Erratum: Chen, Y.-R., et al. Improvement of Impaired Motor Functions by Human Dental Exfoliated Deciduous Teeth Stem Cell-Derived Factors in a Rat Model of Parkinson's Disease. Int. J. Mol. Sci. 2020, 21, 3807.

The authors regret to have made a mistake in publishing this paper [...].

Development of polydimethylsiloxane-based biomimetic scaffolds with cylinder micropillars for retinal pigment epithelial cell cultivation.

BACKGROUND: Age-related macular degeneration (AMD) is one of the leading causes of vision loss. Once the retinal pigment epithelium (RPE) layers are destroyed, the poor visual acuity and recognition are generally irreversible. Cell therapy that possesses enormous potential in regenerative medicine may provide an alternative treatment for several incurable diseases such as AMD. In this study, we developed an innovative polydimethylsiloxane (PDMS)-based biomimetic scaffolds with cylinder micropillars for the cultivation of induced pluripotent stem cell-derived RPEs (iPSC-RPEs). RPEs were cultured on the PDMS-based biomimetic scaffolds and validated the cells gene expression. METHODS: The biomimetic PDMS scaffold was fabricated through spin coating and lithography method. It was further modified on surface with biomolecules to improve cell affinity and stability. The iPSC-RPEs were seeded on the scaffold and analyzed with characteristic gene expression. RESULTS: PDMS biomimetic scaffold was analyzed with Fourier transform infrared spectroscopy and proved its chemical composition. iPSC-RPEs demonstrated confluent cell monolayer on the scaffold and maintained RPE-specific gene expression, which proved the PDMS-based biomimetic scaffold to be supportive for iPSC-RPEs growth. CONCLUSION: The PDMS interface allowed regular growth of iPSC-RPEs and the design of cylinder micropillars further provided the bioscaffold high motion resistance may improve the engraftment stability of iPSC-RPEs after transplantation. Taken together, this innovative PDMS-based biomimetic scaffold may serve as an ideal interface for in vitro iPSC-RPE cultivation and subsequent transplantation in vivo. This novel device exhibits better bioavailability than conventional injection of donor cells and may be an alternative option for the treatment of AMD.

Improvement of Impaired Motor Functions by Human Dental Exfoliated Deciduous Teeth Stem Cell-Derived Factors in a Rat Model of Parkinson's Disease.

Parkinson's disease (PD) is a long-term degenerative disease of the central nervous system (CNS) that primarily affects the motor system. So far there is no effective treatment for PD, only some drugs, surgery, and comprehensive treatment can alleviate the symptoms of PD. Stem cells derived from human exfoliated deciduous teeth (SHED), mesenchymal stem cells derived from dental pulp, may have promising potential in regenerative medicine. In this study, we examine the therapeutic effect of SHED-derived conditioned medium (SHED-CM) in a rotenone-induced PD rat model. Intravenous administration of SHED-CM generated by standardized procedures significantly improved the PD symptoms accompanied with increased tyrosine hydroxylase amounts in the striatum, and decreased α-synuclein levels in both the nigra and striatum, from rotenone-treated rats. In addition, this SHED-CM treatment decreased both Iba-1 and CD4 levels in these brain areas. Gene ontology analysis indicated that the biological process of genes affected by SHED-CM was primarily implicated in neurodevelopment and nerve regeneration. The major constituents of SHED-CM included insulin-like growth factor binding protein-6 (IGFBP-6), tissue inhibitor of metalloproteinase (TIMP)-2, TIMP-1, and transforming growth factor 1 (TGF-1). RNA-sequencing (RNA-seq) and Ingenuity Pathway Analysis (IPA) revealed that these factors may ameliorate PD symptoms through modulating the cholinergic synapses, calcium signaling pathways, serotoninergic synapses, and axon guidance. In conclusion, our data indicate that SHED-CM contains active constituents that may have promising efficacy to alleviate PD.

CircularRNA as novel biomarkers in liver diseases.

