Engineering bispecific T-cell engagers to deplete eosinophils for the treatment of severe eosinophilic asthma.

Severe eosinophilic asthma (SEA) is characterized by elevated eosinophil counts in the blood and airway mucosa. While monoclonal antibody therapies targeting interleukin-5 (IL-5) and its receptor (IL-5Rα) have improved treatment, some patients remain unresponsive. We propose an alternative approach to eliminate eosinophils using T cells by engineering IL-5Rα × CD3 bispecific T-cell engagers (bsTCEs) that target both IL-5Rα on eosinophils and CD3 on T cells. We designed different formats of IL-5Rα × CD3 bsTCEs, incorporating variations in valency, geometry, and affinity for the target antigen binding. We identified the single-chain variable fragment (scFv)-Fc format with the highest affinity toward the membrane-proximal domain of IL-5Rα in the IL-5Rα-binding arm showed the most potent cytotoxicity against IL-5Rα-expressing peripheral eosinophils by activating autologous primary T cells from healthy donors. This study proposes IL-5Rα × CD3 bsTCEs as potential alternatives for SEA treatment. Importantly, it demonstrates the first application of bsTCEs in eliminating disease-associated cells, including eosinophils, beyond cancer cells.

The emerging spectrum of fetal acetylcholine receptor antibody-related disorders (FARAD).

In utero exposure to maternal antibodies targeting the fetal acetylcholine receptor isoform (fAChR) can impair fetal movement, leading to arthrogryposis multiplex congenita (AMC). Fetal AChR antibodies have also been implicated in apparently rare, milder myopathic presentations termed fetal acetylcholine receptor inactivation syndrome (FARIS). The full spectrum associated with fAChR antibodies is still poorly understood. Moreover, since some mothers have no myasthenic symptoms, the condition is likely underreported, resulting in failure to implement effective preventive strategies. Here we report clinical and immunological data from a multicentre cohort (n = 46 cases) associated with maternal fAChR antibodies, including 29 novel and 17 previously reported with novel follow-up data. Remarkably, in 50% of mothers there was no previously established myasthenia gravis (MG) diagnosis. All mothers (n = 30) had AChR antibodies and, when tested, binding to fAChR was often much greater than that to the adult AChR isoform. Offspring death occurred in 11/46 (23.9%) cases, mainly antenatally due to termination of pregnancy prompted by severe AMC (7/46, 15.2%), or during early infancy, mainly from respiratory failure (4/46, 8.7%). Weakness, contractures, bulbar and respiratory involvement were prominent early in life, but improved gradually over time. Facial (25/34; 73.5%) and variable peripheral weakness (14/32; 43.8%), velopharyngeal insufficiency (18/24; 75%) and feeding difficulties (16/36; 44.4%) were the most common sequelae in long-term survivors. Other unexpected features included hearing loss (12/32; 37.5%), diaphragmatic paresis (5/35; 14.3%), CNS involvement (7/40; 17.5%) and pyloric stenosis (3/37; 8.1%). Oral salbutamol used empirically in 16/37 (43.2%) offspring resulted in symptom improvement in 13/16 (81.3%). Combining our series with all previously published cases, we identified 21/85 mothers treated with variable combinations of immunotherapies (corticosteroids/intravenous immunoglobulin/plasmapheresis) during pregnancy either for maternal MG symptom control (12/21 cases) or for fetal protection (9/21 cases). Compared to untreated pregnancies (64/85), maternal treatment resulted in a significant reduction in offspring deaths (P < 0.05) and other complications, with treatment approaches involving intravenous immunoglobulin/ plasmapheresis administered early in pregnancy most effective. We conclude that presentations due to in utero exposure to maternal (fetal) AChR antibodies are more common than currently recognized and may mimic a wide range of neuromuscular disorders. Considering the wide clinical spectrum and likely diversity of underlying mechanisms, we propose 'fetal acetylcholine receptor antibody-related disorders' (FARAD) as the most accurate term for these presentations. FARAD is vitally important to recognize, to institute appropriate management strategies for affected offspring and to improve outcomes in future pregnancies. Oral salbutamol is a symptomatic treatment option in survivors.

