte. Data were analyzed by one way ANOVA with mean separation using Tukey’s test. Means with different letters indicated p ≤ 0.05. (PDF 229 kb)

Figure S1. Sequence alignment of human, pig and mouse AdipoR1. The sequence of Homo sapiens, Sus scrofa, and Mus musculus AdipoR1 were aligned using the software BioEdit. The sequences and their GenBank accession numbers are: Homo sapiens (NP_057083.2), Sus scrofa (NP_001007194) and Mus musculus (NP_082596.2). Boxes show the zinc-binding site (residues 187–212, 333–347) and C-terminal extracellular region/CTR (residues 365–375) of AdipoR1 which are conserved between pig and mouse. (PDF 216 kb)

Figure S3. Mouse ADN bound to porcine AdipoR1 in pAdipoR1 mice. (A) Mouse ADN (mADN) bound with mouse AdipoR1 in wild type (WT) mice, and mADN bound with mouse and flag-conjugated porcine AdipoR1 in pAdipoR1 mice. (B) Co-immunoprecipitation (co-IP) between m-ADN and flag-pAdipoR1. To confirm the mADN binds with pAdipoR1, IP was performed using anti-ADN antibody followed by immunoblotting using anti-flag antibody and anti-ADN antibody in the colon of WT and AdipoR1 mice. Flag-pAdpoR1 was detectable in the protein of AdipoR1 mice. ADN was detectable both in the WT and AdipoR1 mice. mADN: mouse adiponectin; mAdipoR1: mouse adiponectin receptor 1; f-pAdipoR1: porcine adiponectin receptor 1 conjugated with flag; IB: immunoblotting. (PDF 187Â kb)

Table S1. Primer sets for quantitative real-time PCR. Primers were designed using the Primer-BLAST tool of National Center for Biotechnology Information (NCBI). Each primer sequence was confirmed by aligning its reference sequence in the NCBI database. (PDF 202Â kb)

Background Adiponectin (ADN) is an adipokine derived from adipocytes. It binds to adiponectin receptor 1 and 2 (AdipoR1 and R2) to exert its function in regulating whole-body energy homeostasis and inflammatory responses. However, the role of ADN-AdipoR1 signaling in intestinal inflammation is controversial, and its role in the regulation of neutrophils is still unclear. Our goal was to clarify the role of AdipoR1 signaling in colitis and the effects on neutrophils. Methods We generated porcine AdipoR1 transgenic mice (pAdipoR1 mice) and induced murine colitis using dextran sulfate sodium (DSS) to study the potential role of AdipoR1 in inflammatory bowel disease. We also treated a THP-1 macrophage and a HT-29 colon epithelial cell line with ADN recombinant protein to study the effects of ADN on inflammation. Results After inducing murine colitis, pAdipoR1 mice developed more severe symptoms than wild-type (WT) mice. Treatment with ADN increased the expression of pro-inflammatory factors in THP-1 and HT-29 cells. Moreover, we also observed that the expression of cyclooxygenase2 (cox2), neutrophil chemokines (CXCL1, CXCL2 and CXCL5), and the infiltration of neutrophils were increased in the colon of pAdipoR1 mice. Conclusions Our study showed that ADN-AdipoR1 signaling exacerbated colonic inflammation through two possible mechanisms. First, ADN-AdipoR1 signaling increased pro-inflammatory factors. Second, AdipoR1 enhanced neutrophil chemokine expression and recruited neutrophils into the colonic tissue to increase inflammation. Electronic supplementary material The online version of this article (10.1186/s12929-018-0419-3) contains supplementary material, which is available to authorized users.

Immunomagnetic reduction (IMR), which involves the use of antibody-functionalized magnetic nanoparticles to specifically label target biomarkers, was utilized to develop an assay for total tau protein in human plasma. The analytic properties of the IMR assay on tau protein were investigated. The limit of detection was found to be 0.026 pg/ml. Other properties such as Hook effect, assay linearity, dilution recovery range, reagent stability, interference test, and spiked recovery were also characterized. The ultra-sensitive IMR assay was applied to detect the plasma tau protein levels of subjects with prevalent neurodegenerative diseases, such as Alzheimer’s disease (AD), mild cognitive impairment (MCI) due to AD, Parkinson’s disease (PD), frontotemporal dementia (FTD) and vascular dementia (VD). The concentrations of plasma tau protein in patients with VD, PD, MCI due to AD, FTD, and AD patients were higher than that of healthy controls. Using an ROC curve analysis, the cutoff value for discriminating dementia patients from healthy controls was 17.43 pg/ml, resulting in 0.856 and 0.727 for clinical sensitivity and specificity, respectively. The area under the ROC curve was 0.908. These results imply that the IMR plasma tau assay would be useful to screen for prevalent neurodegenerative diseases.