The liver is an essential organ that is primarily responsible for digestion and eliminating toxic substances from the body. After the industrial revolution, Western diet and lifestyle changes have increased the incidence of several liver diseases, including non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), liver cirrhosis, and hepatocellular carcinoma (HCC). NAFLD and NASH are mostly asymptomatic at early stages, and the disease progression from NAFLD to life-threatening HCC remains not fully understood. Circular RNA (circRNA) is consist of a circular structure, and the circRNA-microRNA(miRNA)-mRNA axes have been shown to be involved in several cellular events, including apoptosis, vascularization, metastasis, etc. The highly stable structure of circRNAs has enabled themselves to be used as putative biomarkers of several diseases. Here, we conducted a literature review and discussed the identified roles of circRNAs in NAFLD, NASH, liver cirrhosis, and HCC. For example, deficiency of circRNA_0046366 and circRNA_0046367 has been shown as the characteristics of NAFLD, and restoration of these circRNAs ameliorates the oxidative stress, lipotoxicity, and disease severity in NAFLD. Silencing of circ_0071410 was shown to alleviate hepatic stellate activation, the key step of liver cirrhosis. CDR1 and circ_0067934 can facilitate the invasion and metastasis of HCC, while circMTO1 negatively regulates the progression of HCC. Although several research works have been conducted, the whole picture of circRNA-related underlying mechanisms is unclear. Future works using high-throughput bioinformatic approaches will be needed to delineate the role of circRNAs in liver diseases and to further develop novel diagnostics and therapeutics.

Dental Pulp Stem Cell-Derived Factors Alleviate Subarachnoid Hemorrhage-Induced Neuroinflammation and Ischemic Neurological Deficits.

Aneurysmal subarachnoid hemorrhage (aSAH), characterized by the extravasation of blood into the subarachnoid space caused by an intracranial aneurysm rupture, may lead to neurocognitive impairments and permanent disability and usually carries poor outcome. Dental or gingiva-derived stem cells have been shown to contribute to immune modulation and neuroregeneration, but the underlying mechanisms are unclear. In the present study, we sought to investigate whether dental pulp stem cells (DPSCs) secrete certain factor(s) that can ameliorate the neural damage and other manifestations in a rat aSAH model. Twenty-four hours after the induction of aSAH, microthrombosis, cortical vasoconstriction, and the decrease in microcirculation and tissue oxygen pressure were detected. Intrathecal administration of DPSC-derived conditioned media (DPSC-CM) ameliorated aSAH-induced vasoconstriction, neuroinflammation, and improved the oxygenation in the injured brain. Rotarod test revealed that the aSAH-induced cognitive and motor impairments were significantly improved by this DPSC-CM administration. Cytokine array indicated the major constituent of DPSC-CM was predominantly insulin growth factor-1 (IGF-1). Immunohistochemistry staining of injured brain tissue revealed the robust increase in Iba1-positive cells that were also ameliorated by DPSC-CM administration. Antibody-mediated neutralization of IGF-1 moderately deteriorated the rescuing effect of DPSC-CM on microcirculation, Iba1-positive cells in the injured brain area, and the cognitive/motor impairments. Taken together, the DPSC-derived secretory factors showed prominent therapeutic potential for aSAH. This therapeutic efficacy may include improvement of microcirculation, alleviation of neuroinflammation, and microglial activation; partially through IGF-1-dependent mechanisms.

Development of a Graphene Oxide-Incorporated Polydimethylsiloxane Membrane with Hexagonal Micropillars.

Several efforts have been made on the development of bioscaffolds including the polydimethylsiloxane (PDMS) elastomer for supporting cell growth into stable sheets. However, PDMS has several disadvantages, such as intrinsic surface hydrophobicity and mechanical strength. Herein, we generated a novel PDMS-based biomimetic membrane by sequential modifications of the PMDS elastomer with graphene oxide (GO) and addition of a hexagonal micropillar structure at the bottom of the biomembrane. GO was initially homogenously mixed with pure PDMS and then was further coated onto the upper surface of the resultant PDMS. The elastic modulus and hydrophilicity were significantly improved by such modifications. In addition, the development of hexagonal micropillars with smaller diameters largely improved the ion permeability and increased the motion resistance. We further cultured retinal pigment epithelial (RPE) cells on the surface of this modified PDMS biomembrane and assayed its biocompatibility. Remarkably, the GO incorporation and coating exhibited beneficial effect on the cell growth and the new formation of tight junctions in RPE cells. Taken together, this GO-modified PDMS scaffold with polyhexagonal micropillars may be utilized as an ideal cell sheet and adaptor for cell cultivation and can be used in vivo for the transplantation of cells such as RPE cells.