Preclinical Evaluation of interferon-gamma primed human Wharton's jelly-derived mesenchymal stem cells.

The potential of human mesenchymal stem cells (MSCs) for cell therapy has been investigated in numerous immune-mediated conditions; MSCs are considered one of the most promising cellular therapeutics to treat intractable diseases. Recently, approaches to prime MSCs have been investigated, thereby generating cellular products with enhanced potential for a variety of clinical applications. Interferon-gamma (IFN-γ) priming is a current approach used to increase the therapeutic efficacy of MSCs. In this study, we determined the systemic toxicity, tumorigenicity and biodistribution of IFN-γ-primed Wharton's jelly-derived (WJ)-MSCs in male and female BALB/c-nu/nu mice. There were no deaths or pathologic lesions in the mice treated with 5 × 106 cells/kg IFN-γ-primed MSCs in the repeated dose study. In the tumorigenicity study, one of the subcutaneously treated mice showed bronchioloalveolar adenoma in the lung but tested negative for human-specific anti-mitochondrial antibody, suggesting the spontaneous murine origin of the adenoma. A biodistribution study using real-time quantitative polymerase chain reaction demonstrated the systemic IFN-γ-primed MSC clearance by day 28. Based on the toxicity, biodistribution, and tumorigenicity studies, we concluded that IFN-γ-primed MSCs at 5 × 106 cells/kg do not induce tumor formation and adverse changes.

Clinical pitfalls and serological diagnostics of MuSK myasthenia gravis.

BACKGROUND: We aimed to evaluate the diagnostic accuracy of enzyme-linked immunosorbent assay (ELISA) for anti-muscle specific tyrosine kinase (MuSK) antibody (Ab) in a large cohort of anti-acetylcholine receptor (AChR) Ab-negative generalized myasthenia gravis (MG), and also to investigate clinical contexts for the diagnosis of MuSK MG. METHODS: A retrospective study of 160 patients with a clinical suspicion of AChR Ab-negative generalized MG was performed. The serum samples were tested for anti-clustered AChR Ab by cell-based assay (CBA), anti-MuSK Ab by ELISA, CBA and/or radioimmunoprecipitation assay (RIPA). Clinical data were compared between anti-MuSK Ab-positive MG and double seronegative (AChR and MuSK) MG groups. RESULTS: After excluding non-MG and clustered AChR Ab-positive patients, we identified 89 patients as a cohort of AChR Ab-negative generalized MG. Anti-MuSK Ab was positive by ELISA in 22 (24.7%) patients. While CBA identified five additional anti-MuSK Ab-positive patients, the results of ELISA were mostly consistent with CBA and RIPA with Cohen's kappa of 0.80 and 0.90, respectively (p < 0.001). The most frequent differential diagnosis was motor neuron disease particularly of bulbar onset which showed remarkably overlapping clinical and electrophysiological features with MuSK MG at presentation. CONCLUSION: While confirming the highest sensitivity of CBA for detecting anti-MuSK Ab, our results highlight the clinical pitfalls in making a diagnosis of MuSK MG and may support a diagnostic utility of MuSK-ELISA in clinical practice.

Expanding the Therapeutic Window of EGFR-Targeted PE24 Immunotoxin for EGFR-Overexpressing Cancers by Tailoring the EGFR Binding Affinity.

