Generation of a lung squamous cell carcinoma three-dimensional culture model with keratinizing structures.

Tumor nests in lung squamous cell carcinoma (LUSC) have a hierarchical structure resembling squamous epithelium. The nests consist of basal-like cells on the periphery and layers of keratinocyte-like cells that differentiate towards the center of the nest, forming keratin pearls. Reproducing this spatial heterogeneity in in vitro models would be useful for understanding the biology of LUSC. Here, we established a three-dimensional (3D) culture model with a squamous epithelial structure using LUSC cell lines PLR327F-LD41 and MCC001F, established in-house. When PLR327F-LD41 cells were cultured in a mixture of Matrigel and collagen I, they generated 3D colonies (designated cancer organoids, or COs) with involucrin (IVL)-positive keratinizing cells in the center (IVLinner COs). COs with uniform size were generated by seeding PLR327F-LD41 cells in a form of small cell aggregates. Since Notch signaling induces the differentiation of squamous epithelium, we confirmed the effect of γ-secretase inhibitor in inhibiting Notch signaling in IVLinner COs. Surprisingly, γ-secretase inhibitor did not block induction of IVL-positive cells; however, cells residing between the CK5-positive basal-like layer and IVL-positive layer decreased significantly. Thus, our 3D culture model with uniform size and structure promises to be a useful tool for elucidating the biology of LUSC and for screening drug-candidates.

Azelnidipine Inhibits the Differentiation and Activation of THP-1 Macrophages through the L-Type Calcium Channel.

AIM: Recently, calcium channel blockers (CCBs) have been reported to reduce atherosclerosis with anti-inflammatory or antiatherosclerotic effects in vivo. It is well established that monocytes and macrophages play important roles in promoting atherosclerosis. However, the effects of CCBs on macrophage activation remain unclear. The aim of this study was to evaluate the effects of azelnidipine, a dihydropyridine L-type CCB, on the activation of macrophages and to clarify the mechanisms of the effects of CCBs on atherosclerosis. METHODS: THP-1 monocytes, a human leukemic cell line, were stimulated with 50 ng/mL of phorbol-12-myristate-13-acetate (PMA) 1 h after pretreatment with 10 µM azelnidipine or dimethyl sulfoxide (DMSO), and harvested. RESULTS: Azelnidipine blocked the expression of intercellular adhesion molecule-1 quantified by FACS analysis. The expression levels of Apo E and MMP9, which are markers of macrophage differentiation, were inhibited by azelnidipine as evaluated by quantitative RT-PCR. The level of LOX-1 mRNA, a scavenger receptor, was also reduced significantly by pretreatment with 10 µM azelnidipine. Azelnidipine also lowered the uptake of acetylated LDL. The expression of the L-type calcium channel Cav1.2 was 10-fold higher after 24 h of PMA stimulation. A knockdown of the CACNA1C gene, which encodes Cav1.2 protein in humans, with siRNA blocked the effect of reducing adhesion by azelnidipine, indicating that the effects of azelnidipine on macrophage differentiation were expressed through the CACNA1C gene. CONCLUSION: Our results suggest that azelnidipine has potent antiatherosclerotic properties by inhibition of macrophage activation through Cav1.2.

Hypercholesterolemia Causes Circadian Dysfunction: A Potential Risk Factor for Cardiovascular Disease.

Hypercholesterolemia is a well-known risk factor for a wide range of diseases in developed countries. Here, we report that mice lacking functional LDLR (low density lipoprotein receptor), an animal model of human familial hypercholesterolemia, show circadian abnormalities. In free running behavioral experiments in constant darkness, these mice showed a prolonged active phase and distinctly bimodal rhythms. Even when the circadian rhythms were entrained by light and dark cycles, these mice showed a significant attenuation of behavioral onset intensity at the start of the dark period. Further, we hypothesized that the combination of hypercholesterolemia and circadian abnormalities may affect cardiovascular disease progression. To examine this possibility, we generated LDLR-deficient mice with impaired circadian rhythms by simultaneously introducing a mutation into Period2, a core clock gene, and found that these mice showed a significant enlargement of artery plaque area with an increase in inflammatory cytokine IL-6 levels. These results suggest that circadian dysfunction may be associated with the development or progression of cardiovascular diseases.