Inhibition of Arachidonate 12/15-Lipoxygenase Improves α-Galactosidase Efficacy in iPSC-Derived Cardiomyocytes from Fabry Patients.

(1) Background: A high incidence of intervening sequence (IVS)4+919 G>A mutation with later-onset cardiac phenotype have been reported in a majority of Taiwan Fabry cohorts. Some evidence indicated that conventional biomarkers failed to predict the long-term progression and therapeutic outcome; (2) Methods: In this study, we constructed an induced pluripotent stem cell (iPSC)-based platform from Fabry cardiomyopathy (FC) patients carrying IVS4+919 G>A mutation to screen for potential targets that may help the conventional treatment; (3) Results: The FC-patient-derived iPSC-differentiated cardiomyocytes (FC-iPSC-CMs) carried an expected IVS4+919 G>A genetic mutation and recapitulated several FC characteristics, including low α-galactosidase A enzyme activity and cellular hypertrophy. The proteomic analysis revealed that arachidonate 12/15-lipoxygenase (Alox12/15) was the most highly upregulated marker in FC-iPSC-CMs, and the metabolites of Alox12/15, 12(S)- and 15(S)-hydroxyeicosatetraenoic acid (HETE), were also elevated in the culture media. Late administration of Alox12/15 pharmacological inhibitor LOXBlock-1 combined with α-galactosidase, but not α-galactosidase alone, effectively reduced cardiomyocyte hypertrophy, the secretion of 12(S)- and 15(S)-HETE and the upregulation of fibrotic markers at the late phase of FC; (4) Conclusions: Our study demonstrates that cardiac Alox12/15 and circulating 12(S)-HETE/15(S)-HETE are involved in the pathogenesis of FC with IVS4+919 G>A mutation.

Improvement of non-alcoholic steatohepatitis by hepatocyte-like cells generated from iPSCs with Oct4/Sox2/Klf4/Parp1.

The prevalence of nonalcoholic fatty liver disease (NAFLD) is usually increased with age. Non-alcoholic steatohepatitis (NASH), a serious form of NAFLD, may lead to cirrhosis and end-stage liver diseases. Induced pluripotent stem cells (iPSCs) hold promising potential in personalized medicine. Although obviation of c-Myc reduces tumorigenic risk, it also largely reduced the generation of iPSCs. Recently, Poly(ADP-ribose) polymerase 1 (Parp1) has been reported to enhance cell reprogramming. In this study, we demonstrated that forced expression of Oct4/Sox2/Klf4/Parp1 (OSKP) effectively promoted iPSC generation from senescent somatic cells from 18-month-old mouse. The iPSCs presented regular pluripotent properties, ability to form smaller teratoma with smaller size, and the potential for tridermal differentiation including hepatocyte-like cells (OSKP-iPSC-Heps). Resembled to fetal hepatocytes but not senescent hepatocytes, these OSKP-iPSC-Heps possessed antioxidant ability and were resistant to oxidative insult induced by H2O2 or exogenous fatty acid. Intrasplenic transplantation of OSKP-iPSC-Heps ameliorated the triglyceride over-accumulation and hepatitis, prevented the production of inflammatory cytokines and oxidative substances, and reduced apoptotic cells in methionine/choline-deficient diet (MCDD)-fed mice. In conclusion, we demonstrated that Parp-1 promoted iPSC generation from senescent cells, which can be used for the treatment of NASH after hepatic-specific differentiation. These findings indicated that patient-derived iPSC-Heps may offer an alternative option for treatment of NASH and NASH-associated end-stage liver diseases.

Amelioration of serum 8-OHdG level by enzyme replacement therapy in patients with Fabry cardiomyopathy.