Immunotoxins (ITs), which are toxin-fused tumor antigen-specific antibody chimeric proteins, have been developed to selectively kill targeted cancer cells. The epidermal growth factor receptor (EGFR) is an attractive target for the development of anti-EGFR ITs against solid tumors due to its overexpression on the cell surface of various solid tumors. However, the low basal level expression of EGFR in normal tissue cells can cause undesirable on-target/off-tumor toxicity and reduce the therapeutic window of anti-EGFR ITs. Here, based on an anti-EGFR monobody with cross-reactivity to both human and murine EGFR, we developed a strategy to tailor the anti-EGFR affinity of the monobody-based ITs carrying a 24-kDa fragment of Pseudomonas exotoxin A (PE24), termed ER-PE24, to distinguish tumors that overexpress EGFR from normal tissues. Five variants of ER-PE24 were generated with different EGFR affinities (KD ≈ 0.24 nM to 104 nM), showing comparable binding activity for both human and murine EGFR. ER/0.2-PE24 with the highest affinity (KD ≈ 0.24 nM) exhibited a narrow therapeutic window of 19 pM to 93 pM, whereas ER/21-PE24 with an intermediate affinity (KD ≈ 21 nM) showed a much broader therapeutic window of 73 pM to 1.5 nM in in vitro cytotoxic assays using tumor model cell lines. In EGFR-overexpressing tumor xenograft mouse models, the maximum tolerated dose (MTD) of intravenous injection of ER/21-PE24 was found to be 0.4 mg/kg, which was fourfold higher than the MTD (0.1 mg/kg) of ER/0.2-PE24. Our study provides a strategy for the development of IT targeting tumor overexpressed antigens with basal expression in broad normal tissues by tailoring tumor antigen affinities.

A phase II, multicenter, open-label trial to evaluate the safety and efficacy of ISU303 (Agalsidase beta) in patients with Fabry disease.

BACKGROUND: Fabry disease (FD) is caused by a deficiency in the activity of the lysosomal enzyme, α-galactosidase A (α-Gal A), which leads to globotriaosylceramide (Gb3) deposition in multiple tissues. The current management of FD is enzyme replacement therapy (ERT). We report on the efficacy and safety of a new agalsidase beta, ISU303, in FD. METHODS: Ten patients (7 males, 3 females) were enrolled and administered a 1 mg/kg dose of ISU303, every other week for 6 months. The primary endpoint was the normalization of plasma Gb3 level. The secondary endpoints were the changes from baseline in urine Gb3 and the plasma and urine lyso-globotriaosylsphingosine (lyso-Gb3) level. Echocardiography, renal function test, and pain-related quality of life were also assessed before and after administration. Safety evaluation was performed including vital signs, laboratory tests, electrocardiograms, antibody screening tests, and adverse events at each visit. RESULTS: At 22 weeks of treatment, plasma and urine Gb3 level decreased by a mean of 4.01 ±â€…1.29 µg/mL (range 2.50-5.70) (P = .005) and 1.12 ±â€…1.98 µg/mg Cr. (range 0.04-5.65) (P = .017), respectively. However, no significant difference was observed in plasma and urine lyso-Gb3 levels. Echocardiography also was not changed. Renal function and pain-related quality of life showed improvements, but there was no clinical significance. No severe adverse events were observed. Only 1 patient developed an anti-drug antibody without neutralizing activity during the trial. CONCLUSION: This study showed the efficacy and safety of ISU303. Treatment with ISU303 significantly resulted in plasma and urine Gb3 decrease in patients with FD. These results suggest that ISU303 is safe and effective and can alternative ERT for FD.

Dual role of ERK2/NF-κB signaling in TRAIL sensitivity.

Targeting tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling is a promising approach in cancer treatment. Although ERK and/or NF-κB signaling is involved in the expression of TRAIL receptors (TRAIL-R), the exact underlying mechanisms remain unknown. In this study, we evaluated the role of ERK2 and NF-κB in the cytotoxicity of TRAIL during cisplatin treatment. Cisplatin treatment of neuroepithelioma cells (SK-N-MC) significantly induced ERK2 activation and increased TRAIL cytotoxicity via the upregulation of death receptor 5 (DR5) expression. In partial ERK2 knockdown cell lines that maintained only basal levels of ERK2 activity, cisplatin treatment did not increase ERK2 activity or DR5 expression. These findings indicate that induced (rather than basal) ERK2 activity enhances TRAIL susceptibility via DR5 expression. In complete ERK2 knockdown cell lines with no basal ERK2 activity, DR4, DR5, and DcRs expression levels were increased, and additional treatment with cisplatin did not further increase TRAIL-R expression. Chemical inhibition of ERK2 also enhanced TRAIL cytotoxicity by upregulating DR4 and DR5 expression. These findings indicate that basal ERK2 activity suppresses TRAIL-R expression. Both basal and inducible ERK2 activities regulate TRAIL-R expression via the NF-κB signaling pathway. Overall, our findings suggest that the ERK2/NF-κB signaling pathway has a dual role in TRAIL susceptibility by differentially regulating TRAIL-R expression in the same cellular system.

