Small molecule TCS21311 can replace BMP7 and facilitate cell proliferation in in vitro expansion culture of nephron progenitor cells.

Several groups have developed in vitro expansion cultures for mouse metanephric nephron progenitor cells (NPCs) using cocktails of small molecules and growth factors including BMP7. However, the detailed mechanisms by which BMP7 acts in the NPC expansion remain to be elucidated. Here, by performing chemical screening for BMP substitutes, we identified a small molecule, TCS21311, that can replace BMP7 and revealed a novel inhibitory role of BMP7 in JAK3-STAT3 signaling in NPC expansion culture. Further, we found that TCS21311 facilitates the proliferation of mouse embryonic NPCs and human induced pluripotent stem cell-derived NPCs when added to the expansion culture. These results will contribute to understanding the mechanisms of action of BMP7 in NPC proliferation in vitro and in vivo and to the stable supply of NPCs for regenerative therapy, disease modeling and drug discovery for kidney diseases.

Pluripotent stem cell models of Blau syndrome reveal an IFN-γ-dependent inflammatory response in macrophages.

BACKGROUND: Blau syndrome, or early-onset sarcoidosis, is a juvenile-onset systemic granulomatosis associated with a mutation in nucleotide-binding oligomerization domain 2 (NOD2). The underlying mechanisms of Blau syndrome leading to autoinflammation are still unclear, and there is currently no effective specific treatment for Blau syndrome. OBJECTIVES: To elucidate the mechanisms of autoinflammation in patients with Blau syndrome, we sought to clarify the relation between disease-associated mutant NOD2 and the inflammatory response in human samples. METHODS: Blau syndrome-specific induced pluripotent stem cell (iPSC) lines were established. The disease-associated NOD2 mutation of iPSCs was corrected by using a CRISPR-Cas9 system to precisely evaluate the in vitro phenotype of iPSC-derived cells. We also introduced the same NOD2 mutation into a control iPSC line. These isogenic iPSCs were then differentiated into monocytic cell lineages, and the statuses of nuclear factor κB pathway and proinflammatory cytokine secretion were investigated. RESULTS: IFN-γ acted as a priming signal through upregulation of NOD2. In iPSC-derived macrophages with mutant NOD2, IFN-γ treatment induced ligand-independent nuclear factor κB activation and proinflammatory cytokine production. RNA sequencing analysis revealed distinct transcriptional profiles of mutant macrophages both before and after IFN-γ treatment. Patient-derived macrophages demonstrated a similar IFN-γ-dependent inflammatory response. CONCLUSIONS: Our data support the significance of ligand-independent autoinflammation in the pathophysiology of Blau syndrome. Our comprehensive isogenic disease-specific iPSC panel provides a useful platform for probing therapeutic and diagnostic clues for the treatment of patients with Blau syndrome.

High event-free survival rate with minimum-dose-anthracycline treatment in childhood acute promyelocytic leukaemia: a nationwide prospective study by the Japanese Paediatric Leukaemia/Lymphoma Study Group.

We evaluated the efficacy of treatment using reduced cumulative doses of anthracyclines in children with acute promyelocytic leukaemia (APL) in the Japanese Paediatric Leukaemia/Lymphoma Study Group AML-P05 study. All patients received two and three subsequent courses of induction and consolidation chemotherapy respectively, consisting of all-trans retinoic acid (ATRA), cytarabine and anthracyclines, followed by maintenance therapy with ATRA. Notably, a single administration of anthracyclines was introduced in the second induction and all consolidation therapies to minimize total doses of anthracycline. The 3-year event-free (EFS) and overall survival rates for 43 eligible children were 83·6% [95% confidence interval (CI): 68·6-91·8%] and 90·7% (95% CI: 77·1-96·4%), respectively. Although two patients died of intracranial haemorrhage or infection during induction phases, no cardiac adverse events or treatment-related deaths were observed during subsequent phases. Patients not displaying M1 marrow after the first induction therapy, or those under 5 years of age at diagnosis, showed inferior outcomes (3-year EFS rate; 33·3% (95% CI: 19·3-67·6%) and 54·6% (95% CI: 22·9-78·0%), respectively). In conclusion, a single administration of anthracycline during each consolidation phase was sufficient for treating childhood APL. In younger children, however, conventional ATRA and chemotherapy may be insufficient so that alternative therapies should be considered.