OBJECTIVES: The level of 8-hydroxy-2-deoxyguanosise (8-OHdG) is a marker of oxidative stress. The objective of this study was to evaluate the effect of enzyme replacement therapy (ERT) on the level of 8-OHdG in patients with Fabry cardiomyopathy and the clinical evolution of Fabry cardiomyopathy. METHODS: We measured the serum levels of 8-OHdG in 20 healthy control and 22 patients with Fabry cardiomyopathy before and after ERT. RESULTS: The mean lysoGb3 and 8-OHdG levels was significantly increased in patients with Fabry cardiomyopathy compared with that of control subjects (lysoGb3, 3.6 ± 1.1 nM vs. 0.4 ± 0.1 nM, p < 0.01; 8-OHdG, 4.5 ± 0.5 ng/mL vs. 3.4 ± 0.4 ng/mL, P < 0.05). The mean lysoGb3 and 8-OHdG levels was significantly reduced after ERT for 14.2 months (lysoGb3, 3.6 ± 1.1 nM vs. 2.9 ± 1.1 nM, P < 0.05; 8-OHdG, 4.5 ± 0.5 ng/mL to 4 ± 0.4 ng/mL, P < 0.05). These changes were accompanied by decreases in LVM and LVMI. CONCLUSIONS: We demonstrated that the serum 8-OHdG levels is increased in patients with Fabry cardiomyopathy (FC) and that successful management of FC with ERT is associated with a decrease in this oxidative stress marker. Serum 8-OHdG levels can be used not only as a noninvasive biomarker of oxidative stress in patients with FC but also an objective and quantitative parameter in the follow-up of patients during ERT.

Interleukin-18 deteriorates Fabry cardiomyopathy and contributes to the development of left ventricular hypertrophy in Fabry patients with GLA IVS4+919 G>A mutation.

RATIONALE: A high incidence of GLA IVS4+919 G>A mutation in patients with Fabry disease of the later-onset cardiac phenotype, has been reported in Taiwan. However, suitable biomarkers or potential therapeutic surrogates for Fabry cardiomyopathy (FC) in such patients under enzyme replacement treatment (ERT) remain unknown. OBJECTIVE: Using FC patients carrying IVS4+919 G>A mutation, we constructed an induced pluripotent stem cell (iPSC)-based disease model to investigate the pathogenetic biomarkers and potential therapeutic targets in ERT-treated FC. RESULTS AND METHODS: The iPSC-differentiated cardiomyocytes derived from FC-patients (FC-iPSC-CMs) carried IVS4+919 G>A mutation recapitulating FC characteristics, including low α-galactosidase A enzyme activity, cellular hypertrophy, and massive globotriaosylceramide accumulation. Microarray analysis revealed that interleukin-18 (IL-18), a pleiotropic cytokine involved in various myocardial diseases, was the most highly upregulated marker in FC-iPSC-CMs. Meanwhile, IL-18 levels were found to be significantly elevated in the culture media of FC-iPSC-CMs and patients' sera. Notably, the serum IL-18 levels were highly paralleled with the progression of left ventricular hypertrophy in Fabry patients receiving ERT. Finally, using FC-iPSC-CMs as in vitro FC model, neutralization of IL-18 with specific antibodies combined with ERT synergistically reduced the secretion of IL-18 and the progression of cardiomyocyte hypertrophy in FC-iPSC-CMs. CONCLUSION: Our data demonstrated that cardiac IL-18 and circulating IL-18 are involved in the pathogenesis of FC and LVH. IL-18 may be a novel marker for evaluating ERT efficacy, and targeting IL-18 might be a potential adjunctive therapy combined with ERT for the treatment of advanced cardiomyopathy in FC patients with IVS4+919 G>A mutation.

Evaluation of Proinflammatory Prognostic Biomarkers for Fabry Cardiomyopathy With Enzyme Replacement Therapy.