Nogo-A Is Critical for Pro-Inflammatory Gene Regulation in Myocytes and Macrophages.

Nogo-A (Rtn 4A), a member of the reticulon 4 (Rtn4) protein family, is a neurite outgrowth inhibitor protein that is primarily expressed in the central nervous system (CNS). However, previous studies revealed that Nogo-A was upregulated in skeletal muscles of Amyotrophic lateral sclerosis (ALS) patients. Additionally, experiments showed that endoplasmic reticulum (ER) stress marker, C/EBP homologous protein (CHOP), was upregulated in gastrocnemius muscle of a murine model of ALS. We therefore hypothesized that Nogo-A might relate to skeletal muscle diseases. According to our knocking down and overexpression results in muscle cell line (C2C12), we have found that upregulation of Nogo-A resulted in upregulation of CHOP, pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, while downregulation of Nogo-A led to downregulation of CHOP, IL-6 and TNF-α. Immunofluorescence results showed that Nogo-A and CHOP were expressed by myofibers as well as tissue macrophages. Since resident macrophages share similar functions as bone marrow-derived macrophages (BMDM), we therefore, isolated macrophages from bone marrow to study the role of Nogo-A in activation of these cells. Lipopolysaccharide (LPS)-stimulated BMDM in Nogo-KO mice showed low mRNA expression of CHOP, IL-6 and TNF-α compared to BMDM in wild type (WT) mice. Interestingly, Nogo knockout (KO) BMDM exhibited lower migratory activity and phagocytic ability compared with WT BMDM after LPS treatment. In addition, mice experiments data revealed that upregulation of Nogo-A in notexin- and tunicamycin-treated muscles was associated with upregulation of CHOP, IL-6 and TNF-α in WT group, while in Nogo-KO group resulted in low expression level of CHOP, IL-6 and TNF-α. Furthermore, upregulation of Nogo-A in dystrophin-deficient (mdx) murine model, myopathy and Duchenne muscle dystrophy (DMD) clinical biopsies was associated with upregulation of CHOP, IL-6 and TNF-α. To the best of our knowledge, this is the first study to demonstrate Nogo-A as a regulator of inflammation in diseased muscle and bone marrow macrophages and that deletion of Nogo-A alleviates muscle inflammation and it can be utilized as a therapeutic target for improving muscle diseases.

Mesenchymal stem cells in suppression or progression of hematologic malignancy: current status and challenges.

Mesenchymal stem cells (MSCs) are known for being multi-potent. However, they also possess anticancer properties, which has prompted efforts to adapt MSCs for anticancer therapies. However, MSCs have also been widely implicated in pathways that contribute to tumor growth. Numerous studies have been conducted to adapt MSCs for further clinical use; however, the results have been inconclusive, possibly due to the heterogeneity of MSC populations. Moreover, the conflicting roles of MSCs in tumor inhibition and tumor growth impede their adaptation for anticancer therapies. Antitumorigenic and protumorigenic properties of MSCs in hematologic malignancies are not as well established as they are for solid malignancies, and data comparing them are still limited. Herein the effect of MSCs on hematologic malignancies, such as leukemia and lymphoma, their mechanisms, sources of MSCs, and their effects on different types of cancer, have been discussed. This review describes how MSCs preserve both antitumorigenic and protumorigenic effects, as they tend to not only inhibit tumor growth by suppressing tumor cell proliferation but also promote tumor growth by suppressing tumor cell apoptosis. Thus clinical studies trying to adapt MSCs for anticancer therapies should consider that MSCs could actually promote hematologic cancer progression. It is necessary to take extreme care while developing MSC-based cell therapies in order to boost anticancer properties while eliminating tumor-favoring effects. This review emphasizes that research on the therapeutic applications of MSCs must consider that they exert both antitumorigenic and protumorigenic effects on hematologic malignancies.