The unique advantage of easy access and abundance make the adipose-derived stem cells (ADSCs) a promising system of multipotent cells for transplantation and regenerative medicine. Among the available sources, porcine ADSCs (pADSCs) deserve especial attention due to the close resemblance of human and porcine physiology, as well as for the upcoming availability of humanized porcine models. Here, we report on the isolation and conversion of pADSCs into glucose-responsive insulin-secreting cells. We used the stromal-vascular fraction of the dorsal subcutaneous adipose from 9-day-old male piglets to isolate pADSCs, and subjected the cells to an induction scheme for differentiation on chitosan-coated plates. This one-step procedure promoted differentiation of pADSCs into pancreatic islet-like clusters (PILC) that are characterized by the expression of a repertoire of pancreatic proteins, including pancreatic and duodenal homeobox (Pdx-1), insulin gene enhancer protein (ISL-1) and insulin. Upon glucose challenge, these PILC secreted high amounts of insulin in a dose-dependent manner. Our data also suggest that chitosan plays roles not only to enhance the differentiation potential of pADSCs, but also to increase the glucose responsiveness of PILCs. Our novel approach is, therefore, of great potential for transplantation-based amelioration of type 1 diabetes.

Mesenchymal stem cells may differentiate into cardiomyocytes and participate in local tissue repair after heart injury. In the current study, rat adipose-derived adult stem cells (ASCs) grown on chitosan membranes were observed to form cell spheroids after 3 days. The cell seeding density and surface modification of chitosan with Arg-Gly-Asp–containing peptide had an influence on the sizes of ASC spheroids. In the absence of induction, these spheroids showed an increased level of cardiac marker gene expression (Gata4, Nkx2-5, Myh6, and Tnnt2) more than 20-fold versus cells on the tissue culture polystyrene (TCPS) dish. Induction by 5-azacytidine or p38 MAP kinase inhibitor (SB202190) did not further increase the cardiac marker gene expression of these spheroids. Moreover, the enhanced cardiomyogenic potential of the spheroids was highly associated with the chitosan substrates. When ASC spheroids were plated onto TCPS with either basal or cardiac induction medium for 9 days, the spheroids spread into a monolayer and the positive effect on cardiomyogenic marker gene expression disappeared. The possible role of calcium ion and the up-regulation of adhesion molecule P-selectin and chemokine receptor Cxcr4 were demonstrated in ASC spheroids. Applying these spheroids to the chronic myocardial infarction animal model showed better functional recovery versus single cells after 12 weeks. Taken together, this study suggested that the ASC spheroids on chitosan may form as a result of calcium ion signaling, and the transplantation of these spheroids may offer a simple method to enhance the efficiency of stem cell–based therapy in myocardial infarction.

Adiponectin and its receptors have been demonstrated to play important roles in regulating glucose and lipid metabolism in mice. Obesity, type II diabetes and cardiovascular disease are highly correlated with down-regulated adiponectin signaling. In this study, we generated mice overexpressing the porcine Adipor1 transgene (pAdipor1) to study its beneficial effects in metabolic syndromes as expressed in diet-induced obesity, hepatosteatosis and insulin resistance. Wild-type (WT) and pAdipor1 transgenic mice were fed ad libitum with a standard chow diet (Chow) or a high-fat/sucrose diet (HFSD) for 24 weeks, beginning at 6 to 7 weeks of age. There were 12 mice per genetic/diet/sex group. When challenged with HFSD to induce obesity, the pAdipor1 transgenic mice resisted development of weight gain, hepatosteatosis and insulin resistance. These mice had lowered plasma adiponectin, triglyceride and glycerol concentrations compared to WT mice. Moreover, we found that (indicated by mRNA levels) fatty acid oxidation was enhanced in skeletal muscle and adipose tissue, and liver lipogenesis was inhibited. The pAdipor1 transgene also restored HFSD-reduced phosphoenolpyruvate carboxykinase 1 (Pck1) and glucose transporter 4 mRNA in the adipose tissues, implying that the increased Pck1 may promote glyceroneogenesis to reduce glucose intolerance and thus activate the flux of glyceride-glycerol to resist diet-induced weight gain in the adipose tissues. Taken together, we demonstrated that pAdipor1 can prevent diet-induced weight gain and insulin resistance. Our findings may provide potential therapeutic strategies for treating metabolic syndromes and obesity, such as treatment with an ADIPOR1 agonist or activation of Adipor1 downstream targets.