BACKGROUND: Fabry disease (FD) causes progressive glycosphingolipid accumulation and damage in various organs, and several proinflammatory processes may be involved in this disease. Enzyme replacement therapy (ERT) can reduce the severity of Fabry cardiomyopathy (FC), but whether ERT could attenuate proinflammatory cytokines in FC remains unclear. In this study, we attempted to evaluate the efficacy of ERT on proinflammatory cytokines and vascular cell adhesion biomarkers. METHODS: We enrolled 25 patients with FC and administered ERT to them according to the present clinical guideline. We analyzed and compared echocardiographic and blood examination results between 25 patients with FD without left ventricular hypertrophy (LVH), 25 patients with FC with LVH who were receiving ERT, and 25 healthy age- and sex-matched controls. The parameters of cardiac function at baseline and 12 months after ERT were assessed through echocardiography, and the expression profiles of proinflammatory biomarkers were determined. RESULTS: Left ventricular mass (LVM), LVM index (LVMI), interventricular septal thickness at diastole, and serum levels of globotriaosylsphingosine (Gb3) were elevated in patients with FC. Meanwhile, several proinflammatory cytokines, including interleukin (IL)-6, IL-2, IL-1b, tumor necrosis factor-α, intercellular adhesion molecule, soluble vascular cell adhesion molecule, and monocyte chemoattractant protein-1 (MCP-1) were concomitantly increased. ERT significantly reduced these transthoracic echocardiographic parameters and lyso-Gb3 and proinflammatory cytokine levels. The changes in IL-6, MCP-1, and lyso-Gb3 levels were positively correlated with the change in LVMI. CONCLUSIONS: Our study has revealed that proinflammatory biomarkers, particularly IL-6 and MCP-1, may represent effective biomarkers for evaluating ERT outcomes in patients with FC.

Dysregulation of Mitochondrial Functions and Osteogenic Differentiation in Cisd2-Deficient Murine Induced Pluripotent Stem Cells.

Wolfram syndrome 2 (WFS2) is a premature aging syndrome caused by an irreversible mitochondria-mediated disorder. Cisd2, which regulates mitochondrial electron transport, has been recently identified as the causative gene of WFS2. The mouse Cisd2 knockout (KO) (Cisd2(-/-)) recapitulates most of the clinical manifestations of WFS2, including growth retardation, osteopenia, and lordokyphosis. However, the precise mechanisms underlying osteopenia in WFS2 and Cisd2 KO mice remain unknown. In this study, we collected embryonic fibroblasts from Cisd2-deficient embryos and reprogrammed them into induced pluripotent stem cells (iPSCs) via retroviral transduction with Oct4/Sox2/Klf4/c-Myc. Cisd2-deficient mouse iPSCs (miPSCs) exhibited structural abnormalities in their mitochondria and an impaired proliferative capability. The global gene expression profiles of Cisd2(+/+), Cisd2(+/-), and Cisd2(-/-) miPSCs revealed that Cisd2 functions as a regulator of both mitochondrial electron transport and Wnt/ß-catenin signaling, which is critical for cell proliferation and osteogenic differentiation. Notably, Cisd2(-/-) miPSCs exhibited impaired Wnt/ß-catenin signaling, with the downregulation of downstream genes, such as Tcf1, Fosl1, and Jun and the osteogenic regulator Runx2. Several differentiation markers for tridermal lineages were globally impaired in Cisd2(-/-) miPSCs. Alizarin red S staining and flow cytometry analysis further revealed that Cisd2(-/-) miPSCs failed to undergo osteogenic differentiation. Taken together, our results, as determined using an miPSC-based platform, have demonstrated that Cisd2 regulates mitochondrial function, proliferation, intracellular Ca(2+) homeostasis, and Wnt pathway signaling. Cisd2 deficiency impairs the activation of Wnt/ß-catenin signaling and thereby contributes to the pathogeneses of osteopenia and lordokyphosis in WFS2 patients.

Enhanced antioxidant capacity of dental pulp-derived iPSC-differentiated hepatocytes and liver regeneration by injectable HGF-releasing hydrogel in fulminant hepatic failure.