Inhibition of N-myc expression sensitizes human neuroblastoma IMR-32 cells expressing caspase-8 to TRAIL.

OBJECTIVES: This study aims to explore the roles of N-myc and caspase-8 in TRAIL-resistant IMR-32 cells which exhibit MYCN oncogene amplification and lack caspase-8 expression. MATERIALS AND METHODS: We established N-myc-downregulated IMR-32 cells using shRNA lentiviral particles targeting N-myc and examined the effect the N-myc inhibition on TRAIL susceptibility in human neuroblastoma IMR-32 cells expressing caspase-8. RESULTS: Cisplatin treatment in IMR-32 cells increased the expression of death receptor 5 (DR5; TRAIL-R2), but not other receptors, via downregulation of NF-κB activity. However, the cisplatin-mediated increase in DR5 failed to induce cell death following TRAIL treatment. Furthermore, interferon (IFN)-γ pretreatment increased caspase-8 expression in IMR-32 cells, but cisplatin failed to trigger TRAIL cytotoxicity. We downregulated N-myc expression in IMR-32 cells using N-myc-targeting shRNA. These cells showed decreased growth rate and Bcl-2 expression accompanied by a mild collapse in the mitochondrial membrane potential as compared with those treated with scrambled shRNA. TRAIL treatment in N-myc-negative cells expressing caspase-8 following IFN-γ treatment significantly triggered apoptotic cell death. Concurrent treatment with cisplatin enhanced TRAIL-mediated cytotoxicity, which was abrogated by an additional pretreatment with DR5:Fc chimera protein. CONCLUSIONS: N-myc and caspase-8 expressions are involved in TRAIL susceptibility in IMR-32 cells, and the combination of treatment with cisplatin and TRAIL may serve as a promising strategy for the development of therapeutics against neuroblastoma that is controlled by N-myc and caspase-8 expression.

Characteristics of South Korean Patients with Hereditary Transthyretin Amyloidosis.

BACKGROUND AND PURPOSE: This retrospective cross-sectional study included 18 patients from unrelated families harboring mutations of the transthyretin gene (TTR), and analyzed their characteristics and geographical distribution in South Korea. METHODS: The included patients had a diagnosis of systemic amyloidosis, clinical symptoms, such as amyloid neuropathy or cardiomyopathy, and confirmation of a TTR gene mutation using genetic analysis recorded between April 1995 and November 2014. RESULTS: The mean age at disease onset was 49.6 years, and the mean disease duration from symptom onset to diagnosis was 3.67 years. Fifteen of the 18 patients were classified as mixed phenotype, 2 as the neurological phenotype, and only 1 patient as the cardiac phenotype. The most-common mutation pattern in South Korea was Asp38Ala, which was detected in eight patients. Thirteen patients reported their family hometowns, and five of the eight harboring the Asp38Ala mutation were from the Gyeongsang province in southeast Korea. The other eight patients exhibited a widespread geographical distribution. A particularly noteworthy finding was that the valine at position 30 (Val30Met) mutation, which was previously reported as the most-common TTR mutation worldwide and also the most common in the Japanese population, was not detected in the present South Korean patients. CONCLUSIONS: South Korean patients with hereditary TTR amyloidosis exhibited heterogeneous TTR genotypes and clinical phenotypes. The findings of this study suggest that the distribution of TTR amyloidosis in South Korea is due to de novo mutations and/or related to the other countries in East Asia.

Human Adipose Tissue Stem Cells Promote the Growth of Acute Lymphoblastic Leukemia Cells in NOD/SCID Mice.