EGCG, a green tea catechin, attenuates the progression of heart failure induced by the heart/muscle-specific deletion of MnSOD in mice.

BACKGROUND: Manganese superoxide dismutase (MnSOD) is an important antioxidant enzyme affected in heart/muscle-specific MnSOD-deficient mice (H/M-SOD2-/-), which develop progressive congestive heart failure and exhibit pathology typical of dilated cardiomyopathy. METHODS: In this study we investigated the beneficial effects of epigallocatechin gallate (EGCG) on the cardiac remodeling and telomere biology in H/M-SOD2-/- mice. H/M-SOD2-/- mice were divided into three groups: those receiving normal drinking water (KO), a low dose of EGCG (L: 10mg/L), and a high dose of EGCG (H: 100mg/L) beginning at eight weeks of age and lasting for eight weeks. RESULTS: The mice in the KO group exhibited significantly dilated cardiac remodeling with reduced contractility, which was prevented by the administration of EGCG. Although the mortality of KO mice was about 50% at 16 weeks of age, the mice that received EGCG had a high survival rate. The cardiac dilatation with reduced cardiac contraction in KO mice was prevented by EGCG treatment. The levels of myocardial oxidative stress and free fatty acids were lower in the group treated with EGCG compared with the KO group. The increased expression of nitric oxide synthase 2, nitrotyrosine, fatty acid synthase, Toll-like receptor 4, and Sirt1 in the KO mice were prevented by EGCG treatment. The shortening of the telomere length, decreased telomerase activity in KO mice were also prevented by EGCG. CONCLUSIONS: H/M-SOD2-/- mice receiving EGCG have a lower mortality rate and exhibit less inflammation and a better preserved cardiac function and telomere biology.

Deletion of Apoptosis Inhibitor of Macrophage (AIM)/CD5L Attenuates the Inflammatory Response and Infarct Size in Acute Myocardial Infarction.

BACKGROUND: An excessive inflammatory response after myocardial infarction (MI) increases myocardial injury. The toll-like receptor (TLR)-4 is activated by the recognition of endogenous ligands and is proinflammatory when there is myocardial tissue injury. The apoptosis inhibitor of the macrophage (AIM) is known to provoke an efflux of saturated free fatty acids (FFA) due to lipolysis, which causes inflammation via the TLR-4 pathway. Therefore, this study investigated the hypothesis that AIM causes a proinflammatory response after MI. METHODS AND RESULTS: The left anterior descending coronary artery was ligated to induce MI in both AIM-knockout (AIM(-/-)) and wild-type (WT) mice. After 3 days, the inflammatory response from activation of the TLR-4/NFκB pathway was assessed, and infarct size was measured by staining with triphenyltetrazolium chloride. In addition, left ventricular remodeling was examined after 28 days. Although the area at risk was similar between AIM(-/-) and WT mice, the infarct size was significantly smaller in AIM(-/-) mice (P=0.02). The heart weight-to-body weight ratio and myocardial fibrosis were also decreased in the AIM(-/-) mice, and the 28-day survival rate was improved (P<0.01). With the reduction of plasma FFA in AIM(-/-) mice, myocardial IRAK4 and NFκB activity were decreased (all P<0.05). Moreover, there was a reduction in myeloperoxidase activity and inducible nitric oxide synthase as part of the inflammatory response (P<0.01, P=0.03, respectively). Furthermore, NFκB DNA-binding activation via TLR-4, neutrophil infiltration, and inflammatory mediators were decreased in AIM(-/-) mice. CONCLUSIONS: The deletion of AIM reduced the inflammatory response and infarct size and improved survival after myocardial infarction.

Pentraxin-3 regulates the inflammatory activity of macrophages.