Acute hepatic failure (AHF) is a severe liver injury leading to sustained damage and complications. Induced pluripotent stem cells (iPSCs) may be an alternative option for the treatment of AHF. In this study, we reprogrammed human dental pulp-derived fibroblasts into iPSCs, which exhibited pluripotency and the capacity to differentiate into tridermal lineages, including hepatocyte-like cells (iPSC-Heps). These iPSC-Heps resembled human embryonic stem cell-derived hepatocyte-like cells in gene signature and hepatic markers/functions. To improve iPSC-Heps engraftment, we next developed an injectable carboxymethyl-hexanoyl chitosan hydrogel (CHC) with sustained hepatocyte growth factor (HGF) release (HGF-CHC) and investigated the hepatoprotective activity of HGF-CHC-delivered iPSC-Heps in vitro and in an immunocompromised AHF mouse model induced by thioacetamide (TAA). Intrahepatic delivery of HGF-CHC-iPSC-Heps reduced the TAA-induced hepatic necrotic area and rescued liver function and recipient viability. Compared with PBS-delivered iPSC-Heps, the HGF-CHC-delivered iPSC-Heps exhibited higher antioxidant and antiapoptotic activities that reduced hepatic necrotic area. Importantly, these HGF-CHC-mediated responses could be abolished by administering anti-HGF neutralizing antibodies. In conclusion, our findings demonstrated that HGF mediated the enhancement of iPSC-Hep antioxidant/antiapoptotic capacities and hepatoprotection and that HGF-CHC is as an excellent vehicle for iPSC-Hep engraftment in iPSC-based therapy against AHF.

Dexamethasone improves heat stroke-induced multiorgan dysfunction and damage in rats.

Dexamethasone (DXM) is known as an immunosuppressive drug used for inflammation control. In the present study, we attempted to examine whether DXM administration could attenuate the hypercoagulable state and the overproduction of pro-inflammatory cytokines, improve arterial hypotension, cerebral ischemia and damage, and vital organ failure in a rat model of heat stroke. The results indicated that all the rats suffering from heat stroke showed high serum levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß), accompanied with increased prothrombin time, activated partial thromboplastin time and D-D dimer, and decreased protein C. During the induction period of heat stroke, plasma levels of blood urea nitrogen (BUN), creatinine, glutamic oxaloacetic transaminase (SGOT), glutamic pyruvic transaminase (SGPT), and alkaline phosphatase (ALP), were consistently increased. High striatal levels of glycerol, glutamate, and lactate/pyruvate were simultaneously detected. On the contrary, the mean arterial pressure, plasma levels of interleukin-10 (IL-10), and local cerebral blood flow at the striatum were all decreased. Importantly, intravenous administration of DXM substantially ameliorated the circulatory dysfunction, systematic inflammation, hypercoagulable state, cerebral ischemia and damage during the induction period of heat stroke. These findings demonstrated that DXM may be an alternative therapy that can ameliorate heat stroke victims by attenuating activated coagulation, systemic inflammation, and vital organ ischemia/injury during heat stroke.

Intratumoral decorin gene delivery by AAV vector inhibits brain glioblastomas and prolongs survival of animals by inducing cell differentiation.

Glioblastoma multiforme (GBM) is the most malignant cancer in the central nervous system with poor clinical prognosis. In this study, we investigated the therapeutic effect of an anti-cancer protein, decorin, by delivering it into a xenograft U87MG glioma tumor in the brain of nude mice through an adeno-associated viral (AAV2) gene delivery system. Decorin expression from the AAV vector in vitro inhibited cultured U87MG cell growth by induction of cell differentiation. Intracranial injection of AAV-decorin vector to the glioma-bearing nude mice in vivo significantly suppressed brain tumor growth and prolonged survival when compared to control non-treated mice bearing the same U87MG tumors. Proteomics analysis on protein expression profiles in the U87MG glioma cells after AAV-mediated decorin gene transfer revealed up- and down-regulation of important proteins. Differentially expressed proteins between control and AAV-decorin-transduced cells were identified through MALDI-TOF MS and database mining. We found that a number of important proteins that are involved in apoptosis, transcription, chemotherapy resistance, mitosis, and fatty acid metabolism have been altered as a result of decorin overexpression. These findings offer valuable insight into the mechanisms of the anti-glioblastoma effects of decorin. In addition, AAV-mediated decorin gene delivery warrants further investigation as a potential therapeutic approach for brain tumors.

Chronic exposure to Rhodobacter sphaeroides extract Lycogen™ prevents UVA-induced malondialdehyde accumulation and procollagen I down-regulation in human dermal fibroblasts.