α-Synuclein is critical to the pathogenesis of Parkinson's disease (PD). Few studies examined the plasma levels of α-synuclein due to the exceptionally low level of α-synuclein in plasma compared with cerebrospinal fluid. We aimed to investigate plasma α-synuclein in patients with PD of different disease severity.There were total 114 participants, including 80 patients with PD and 34 controls, in the study. Participants received a complete evaluation of motor and non-motor symptoms, including cognitive function. We applied immunomagnetic reduction-based immunoassay to measure plasma levels of α-synuclein.Plasma levels of α-synuclein were significantly higher in patients with PD compared with controls (median: 1.56 pg/mL, 95% CI 1.02 to 1.98 pg/mL vs 0.02 pg/mL, 95% CI 0.01 to 0.03 pg/mL; p0.0001). Although there was a significant increase in plasma α-synuclein levels in PD patients with a higher Hoehn-Yahr (H-Y) stage, there was no correlation with motor symptom severity, as assessed by Unified Parkinson's Disease Rating Scale part III scores, after confounders (age, gender, and disease duration) were taken into account. However, plasma α-synuclein levels were significantly higher in PD patients with dementia (PDD) than in PD patients with mild cognitive impairment (PD-MCI) or normal cognition (0.42 pg/mL, (95% CI 0.25 to 0.93) for PD with normal cognition; 1.29 pg/mL (95% CI 0.76 to 1.93) for PD-MCI and 4.09 pg/mL (95% CI 1.99 to 6.19) for PDD, p0.01) and were negatively correlated with Mini-Mental State Examination scores (ROur data suggest that plasma α-synuclein level correlates with cognitive decline but not motor severity in patients with PD. Plasma α-synuclein could serve as a surrogate biomarker for patients at risk of cognitive decline.

Visfatin is a visceral adipose tissue-specific adipocytokine that plays a positive role in attenuating insulin resistance by binding to the insulin receptor. Visfatin has been suggested to play a role in the regulation of lipid metabolism and inflammation; however, the mechanism remains unclear. We investigated the effects of visfatin on the regulation of gene expression in cultured porcine preadipocytes and differentiated adipocytes. In preadipocytes, the mRNA abundance of lipoprotein lipase and PPARgamma were significantly increased by visfatin or insulin treatment after 8 d (all P < 0.05). In the presence of insulin, the mRNA abundance of adipocyte fatty acid-binding protein was 24.7-fold greater than in the untreated group (P < 0.05), whereas visfatin alone had no effect on adipocyte fatty acid-binding protein mRNA abundance. Adipocyte differentiation was induced by insulin treatment for 8 d. In differentiated porcine adipocytes, exposure to insulin or visfatin for 24 h increased (P < 0.05) fatty acid synthase mRNA abundance but had no effect on the expression of sterol regulatory element binding-protein 1c mRNA. We also found a 5.8-fold upregulation of IL-6 expression in porcine adipocytes after 24 h of treatment with visfatin (P < 0.05). These results demonstrated that visfatin upregulated lipoprotein lipase expression in preadipocytes, potentially facilitating lipid uptake, and increased the gene expression of fatty acid synthase in differentiated adipocytes to potentially enhance lipogenic activity. Furthermore, visfatin can upregulate IL-6 expression in differentiated porcine adipocytes. The information presented in this study provides insights into the roles of visfatin in lipid metabolism in pigs.

Adiponectin is an adipocyte-derived hormone that can improve insulin sensitivity. Its functions in regulating glucose utilization and fatty acid metabolism in mammals are mediated by 2 subtypes of adiponectin receptors (AdipoR1 and AdipoR2). This study was conducted to determine the effect of fasting on the expression of adiponectin and its receptors. The expression of adiponectin was not affected in s.c. adipose tissue, but adiponectin expression increased in visceral adipose tissue after fasting. In contrast, expression of both AdipoR mRNA was increased in the liver and s.c. adipose tissue of 24-h-fasted pigs compared with fed pigs, but the mRNA in muscle and visceral adipose tissue was not affected by fasting. A third putative adiponectin receptor, T-cadherin, was cloned and the mRNA expression was determined. T-Cadherin has been recognized to act as a vascular adiponectin receptor in vascular endothelial and smooth muscle cells. Our data showed that the expression of T-cadherin was decreased in the muscle of fasted pigs, suggesting that the expression of T-cadherin can be regulated by feeding status. In summary, in young pigs, adiponectin mRNA was up-regulated by fasting in visceral, but not s.c., adipose tissue, whereas AdipoR1 and AdipoR2 mRNA were increased in s.c., but not visceral, adipose tissue. The adiponectin receptor, T-cadherin, was expressed in s.c. and visceral adipose tissue and in muscle, but only muscle mRNA expression was decreased by fasting.