BACKGROUND AND AIMS: Pentraxin-3 (PTX3) reportedly has protective roles in atherosclerosis and myocardial infarction, and is a useful biomarker of vascular inflammation. However, the detailed functions of PTX3 in inflammation are yet to be elucidated. This study aimed to investigate the function of PTX3 in macrophages. METHODS: PMA-treated THP-1 cell line (THP-1 macrophage) and monocyte-derived human primary macrophages were treated with recombinant PTX3. Cytokine and chemokine levels in the THP-1 culture medium were measured as well as monocyte chemoattractant protein (MCP-1) concentrations in the Raw 264.7 cell culture medium. PTX3-silenced apoptotic macrophages (THP-1 cell line) were generated to investigate the roles of PTX3 in phagocytosis. RESULTS: In the presence of PTX3, macrophage interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α) and MCP-1 levels were reduced significantly (-39%, P=0.007; -21%, P=0.008; and -67%, P=0.0003, respectively), whilst activated transforming growth factor-ß (TGF-ß) was detected in the THP-1 macrophages (P=0.0004). Additionally, PTX3 induced Akt phosphorylation and reduced nuclear factor-kappa B (NF-κB) activation by 35% (P=0.002), which was induced by TNF-α in THP-1 macrophages. Furthermore, silencing of PTX3 in apoptotic cells resulted in increased macrophage binding, elevated expression rate of HLA-DR (+30%, P=0.015) and CD86 (+204%, P=0.004) positive cells, and induction of IL-1ß (+36%, P=0.024) production. Conversely, adding recombinant PTX3 to macrophages reduced CD86 and HLA-DR expression in a dose-dependent manner. CONCLUSIONS: We identified PTX3 as a novel regulator of macrophage activity, and this function suggests that PTX3 acts to resolve inflammation.

The relationship between neutrophil to lymphocyte ratio, endothelial function, and severity in patients with obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is characterized by repetitive intermittent hypoxia and reoxygenation during sleep with elevated oxidative stress and promotes the development of atherosclerosis, as demonstrated by vascular dysfunction and chronic inflammation. An increased neutrophil to lymphocyte ratio (NLR) has been recognized to be a novel inflammatory biomarker for systemic inflammation. OBJECTIVES: We evaluated whether the NLR reflects the severity of OSA and if continuous positive airway pressure (CPAP) treatment ameliorates the endothelial function and NLR in patients with OSA. METHODS: We enrolled 95 patients with suspected OSA and 29 patients who received CPAP therapy for 3 months. We evaluated the number of endothelial progenitor cells (EPCs) and NLR, the levels of nitric oxide (NOx) and asymmetric dimethylarginine (ADMA), and the endothelial function according to the flow-mediated dilatation (FMD) before and after CPAP treatment. RESULTS: The levels of apnea-hypopnea index demonstrated an inverse relationship with the FMD and a positive relationship with the NLR. Moreover, NLR is an independent factor suggested for the presence of severe OSA. CPAP therapy increased the levels of EPC and NOx and decreased the level of ADMA. CPAP treatment also improved the FMD and decreased the NLR. CONCLUSIONS: NLR and endothelial dysfunction significantly correlates with the severity of OSA and FMD and other biochemical parameters improved and NLR decreased significantly after CPAP treatment.

Acute effects of statin on reduction of angiopoietin-like 2 and glyceraldehyde-derived advanced glycation end-products levels in patients with acute myocardial infarction: a message from SAMIT (Statin for Acute Myocardial Infarction Trial).

Experimental ischemia-reperfusion models have shown that 3-hydroxy-3methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, have cardioprotective effects. SAMIT (Statin Acute Myocardial Infarction Trial) is a multicenter prospective open randomized trial, designed to evaluate the effects of statin treatment from the earliest stage on cardioprotection in patients with acute myocardial infarction (AMI). Patients were randomly assigned to receive atorvastatin (initial dose of 40 mg at admission followed by the maintenance dose of 10 mg/day for 30 days) or not (control), and then immediately underwent percutaneous coronary intervention (PCI) for the culprit lesion. The primary endpoints were infarct size and left ventricular function. The secondary endpoints were major adverse cardiac and cerebrovascular events (MACCE) and various biomarkers. There were no significant differences in baseline characteristics between 2 groups of the statin treatment group and the control group. The left ventricular ejection fraction increased at 6 months after the onset of AMI, compared with the baseline level in the atorvastatin group (P < 0.05), while it did not change in the control group. Although there were no significant differences in the MACCE, the changes in the levels of angiopoietin-like protein 2 (ANGPTL2) (P < 0.05), and glyceraldehyde-derived advanced glycation end-products, (TAGE) (P < 0.01) were suppressed at 2 weeks in the atorvastatin group, compared with the control group. Statin therapy started early after the onset reduced the levels of ANGPTL2 and TAGE, and thus, might have cardioprotective effects in patients with AMI.