UVA contributes to the pathogenesis of skin aging by downregulation of procollagen I content and induction of matrix metalloproteinase (MMP)-associated responses. Application of antioxidants such as lycopene has been demonstrated as a convenient way to achieve protection against skin aging. Lycogen™, derived from the extracts of Rhodobacter sphaeroides, exerts several biological effects similar to that of lycopene whereas most of its anti-aging efficacy remains uncertain. In this study, we attempted to examine whether Lycogen™ could suppress malondialdehyde (MDA) accumulation and restore downregulated procollagen I expression induced by UVA exposure. In human dermal fibroblasts Hs68 cells, UVA repressed cell viability and decreased procollagen I protein content accompanied with the induction of MMP-1 and MDA accumulation. Remarkably, incubation with 50 µM Lycogen™ for 24 h ameliorated UVA-induced cell death and restored UVA-induced downregulation of procollagen in a dose-related manner. Lycogen™ treatment also prevented the UVA-induced MMP-1 upregulation and intracellular MDA generation in Hs68 cells. Activation of NFκB levels, one of the downstream events induced by UVA irradiation and MMP-1 induction, were also prevented by Lycogen™ administration. Taken together, our findings demonstrate that Lycogen™ may be an alternative agent that prevents UVA-induced skin aging and could be used in cosmetic and pharmaceutical applications.

Improvement of carbon tetrachloride-induced acute hepatic failure by transplantation of induced pluripotent stem cells without reprogramming factor c-Myc.

The only curative treatment for hepatic failure is liver transplantation. Unfortunately, this treatment has several major limitations, as for example donor organ shortage. A previous report demonstrated that transplantation of induced pluripotent stem cells without reprogramming factor c-Myc (3-genes iPSCs) attenuates thioacetamide-induced hepatic failure with minimal incidence of tumorigenicity. In this study, we investigated whether 3-genes iPSC transplantation is capable of rescuing carbon tetrachloride (CCl(4))-induced fulminant hepatic failure and hepatic encephalopathy in mice. Firstly, we demonstrated that 3-genes iPSCs possess the capacity to differentiate into hepatocyte-like cells (iPSC-Heps) that exhibit biological functions and express various hepatic specific markers. 3-genes iPSCs also exhibited several antioxidant enzymes that prevented CCl(4)-induced reactive oxygen species production and cell death. Intraperitoneal transplantation of either 3-genes iPSCs or 3-genes iPSC-Heps significantly reduced hepatic necrotic areas, improved hepatic functions, and survival rate in CCl(4)-treated mice. CCl(4)-induced hepatic encephalopathy was also improved by 3-genes iPSC transplantation. Hoechst staining confirmed the successful engraftment of both 3-genes iPSCs and 3-genes iPSC-Heps, indicating the homing properties of these cells. The most pronounced hepatoprotective effect of iPSCs appeared to originate from the highest antioxidant activity of 3-gene iPSCs among all transplanted cells. In summary, our findings demonstrated that 3-genes iPSCs serve as an available cell source for the treatment of an experimental model of acute liver diseases.

Endothelin-1 suppresses long-chain fatty acid uptake and glucose uptake via distinct mechanisms in 3T3-L1 adipocytes.

Endothelin-1 (ET-1) has been demonstrated to induce insulin resistance (IR) and lipolysis, raising the possibility that ET-1 may also contribute to the elevated fatty acid levels in IR-associated comorbidities. We attempted to evaluate whether ET-1 also affects the long-chain fatty acid (LCFA) utilization in 3T3-L1 adipocytes. The effects of chronic ET-1 exposure on basal and insulin-stimulated LCFA uptake, and LCFA uptake kinetics were examined in 3T3-L1 adipocytes. Chronic exposure to ET-1 induced IR and suppressed basal and insulin-stimulated LCFA uptake. Given that insulin acutely stimulates LCFA uptake, there was dramatically similar trend of dose-response curves for ET-1-suppressed LCFA uptake, and also similar corresponding IC50 values, between basal and insulin-stimulated states, reflecting that ET-1 predominantly suppresses basal LCFA uptake. Results of LCFA kinetics, western blots, and CD36 inhibition using sulfosuccinimidyl oleate (SSO) revealed that suppression of LCFA uptake by ET-1 is associated with downregulation of CD36. ET type A receptor (ET(A)R) antagonist BQ-610 reversed the IR induction and the ET-1-suppressed LCFA uptake. Exogenous replenishment of phosphatidylinositol (PI) 4, 5-bisphosphate (PIP2) prevented IR induction, but not the suppression of LCFA uptake by ET-1. Pharmacological inhibition of the activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) completely blocked the ET-1-suppressed LCFA uptake. Serving as an inducer of IR, ET-1 also chronically suppresses LCFA uptake via PIP2-independent and ERK-dependent pathway. The interplay between impaired glucose disposal and diminished LCFA utilization, induced by ET-1, could worsen the dysregulation of adipose metabolism and energy homeostasis in insulin-resistant states.