Background It is difficult to discriminate healthy subjects and patients with Parkinson disease (PD) or Parkinson disease dementia (PDD) by assaying plasma α-synuclein because the concentrations of circulating α-synuclein in the blood are almost the same as the low-detection limit using current immunoassays, such as enzyme-linked immunosorbent assay. In this work, an ultra-sensitive immunoassay utilizing immunomagnetic reduction (IMR) is developed. The reagent for IMR consists of magnetic nanoparticles functionalized with antibodies against α-synuclein and dispersed in pH-7.2 phosphate-buffered saline. A high-Tc superconducting-quantum-interference-device (SQUID) alternative-current magnetosusceptometer is used to measure the IMR signal of the reagent due to the association between magnetic nanoparticles and α-synuclein molecules. Results According to the experimental α-synuclein concentration dependent IMR signal, the low-detection limit is 0.3 fg/ml and the dynamic range is 310 pg/ml. The preliminary results show the plasma α-synuclein for PD patients distributes from 6 to 30 fg/ml. For PDD patients, the concentration of plasma α-synuclein varies from 0.1 to 100 pg/ml. Whereas the concentration of plasma α-synuclein for healthy subjects is significantly lower than that of PD patients. Conclusions The ultra-sensitive IMR by utilizing antibody-functionalized magnetic nanoparticles and high-Tc SQUID magnetometer is promising as a method to assay plasma α-synuclein, which is a potential biomarker for discriminating patients with PD or PDD.

Shrimp white spot disease (WSD), which is caused by white spot syndrome virus (WSSV), is one of the world's most serious shrimp diseases. Our objective in this study was to use an immunomagnetic reduction (IMR) assay to develop a highly sensitive, automatic WSSV detection platform targeted against ICP11 (the most highly expressed WSSV protein). After characterizing the magnetic reagents (Fe3O4 magnetic nanoparticles coated with anti ICP11), the detection limit for ICP11 protein using IMR was approximately 2 x 10(-3) ng/ml, and the linear dynamic range of the assay was 0.1~1 x 10(6) ng/ml. In assays of ICP11 protein in pleopod protein lysates from healthy and WSSV-infected shrimp, IMR signals were successfully detected from shrimp with low WSSV genome copy numbers. We concluded that this IMR assay targeting ICP11 has potential for detecting the WSSV.

Peroxisome proliferator-activated receptor gamma2 (PPARgamma) is a nuclear transcription factor that regulates adipocyte differentiation and lipogenic genes during adipogenesis. The activity of rodent PPARgamma is regulated by phosphorylation of serine 112. The current experiment was designed to study the ability of porcine PPARgamma to stimulate transdifferentiation of myoblasts to adipocytes by overexpressing wild-type PPARgamma or mutated PPARgamma (serine 112 was mutated to alanine) in mouse myoblast cells. The expression of adipogenic marker genes (adipocyte fatty acid binding protein, lipoprotein lipase, and glycerol-3 phosphate dehydrogenase) in cells stably expressing mutated porcine PPARgamma was greater than in cells with wild-type PPARgamma, indicating that the mutated PPARgamma has greater adipogenic capability than the wild-type PPARgamma. Under treatment with a ligand, both wild-type and mutant porcine PPARgamma-expressing C2C12 myoblasts differentiated into adipocytes in 10 d. The expression of myogenic marker genes (myogenin, myogenic regulatory factor-4) was suppressed in cells transfected with the mutated PPARgamma or wild-type PPARgamma. Moreover, wild-type and mutant PPARgamma were able to inhibit myogenesis without addition of a ligand. Our results suggest that porcine wild-type PPARgamma and mutated PPARgamma can both convert myoblast cells into adipocytes, and also that the ability to transdifferentiate was greater in cells containing the mutated PPARgamma than in cells containing the wild-type PPARgamma. Therefore, the existence of serine 112 in PPARgamma may have a role in regulating adipocyte differentiation.