In this study, the effect of adipose tissue stem cells (ASCs) on the growth of acute lymphoblastic leukemia (ALL) cells was examined in an in vivo model. We established ALL cell lines expressing firefly luciferase (ALL/fLuc) by lentiviral infection that were injected intraperitoneally to NOD/SCID mice. The luciferase activities were significantly higher in mice co-injected with 105 ALL/fLuc cells and ASCs than in those injected with ALL/fLuc cells alone. Co-injection of 105 ALL/fLuc cells and ASCs in differing ratios into mice gradually increased the bioluminescence intensity in all groups, and mice co-injected with 1 or 2 × 106 ASCs showed higher bioluminescence intensity than those receiving lower numbers. Interestingly, in the mice injected with 105 or 107 ALL/fLuc cells alone, the formation of tumor masses was not observed for at least five weeks. Moreover, co-injection of 107 ALL/fLuc cells and 5 × 105 ASCs into mice increased the bioluminescence intensity in all groups, and showed significantly higher bioluminescence intensity compared to mice co-injected with human normal fibroblast HS68 cells. Overall, ASCs promote the growth of ALL cells in vivo, suggesting that ASCs negatively influence hematologic malignancy, which should be considered in developing cell therapy using ASCs.

Myasthenia gravis seronegative for acetylcholine receptor antibodies in South Korea: Autoantibody profiles and clinical features.

Acquired myasthenia gravis (MG) is a prototype autoimmune disease of the neuromuscular junction, caused in most patients by autoantibodies to the muscle nicotinic acetylcholine receptor (AChR). There seem to be ethnic and regional differences in the frequency and clinical features of MG seronegative for the AChR antibody. This study aimed to describe the autoantibody profiles and clinical features of Korean patients with generalized MG seronegative for the AChR antibody. A total of 62 patients with a high index of clinical suspicion of seronegative generalized MG were identified from 18 centers, and we examined their sera for antibodies to clustered AChR, muscle-specific tyrosine kinase (MuSK), and low-density lipoprotein receptor-related protein 4 (LRP4) by cell-based assays (CBA) and to MuSK by radioimmunoprecipitation assay (RIPA). We also included 8 patients with ocular MG, 3 with Lambert-Eaton myasthenic syndrome, 5 with motor neuron disease, and 9 with other diagnoses as comparators for the serological testing. Antibodies were identified in 25/62 (40.3%) patients: 7 had antibodies to clustered AChR, 17 to MuSK, and 2 to LRP4. Three patients were double seropositive: 1 for MuSK and LRP4, and 2 for MuSK and clustered AChR. The patients with MuSK antibodies were mostly female (88.2%) and characterized by predominantly bulbar involvement (70%) and frequent myasthenic crises (58.3%). The patients with antibodies to clustered AChR, including 2 with ocular MG, tended to have a mild phenotype and good prognosis.

Anti-leukemic effects of PPARγ ligands.

The peroxisome proliferator-activated receptor (PPAR) γ, a subtype of PPARs, is a member of the nuclear receptor family. PPARγ and its ligands contribute to various types of diseases including cancer. Given that currently developed therapies against leukemia are not very effective or safe, PPARγ ligands have been shown to be a new class of compounds with the potential to treat hematologic malignancies, particularly leukemia. The capability of PPARγ ligands to induce apoptosis, inhibit proliferation, and promote differentiation of leukemia cells suggests it has significant potential as a drug against leukemia. However, the specific mechanisms and molecules involved are not well-understood, although a number of PPARγ ligands with anti-leukemic effects have been identified. This may explain why PPARγ ligands have not been widely evaluated in clinical trials. To fill the gaps in the lack of understanding of specific anti-leukemic processes of PPARγ ligands and further adapt these molecules as anti-leukemic agents, this review describes previous studies of the anti-leukemic effects of PPARγ ligands.

Enhanced Immunosuppressive Properties of Human Mesenchymal Stem Cells Primed by Interferon-γ.