Possible effects of glimepiride beyond glycemic control in patients with type 2 diabetes: a preliminary report.

BACKGROUND: The purpose of this study was to elucidate the effects of glimepiride on the levels of biomarkers related to cardiovascular regulation in patients with type 2 diabetes mellitus. METHODS AND RESULTS: Thirty-four patients with type 2 diabetes received glimepiride for 24 weeks. Significant decreases in the levels of glyceraldehyde-derived advanced glycation end products, (glycer-AGE: toxic AGE), eotaxin and fibroblast growth factor (FGF)-2 were recognized after the administration of glimepiride. Moreover, there were trends for there to be increases in the levels of granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage-colony stimulating factor (GM-CSF), and decreases in the levels of fractalkine, soluble CD40 ligand (sCD40L), macrophage inflammatory protein (MIP)-ß, vascular endothelial growth factor (VEGF) and soluble receptor for AGE (sRAGE). CONCLUSIONS: Glimepiride may have potent anti-oxidative, anti-inflammatory and angiogenic properties and it may potentially repair tissue damage by decreasing the levels of toxic AGE and increasing colony-stimulating factors.

Hepatitis A outbreak associated with a revolving sushi bar in Chiba, Japan: Application of molecular epidemiology.

AIM: The number of hepatitis A cases in Japan as well as in other developed countries has been progressively decreasing during the last several years. There is no universal hepatitis A vaccination program in Japan, and a hepatitis A virus (HAV) epidemic in Japan is not unlikely. In 2011, a hepatitis A outbreak associated with a revolving sushi bar occurred in Chiba, Japan. We aimed to analyze this outbreak. METHODS: Twenty-seven patients associated with this outbreak were admitted to the National Hospital Organization Chiba Medical Center. Molecular epidemiologic investigations were conducted. RESULTS: Twenty-six of the 27 patients had gone to the same revolving sushi bar, and then clinical symptoms appeared. HAV RNA was detected by reverse transcription polymerase chain reaction in 23 of the 27 (85.1%) patients whose sera had tested positive for anti-HAV immunoglobulin M. All isolates from this outbreak were clustered within subgenotype IA, displaying 100% sequence homology with each other in 232 bp from all 23 patients. All isolates belong to the IA-1 sublineage, which is endemic to Japan. CONCLUSION: A revolving sushi bar was associated with a hepatitis A outbreak, and molecular epidemiological investigations proved useful.

The glucagon-like peptide 1 analog liraglutide reduces TNF-α-induced oxidative stress and inflammation in endothelial cells.

OBJECTIVE: Glucagon-like peptide 1 (GLP-1), one of the incretin hormones, has been reported to increase positive inotropic activity in cardiac myocytes and protect against myocardial injury. However, the effects upon endothelial cells and the mechanisms involved are not fully understood. We assessed the hypothesis that GLP-1 has protective effects against inflammation and oxidative stress on human endothelial cells. METHODS AND RESULTS: The effects of the GLP-1 analog liraglutide upon TNF-α-induced injury of the human umbilical vein endothelial cells (HUVECs) were evaluated. First, ROS induced by TNF-α was measured by staining with CM-H(2)DCFDA. Intracellular ROS production of HUVECs was significantly decreased in a dose-dependent manner until 30 nM while liraglutide inhibited the induction of gp91(phox) and p22(phox), subunit of NADPH oxidase, by TNF-α. In addition, protein levels of SOD-2, catalase and GPx were significantly increased by liraglutide. Second, rapid translocation of PKC-α into the membrane following TNF-α was evident. Liraglutide significantly inhibited this very rapid TNF-α-induced translocation of PKC-α into membrane at 2.5 min. Third, liraglutide significantly inhibited NF-κB activation and upregulated I-κB family while phosphorylation of IKK-α/ß, which is upstream of NF-κB signaling, was also downregulated after 15 min of TNF-α treatment. Finally, liraglutide inhibited apoptosis of HUVEC and expression of Pentraxin-3 induced by TNF-α. CONCLUSION: Liraglutide exerts marked anti-oxidative and anti-inflammatory effects on endothelial cells with inhibition of PKC-α, NADPH oxidase, NF-κB signaling and upregulation of protective anti-oxidative enzymes.