Adipocyte determination and differentiation-dependent factor 1 (ADD1) drives the expression of several lipogenic genes in mammals. Polyunsaturated fatty acids decrease ADD1 mRNA abundance in differentiating porcine adipocytes. The current study was designed to explore the mechanisms by which PUFA inhibit the expression of ADD1 in porcine adipocytes. Porcine preadipocytes were differentiated for 24 h with 0 or 100 microM of docosahexaenoic acid (DHA) and mixtures of different concentrations of antioxidants to investigate the effect of DHA and antioxidants on the ADD1 mRNA abundance. We found the relative mRNA abundance was decreased by the addition of 100 microM DHA to the medium for porcine differentiating adipocytes, and adding an antioxidant mixture to the medium prevented part of the decrease in ADD1 mRNA abundance. These data suggest that DHA decreased the steady-state transcription factor ADD1 mRNA through a mechanism related to fatty acid peroxidation. Indeed, adding 7.5 microM vitamin E (a natural antioxidant) also restored the concentrations of ADD1 and fatty acid synthase mRNA, which were decreased by DHA treatment; however, the DHA or the antioxidant treatment did not change the expression of antioxidation genes (superoxide dismutase 1 and glutathione peroxidase 1) in porcine stromal vascular cells. When supplemented with the eicosanoid synthesis pathway inhibitors, the inhibition of the expression of ADD1 by arachidonic acid was partially recovered. These results suggest that the mechanism by which PUFA decrease ADD1 mRNA is due to the metabolic product of eicosanoids and peroxidation of these PUFA.

Background Magnetic nanoparticles functionalized antibodies are used for in-vitro assays on bio-markers. This work demonstrates the synthesis of high-quality magnetic nanoparticles coated with antibodies against carcinoembryonic antigen (CEA). Various characterizations, such as particle size, particle suspension, bio-activity and the stability of bio-magnetic nanoparticles suspended in liquid, are studied. The properties for the assay of CEA molecules in serum are also studied. The assay method used is so-called immunomagnetic reduction. Results The results show that the effects of common materials in serum that interfere with detected signals are not significant. The low-detection limit is 0.21 ng/ml, which is well below the clinical threshold of 2.5 ng/ml. Conclusions The dynamic range for the assay of CEA molecules in serum is 500 ng/ml. By assaying serum CEA molecules from 24 normal controls and 30 colorectal-cancer patients, the threshold for the serum-CEA concentration to diagnose colorectal cancer is 4.05 ng/ml, which results in a clinical sensitivity of 0.90 and specificity of 0.87.

Studies show that adiponectin and its receptors (AdipoR1 and 2) play important roles in regulating glucose and lipid metabolism in mice. Obesity, type II diabetes and cardiovascular disease are highly correlated with downregulated adiponectin signaling; however, research has not clarified the functions of AdipoR1 in vivo.In this study, mice were induced to overexpress the AdipoR1 transgene so that its functions could be studied in relation to hypertrophic cardiomyopathy. Wild-type and AdipoR1-transgenic male mice were fed ad libitum with a standard chow diet or else a high-fat/sucrose diet (HFSD) for 24 weeks, beginning at 6-7 weeks of age.After receiving the 24-week HFSD, AdipoR1-transgenic mice did not become obese, nor did they develop heart hypertrophy. The AdipoR1 transgene decreased the elevating cardiac troponin I expression caused by the HFSD. While the HFSD induced mRNA expression of CD36 and CPTI, AdipoR1 reversed it. Suppression of cardiac SOD mRNA expression by the HFSD was improved by the AdipoR1 transgene. The HFSD caused a higher autophagic gene expression of Beclin 1 and Lamp 2 A in the heart, whereas the AdipoR1 transgene ameliorated them.The AdipoR1 transgene enabled mice to resist diet-induced obesity while decreasing lipid accumulation, oxidative stress and autophagic damage. These effects might contribute to the improvement of heart functions in diet-induced obese mice.