Mesenchymal stem cells (MSCs) are of particular interest for the treatment of immune-related diseases owing to their immunosuppressive properties. In this study, we aimed to identify the effect of interferon (IFN)-γ priming on immunomodulation by MSCs and elucidate the possible mechanism underlying their properties for the clinical treatment of allogeneic conflicts. Infusion of MSCs primed with IFN-γ significantly reduced the symptoms of graft-versus-host disease (GVHD) in NOD-SCID mice, thereby increasing survival rate when compared with naïve MSC-infused mice. However, infusion of IFN-γ-primed MSCs in which indoleamine 2,3-dioxygenase (IDO) was downregulated did not elicit this effect. The IDO gene was expressed in MSCs via the IFN-γ-Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1) pathway, and the infusion of IDO-over-expressing MSCs increased survival rate in an in vivo GVHD model, similar to infusion of IFN-γ-primed MSCs. These data indicate that IFN-γ production by activated T-cells is correlated with the induction of IDO expression in MSCs via the IFN-γ-JAK-STAT1 pathway, which in turn results in the suppression of T-cell proliferation. Our findings also suggest that cell therapy based on MSCs primed with IFN-γ can be used for the clinical treatment of allogeneic conflicts, including GVHD.

Involvement of TLR3-Dependent PGES Expression in Immunosuppression by Human Bone Marrow Mesenchymal Stem Cells.

Human mesenchymal stem cells (MSCs) are known for their prostaglandin E2 (PGE2)-mediated immunosuppressive function but the precise molecular mechanisms underlying PGE2 biosynthesis during inflammation have not been completely elucidated. In this study, we have investigated the involvement of PGE2 pathway members in PGE2 production by bone marrow (BM)-MSCs in response to inflammatory stimuli, and their role in immunosuppression mediated by BM-MSCs. We found that IFN-γ and TNF-α increased cyclooxygenase (COX)-2 expression but not that of prostaglandin E synthase (PGES), or PGE2 production. On the other hand, the toll like receptor 3 (TLR3) stimulant poly(I:C) increased expression of both COX-2 and PGES, resulting in a significant increase in PGE2 levels. This effect was reversed upon COX-2 inhibition with indomethacin or PGES downregulation by siRNA. Reduced PGE2 levels decreased MSC's capacity to inhibit hPBMC proliferation. In addition, administration of MSCs with inhibited PGES expression into mice with graft-versus-host disease (GVHD) did not reduce mortality. In summary, the present study reveals that upregulation of PGES via TLR3 is critical for BM-MSCs-mediated immunosuppression by PGE2 secretion via the COX-2/PGE2 pathway. These results provide a basis for understanding the molecular mechanisms underlying the PGE2-mediated immunosuppressive properties of MSCs.

Clinical characteristics and mutation spectrum of GLA in Korean patients with Fabry disease by a nationwide survey: Underdiagnosis of late-onset phenotype.

Fabry disease is a rare X-linked lysosomal storage disorder caused by an α-galactosidase A deficiency. The progressive accumulation of globotriaosylceramide (GL-3) results in life-threatening complications, including renal, cardiac, and cerebrovascular diseases. This study investigated the phenotypic and molecular spectra of GLA mutations in Korean patients with Fabry disease using a nationwide survey.This study included 94 patients from 46 independent pedigrees: 38 adult males, 46 symptomatic females, and 10 pediatric males. Each diagnosis was based on an enzyme assay and GLA gene mutation analysis.The mean age at presentation was 24 years (range, 5-65 years); however, the diagnoses were delayed by 21 ±â€Š19 years after the onset of symptoms. Those patients with late-onset Fabry disease were diagnosed by family screening or milder symptoms at a later age. Forty different mutations were identified: 20 missense (50%), 10 nonsense (25%), 8 frameshift (20%), and 2 splice site (5%) mutations. Five of them were novel. IVS4+919G>A (c.936+919 G>A) was not detected among the 6505 alleles via newborn screening using dried blood spots. Enzyme replacement therapy (ERT) was performed in all the males and pediatric patients, whereas 75% of the symptomatic females underwent ERT for 4.2 ±â€Š3.6 years.This study described the demographic data, wide clinical spectrum of phenotypes, and GLA mutation spectrum of Fabry disease in Korea. Most of the patients had classical Fabry disease, with a 4 times higher incidence than that of late-onset Fabry disease, indicating an underdiagnosis of mild, late-onset Fabry disease.

Cell culture density affects the stemness gene expression of adipose tissue-derived mesenchymal stem cells.