HMG-CoA reductase inhibitor augments the serum total cholesterol-lowering effect of human adipose tissue-derived multilineage progenitor cells in hyperlipidemic homozygous Watanabe rabbits.

Familial hypercholesterolemia (FH) is an autosomal codominant disease characterized by high concentrations of proatherogenic lipoproteins secondary to deficiency in low-density lipoprotein (LDL) receptor. We reported recently the use of in situ stem cell therapy of human adipose tissue-derived multilineage progenitor cells (hADMPCs) in lowering serum total cholesterol in the homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits, an animal model of homozygous FH. Here we demonstrate that pravastatin, an HMG-CoA reductase inhibitor, augmented the cholesterol-lowering effect of transplanted hADMPCs and enhanced LDL clearance in homozygous WHHL rabbit. The results suggest the potential beneficial effects of in situ stem cell therapy in concert with appropriately selected pharmaceutical agents, in regenerative medicine.

Cationized gelatin-HVJ envelope with sodium borocaptate improved the BNCT efficacy for liver tumors in vivo.

BACKGROUND: Boron neutron capture therapy (BNCT) is a cell-selective radiation therapy that uses the alpha particles and lithium nuclei produced by the boron neutron capture reaction. BNCT is a relatively safe tool for treating multiple or diffuse malignant tumors with little injury to normal tissue. The success or failure of BNCT depends upon the 10B compound accumulation within tumor cells and the proximity of the tumor cells to the body surface. To extend the therapeutic use of BNCT from surface tumors to visceral tumors will require 10B compounds that accumulate strongly in tumor cells without significant accumulation in normal cells, and an appropriate delivery method for deeper tissues.Hemagglutinating Virus of Japan Envelope (HVJ-E) is used as a vehicle for gene delivery because of its high ability to fuse with cells. However, its strong hemagglutination activity makes HVJ-E unsuitable for systemic administration.In this study, we developed a novel vector for 10B (sodium borocaptate: BSH) delivery using HVJ-E and cationized gelatin for treating multiple liver tumors with BNCT without severe adverse events. METHODS: We developed cationized gelatin conjugate HVJ-E combined with BSH (CG-HVJ-E-BSH), and evaluated its characteristics (toxicity, affinity for tumor cells, accumulation and retention in tumor cells, boron-carrying capacity to multiple liver tumors in vivo, and bio-distribution) and effectiveness in BNCT therapy in a murine model of multiple liver tumors. RESULTS: CG-HVJ-E reduced hemagglutination activity by half and was significantly less toxic in mice than HVJ-E. Higher 10B concentrations in murine osteosarcoma cells (LM8G5) were achieved with CG-HVJ-E-BSH than with BSH. When administered into mice bearing multiple LM8G5 liver tumors, the tumor/normal liver ratios of CG-HVJ-E-BSH were significantly higher than those of BSH for the first 48 hours (p < 0.05). In suppressing the spread of tumor cells in mice, BNCT treatment was as effective with CG-HVJ-E-BSH as with BSH containing a 35-fold higher 10B dose. Furthermore, CG-HVJ-E-BSH significantly increased the survival time of tumor-bearing mice compared to BSH at a comparable dosage of 10B. CONCLUSION: CG-HVJ-E-BSH is a promising strategy for the BNCT treatment of visceral tumors without severe adverse events to surrounding normal tissues.

Anti-inflammatory properties of azelnidipine, a dihydropyridine-based calcium channel blocker.