Enhanced long-chain fatty acid uptake contributes to overaccumulation of triglyceride in hyperinsulinemic insulin-resistant 3T3-L1 adipocytes.

The precise pathogenesis of obesity remains controversial. In obesity, diminished adipose glucose utilization suggests that some other substrates may be responsible for the adipose triglyceride (TG) overaccumulation. Here we attempted to evaluate if long-chain fatty acid (LCFA) flux was modulated by a physiologically relevant condition of hyperinsulinemia in 3T3-L1 adipocytes and if the altered LCFA influx might eventually contribute to the TG overaccumulation in obesity. The effects of prolonged insulin exposure to adipocytes on basal, insulin-stimulated LCFA uptake as well as intracellular LCFA metabolism were measured. Prolonged insulin exposure was found to induce insulin resistance (IR) yet enhance basal and insulin-stimulated LCFA uptake in normoglycemic condition, and the addition of high glucose exacerbated these abnormalities of both glucose and LCFA influx. Along with the enhanced LCFA uptake was an increase in the rates of intracellular LCFA deposition and incorporation into TG; but a decrease was found in basal and insulin-suppressive LCFA oxidation, as well as in isoproterenol-induced fatty acid efflux. Inhibition of either phosphatidylinositol 3-kinase or mitogen-activated protein kinase (MAPK) pathway did not prevent the induction of IR, whereas the enhanced basal and insulin-stimulated LCFA uptake was abrogated by inhibition of MAPK pathway. In hyperinsulinemic insulin-resistant 3T3-L1 adipocytes, basal and insulin-stimulated LCFA uptake tends to increase via a MAPK-dependent mechanism. The increment of LCFA influx predominantly accounts for TG overaccumulation, but not for mitochondrial oxidation, and is prone to retain within adipocytes. These findings may interpret the plausible mechanism of pathogenesis for obesity in hyperinsulinemia-associated IR.

Angiotensin II enhances insulin sensitivity in vitro and in vivo.

The renin-angiotensin system plays a critical role in the pathogenesis of obesity, obesity-associated hypertension, and insulin resistance. However, the biological actions of angiotensin II (AII) on insulin sensitivity remain controversial. Because angiotensinogen and AII receptors are expressed on adipose tissue, we investigated the effect of AII on the insulin sensitivity of isolated rat adipocytes. The results of a receptor binding assay showed the maximal AII binding capacity of adipocytes to be 8.3 +/- 0.9 fmol/7 x 10(6) cells and the dissociation constant to be 2.72 +/- 0.11 nM. Substantial expression of both type 1 and 2 AII (AT1 and AT2) receptors was detected by RT-PCR. AII had no effect on basal glucose uptake, but significantly potentiated insulin-stimulated glucose uptake; this effect was abolished by the AT1 antagonist, losartan. In addition, AII did not alter the insulin binding capacity of adipocytes, but increased insulin-stimulated tyrosine phosphorylation of the insulin receptor beta-subunit, Akt phosphorylation, and translocation of glucose transporter 4 to the plasma membrane. AII potentiated insulin-stimulated glucose uptake through the AT1 receptor and by alteration of the intracellular signaling of insulin. Intraperitoneal injection of Sprague Dawley rats with AII increased insulin sensitivity in vivo. In conclusion, we have shown that AII enhances insulin sensitivity both in vitro and in vivo, suggesting that dysregulation of the insulin-sensitizing effect of AII may be involved in the development of insulin resistance.