Background aims Obesity and its associated diseases demand better therapeutic strategies. Regenerative medicine combined with gene therapy has emerged as a promising approach in various clinical applications. Adiponectin (ApN) and its receptors have been demonstrated to play beneficial roles in modulating glucose and lipid homeostasis. In the current study, we tested such an approach by transplanting mesenchymal stromal cells (MSCs) from porcine ApN receptor (pAdipoR) 1-transgenic mice into high-fat/sucrose diet (HFSD)-fed mice. Methods Twenty 6-week-old Friend virus B/NJNarl male mice were randomly assigned into four groups with the control fed a chow diet (chow) and others HFSD for 10 months. The HFSD groups were then intraperitoneally injected once per week for 8 weeks with placebo (200 μL phosphate-buffered saline), wild-type MSC (WT-MSC, 2 × 10 6 cells/200 μL phosphate-buffered saline) or pAdipoR1-transgenic MSC (pR1-tMSC, 2 × 10 6 cells/200 μL phosphate-buffered saline), respectively. Body weights, blood samples, tissue histology, and gene expression and protein levels of metabolism-associated genes were analyzed. Results Both WT-MSC and pR1-tMSC transplantations restored the messenger RNA expression of AdipoR1, with those of glucose transporter 4 and 5′-adenosine monophosphate-activated protein kinase catalytic subunit α-1 and protein levels of pyruvate kinase induced by pR1-tMSC in the muscles of HFSD-fed mice. In the liver, both WT-MSC and pR1-tMSC ameliorated HFSD-induced hepatosteatosis, with the gene expression of lipoprotein lipase and hormone-sensitive lipase upregulated by the latter. Lastly, pR1-tMSC transplantation reduced fatty acid synthase mRNA levels in the adipose tissues of HFSD-fed mice. Conclusions This study demonstrates the modulatory actions of MSC and pR1-tMSC on genes associated with glucose and lipid metabolism and provides insights into its therapeutic application for obesity-associated metabolic complication.

Mesenchymal stem cells (MSCs) were recently found to form three-dimensional (3D) multicellular spheroids on chitosan membranes. The exact mechanism of spheroid formation, however, remains unclear. In this study, the regulation of spheroid formation for adipose derived adult stem cells (ADAS) grown on chitosan membranes was examined. By varying the membrane thickness, calcium concentration in culture medium, and acetylation extent of chitosan, the physico-chemical characteristics of chitosan that modulated spheroid formation was elucidated. The capacity of cardiomyogenic differentiation was further evaluated. Results suggested that the calcium binding capacity of chitosan may affect the cell-substrate and cell-cell interactions and critically influence the dynamics of spheroid formation. The intracellular calcium level was elevated for ADAS spheroids on chitosan. Chitosan-bound calcium was observed to enter the cells. The expression of N-cadherin was upregulated for ADAS spheroids on chitosan, evidenced by quantitative RT-PCR and Western blot. After the induction by 5-aza, the expression levels of cardiac marker genes (Gata4, Nkx2.5, Tnnt2, and Myh6) were remarkably enhanced (about four-fold) for ADAS on chitosan vs. tissue culture polystyrene or polyvinyl alcohol. Immunofluorescence staining confirmed the expression of cardiac-associated tight junction protein ZO-1 for ADAS grown on chitosan membranes. The gene expression of Wnt11 was significantly upregulated for ADAS spheroids on chitosan at 3 days and 12 days. We suggested that Wnt11 may be involved in the spheroid formation and cardiomyogenic differentiation of MSCs on chitosan membranes. Spheroids formed on the acetylated chitosan or polyvinyl alcohol membranes failed to show such behavior. The properties of MSC spheroids were therefore determined by the culture substrate.

Adiponectin is an adipocyte-derived hormone that can improve insulin sensitivity. Its functions in regulating glucose utilization and fatty acid metabolism in mammals are mediated by two subtypes of adiponectin receptors (AdipoR1 and AdipoR2). This study was conducted to determine the effect of insulin on the expression of adiponectin and its receptors. We demonstrated that in the presence of 10 nM insulin, addition of 1 microM of insulin or rosiglitazone (a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist) had no effect on the expression of adiponectin and AdipoR genes in differentiated porcine adipocytes. However, the addition of 1 microM insulin plus 1 microM rosiglitazone significantly increased the AdipoR2 mRNA in differentiated porcine adipocytes. Using the phosphatidylinositol 3-kinase inhibitor (PI3K inhibitor, LY 294002), we found that insulin inhibited the expression of AdipoR2 through the PI3K pathway and this inhibition was blocked by addition of rosiglitazone. When porcine adipocytes were cultured without insulin, supplementation with 10 nM insulin inhibited the expression of AdipoR2 and this inhibition effect was also blocked by addition of rosiglitazone. Therefore, these data suggest that a PPARgamma agonist increases expression of AdipoR2 and that insulin inhibits the expression of AdipoR2 through the PI3K pathway.