The results of clinical trials using mesenchymal stem cells (MSCs) are controversial due to the heterogeneity of human MSCs and differences in culture conditions. In this regard, it is important to identify gene expression patterns according to culture conditions, and to determine how the cells are expanded and when they should be clinically used. In the current study, stemness gene expression was investigated in adipose tissue-derived MSCs (AT-MSCs) harvested following culture at different densities. AT-MSCs were plated at a density of 200 or 5,000 cells/cm2. After 7 days of culture, stemness gene expression was examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. The proliferation rate of AT-MSCs harvested at a low density (~50% confluent) was higher than that of AT-MSCs harvested at a high density (~90% confluent). Although there were differences in the expression levels of stemness gene, such as octamer-binding transcription factor 4, nanog homeobox (Nanog), SRY-box 2, Kruppel like factor 4, v-myc avian myelocytomatosis viral oncogene homolog (c-Myc), and lin-28 homolog A, in the AT-MSCs obtained from different donors, RT-qPCR analysis demonstrated differential gene expression patterns according to the cell culture density. Expression levels of stemness genes, particularly Nanog and c-Myc, were upregulated in AT-MSCs harvested at a low density (~50% confluent) in comparison to AT-MSCs from the same donor harvested at a high density (~90% confluent). These results imply that culture conditions, such as the cell density at harvesting, modulate the stemness gene expression and proliferation of MSCs.

Inhibition of ERK activity enhances the cytotoxic effect of peroxisome proliferator-activated receptor γ (PPARγ) agonists in HeLa cells.

In this study, we examined whether the peroxisome proliferator-activated receptor γ (PPARγ) agonists, ciglitazone (CGZ) and troglitazone (TGZ), induce cell death in human cervical cancer HeLa cells. The cells were treated with a range of CGZ or TGZ doses for 24 or 48 h. Low concentrations of CGZ (≤10 µM) or TGZ (≤20 µM) had no effect on cell viability whereas higher doses induced cell death in a time- and dose-dependent manner as evidenced by the detection of activated caspase-3 and PARP cleavage. Treatment with the PPARγ antagonist GW9662 followed by PPARγ agonists did not increase CGZ- or TGZ-induced cell death, indicating that PPARγ agonists induced HeLa cell death independently of PPARγ. Moreover, ERK1/2 activation was observed at a CGZ concentration of 25 µM and a TGZ concentration of 35 µM, both of which induced cell death. To elucidate the role of ERK1/2 activated by the two PPARγ agonists, the effect of U0126, an inhibitor of ERK1/2, on PPARγ-agonist-induced cell death was examined. Treatment with 10 or 20 µM U0126 followed by CGZ or TGZ induced the down-regulation of ERK1/2 activity and a decrease in Bcl-2 expression accompanied by the collapse of mitochondrial membrane potential, which in turn significantly enhanced CGZ- or TGZ-induced apoptotic cell death. Our results suggest that PPARγ agonists are capable of inducing apoptotic cell death in HeLa cells independently of PPARγ and that inhibition of ERK1/2 activity offers a strategy to enhance the cytotoxicity of PPARγ agonists in the treatment of cervical cancer.

Application of human mesenchymal stem cells cultured in different oxygen concentrations for treatment of graft-versus-host disease in mice.

Human mesenchymal stem cell (MSC) heterogeneity and problems associated with the ex vivo expansion of MSC are linked with the failure of MSC clinical trials. In this study, we compared the effect of MSCs cultured in different oxygen concentrations on GVHD in mice to elucidate whether hypoxia improves the immunosuppressive capacity of MSCs. Hypoxia increased the proliferative activity and the expression of several stemness and chemokine genes, such as KLF4, OCT4, C-MYC, CCL2, and CXCL10. Mice that received MSCs cultured in normoxia or hypoxia showed alleviated symptoms of GVHD and increased survival times. However, there was no significant difference in survival rates between mice that received MSCs cultured in normoxia and hypoxia. These data suggest that hypoxic culture is a useful method for maintaining and obtaining MSCs used for cell therapy and that the therapeutic potential of MSCs cultured in hypoxia warrants further investigation.