Accumulating evidence suggests that inflammation as well as oxidative stress play essential roles in atherogenesis, progression of atherosclerosis, and plaque instability and rupture. Recent studies on available anti-hypertensive agents have focused on their anti-atherosclerotic effects over and above their blood pressure lowering action. These studies have included investigations on several types of calcium channel blockers, with several investigations indicating that a dihydropiridine-based calcium channel blocker, azelnidipine, developed in Japan, has unique anti-oxidative properties. An anti-inflammatory effect of azelnidipine has, however, yet to be established and therefore we carried out a series of in vivo and in vitro studies to investigate this possibility. This was achieved by measuring inflammatory and oxidative stress markers in 16 high risk hypertensive patients administered 16mg/day of azelnidipine. After 4 weeks of treatment, serum levels of hsCRP, IL-6, and IL-8 and urinary 8-OHdG were decreased significantly, despite blood pressure remaining unchanged. Cultures of human mononuclear leukocytes collected from six healthy volunteers showed 100 nM of azelnidipine caused significant inhibition of formyl-methyonyl leucyl phenylalanine (fMLP)-induced production of IL-8. Taken together, these results suggest that azelnidipine has anti-inflammatory effects independent of its anti-hypertensive action. As leukocytes do not possess voltage-operated calcium channels, the effect of azelnidipine in these cells appears to occur independently of an L-type calcium channel antagonizing effect.

Properties of hepatocyte-like cell clusters from human adipose tissue-derived mesenchymal stem cells.

There are only a few reports that describe the hepatocytic differentiation potential of human adipose tissue-derived mesenchymal stem cells (hADMSCs) and no reports that describe the in vivo functions of hepatocyte-like cells differentiated from somatic stem cells including hADMSCs. In this study, we established a new method for generation of functional hepatocyte-like cell clusters using floating culture method and induced functional hepatocyte-like cell clusters, which functioned effectively not only in vitro but also in vivo. The generated hepatocyte-like cell clusters were characterized by gene expression analysis, functional assays, and transplantation into non-obese diabetic severe combined immunodeficiency (NOD-SCID) mouse with chronic liver injury. The generated hepatocyte-like cell clusters expressed various genes normally found on mature hepatocytes. The cell clusters exhibited functional characteristics of hepatocytes: they expressed albumin, secreted urea, had cytochrome P450 activity, could take up low-density lipoprotein, and stored glycogen. Transplantation of these cell clusters into NOD-SCID mouse with chronic liver injury resulted in a significant improvement of serum albumin and total bilirubin levels. In summary, we established a new protocol for efficient induction of hADMSCs into functional hepatocyte-like cell clusters.

Cardiomyoblast-like cells differentiated from human adipose tissue-derived mesenchymal stem cells improve left ventricular dysfunction and survival in a rat myocardial infarction model.

Adipose tissue-derived mesenchymal stem cells (ADMSCs) are multipotent cells. Here we examined whether human ADMSCs (hADMSCs) could differentiate into cardiomyoblast-like cells (CLCs) by induction with dimethylsulfoxide and whether the cells would be utilized to treat cardiac dysfunction. Dimethylsulfoxide induced the expression of various cardiac markers in hADMSCs, such as alpha-cardiac actin, cardiac myosin light chain, and myosin heavy chain; none of which were detected in noncommitted hADMSCs. The induced cells were thus designated as hADMSC-derived CLCs (hCLCs). To confirm their beneficial effect on cardiac function, hCLC patches were transplanted onto the Nude rat myocardial infarction model, and compared with noncommitted hADMSC patch transplants and sham operations. Echocardiography demonstrated significant short-term improvement of cardiac function in both the patch-transplanted groups. However, long-term follow-up showed rescue and maintenance of cardiac function in the hCLC patch-transplanted group only, but not in the noncommitted hADMSC patch-transplanted animals. The hCLCs, but not the hADMSCs, engrafted into the scarred myocardium and differentiated into human cardiac troponin I-positive cells, and thus regarded as cardiomyocytes. Transplantation of the hCLC patches also resulted in recovery of cardiac function and improvement of long-term survival rate. Thus, transplantation of hCLC patches is a potentially effective therapeutic strategy for future cardiac tissue regeneration.

Reduction of N-glycolylneuraminic acid xenoantigen on human adipose tissue-derived stromal cells/mesenchymal stem cells leads to safer and more useful cell sources for various stem cell therapies.

Adipose tissue is an attractive source for somatic stem cell therapy. Currently, human adipose tissue-derived stromal cells/mesenchymal stem cells (hADSCs/MSCs) are cultured with fetal bovine serum (FBS). Recently, however, not only human embryonic stem cell lines cultured on mouse feeder cells but also bone marrow-derived human MSCs cultured with FBS were reported to express N-glycolylneuraminic acid (Neu5Gc) xenoantigen. Human serum contains high titers of natural preformed antibodies against Neu5Gc. We studied the presence of Neu5Gc on hADSCs/MSCs cultured with FBS and human immune response mediated by Neu5Gc. Our data indicated that hADSCs/MSCs cultured with FBS expressed Neu5Gc and that human natural preformed antibodies could bind to hADSCs/MSCs. However, hADSCs/MSCs express complement regulatory proteins such as CD46, CD55, and CD59 and are largely resistant to complement-mediated cytotoxicity. hADSCs/MSCs cultured with FBS could be injured by antibody-dependent cell-mediated cytotoxicity mechanism. Further, human monocyte-derived macrophages could phagocytose hADSCs/MSCs cultured with FBS and this phagocytic activity was increased in the presence of human serum. Culturing hADSCs/MSCs with heat-inactivated human serum for a week could markedly reduce Neu5Gc on hADSCs/MSCs and prevent immune responses mediated by Neu5Gc, such as binding of human natural preformed antibodies, antibody-dependent cell-mediated cytotoxicity, and phagocytosis. Adipogenic and osteogenic differentiation potentials of hADSCs/MSCs cultured with heat-inactivated human serum were not less than that of those cultured with FBS. For stem cell therapies based on hADSCs/MSCs, hADSCs/MSCs that presented Neu5Gc on their cell surfaces after exposure to FBS should be cleaned up to be rescued from xenogeneic rejection.

Transdifferentiation of human adipose tissue-derived stromal cells into insulin-producing clusters.

Type 1 diabetes mellitus is caused by autoimmune destruction of insulin-producing beta cells. The major obstacle to transplantation of insulin-producing cells to cure the disease is the limited source of these cells. To overcome this problem, we describe here a multistep protocol for generation of insulin-producing islet-like clusters from human adipose tissue-derived stromal cells (ADSCs). Analysis using reverse transcription polymerase chain reaction detected enhanced expression of various pancreatic genes during the differentiation of ADSCs. Immunofluorescence analysis revealed functional similarities between cells derived from ADSCs and pancreatic islet cells, i.e., the presence of insulin- and C-peptide-coexpressing cells in the clusters and glucagon expression on the cell surface. The glucose challenge tests revealed the production of insulin, and such production was regulated via physiological signaling pathways. Our insulin-producing cells derived from ADSCs could be potentially used for cell therapy of type 1 diabetes mellitus.

Creation of a rich subcutaneous vascular network with implanted adipose tissue-derived stromal cells and adipose tissue enhances subcutaneous grafting of islets in diabetic mice.

Subcutaneous tissue was proposed as an optimal transplant site for islets in treatment for type I diabetes mellitus. However, vascular networks in subcutaneous tissue are too poor in their natural state to allow survive and function of the transplanted graft. This study examined whether subcutaneous implantation of adipose tissue-derived stromal cells (ADSCs) combined with minced adipose tissue could form vascular-rich beds suitable to support islet transplantation. ADSCs were isolated from male C57BL/6J mouse inguinal subcutaneous adipose tissue. ADSCs and minced adipose tissue were implanted syngeneically in subcutaneous tissue of the back of recipient mice. Four weeks later, vascularization in the implanted subcutaneous tissue was evaluated, and islets were transplanted onto the vascularized pockets. Mice that received ADSCs mixed with minced adipose tissue showed a richly vascularized pocket of tissue with significantly higher capillary density than in mice implanted with either ADSCs or minced adipose tissue only. All recipient mice of the combination ADSCs and minced adipose tissue group showed correction in blood glucose level within a week after islet transplantation and maintained normoglycemia for over 8 weeks. These mice became hyperglycemic again after removal of the subcutaneous grafts. This novel method will expand the indications for islet transplant therapy and potential clinical application of cell-based therapy.