Response to comment on "Drug screening for ALS using patient-specific induced pluripotent stem cells".

Our work and the study of Bilican et al. highlight the need for complementary assays to detect subtle phenotypic differences between control and mutant induced pluripotent stem cell lines.

Drug screening for ALS using patient-specific induced pluripotent stem cells.

Amyotrophic lateral sclerosis (ALS) is a late-onset, fatal disorder in which the motor neurons degenerate. The discovery of new drugs for treating ALS has been hampered by a lack of access to motor neurons from ALS patients and appropriate disease models. We generate motor neurons from induced pluripotent stem cells (iPSCs) from familial ALS patients, who carry mutations in Tar DNA binding protein-43 (TDP-43). ALS patient-specific iPSC-derived motor neurons formed cytosolic aggregates similar to those seen in postmortem tissue from ALS patients and exhibited shorter neurites as seen in a zebrafish model of ALS. The ALS motor neurons were characterized by increased mutant TDP-43 protein in a detergent-insoluble form bound to a spliceosomal factor SNRPB2. Expression array analyses detected small increases in the expression of genes involved in RNA metabolism and decreases in the expression of genes encoding cytoskeletal proteins. We examined four chemical compounds and found that a histone acetyltransferase inhibitor called anacardic acid rescued the abnormal ALS motor neuron phenotype. These findings suggest that motor neurons generated from ALS patient-derived iPSCs may provide a useful tool for elucidating ALS disease pathogenesis and for screening drug candidates.

Anti-Aß drug screening platform using human iPS cell-derived neurons for the treatment of Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder that causes progressive memory and cognitive decline during middle to late adult life. The AD brain is characterized by deposition of amyloid ß peptide (Aß), which is produced from amyloid precursor protein by ß- and γ-secretase (presenilin complex)-mediated sequential cleavage. Induced pluripotent stem (iPS) cells potentially provide an opportunity to generate a human cell-based model of AD that would be crucial for drug discovery as well as for investigating mechanisms of the disease. METHODOLOGY/PRINCIPAL FINDINGS: We differentiated human iPS (hiPS) cells into neuronal cells expressing the forebrain marker, Foxg1, and the neocortical markers, Cux1, Satb2, Ctip2, and Tbr1. The iPS cell-derived neuronal cells also expressed amyloid precursor protein, ß-secretase, and γ-secretase components, and were capable of secreting Aß into the conditioned media. Aß production was inhibited by ß-secretase inhibitor, γ-secretase inhibitor (GSI), and an NSAID; however, there were different susceptibilities to all three drugs between early and late differentiation stages. At the early differentiation stage, GSI treatment caused a fast increase at lower dose (Aß surge) and drastic decline of Aß production. CONCLUSIONS/SIGNIFICANCE: These results indicate that the hiPS cell-derived neuronal cells express functional ß- and γ-secretases involved in Aß production; however, anti-Aß drug screening using these hiPS cell-derived neuronal cells requires sufficient neuronal differentiation.

The effects of cardioactive drugs on cardiomyocytes derived from human induced pluripotent stem cells.

Developing effective drug therapies for arrhythmic diseases is hampered by the fact that the same drug can work well in some individuals but not in others. Human induced pluripotent stem (iPS) cells have been vetted as useful tools for drug screening. However, cardioactive drugs have not been shown to have the same effects on iPS cell-derived human cardiomyocytes as on embryonic stem (ES) cell-derived cardiomyocytes or human cardiomyocytes in a clinical setting. Here we show that current cardioactive drugs affect the beating frequency and contractility of iPS cell-derived cardiomyocytes in much the same way as they do ES cell-derived cardiomyocytes, and the results were compatible with empirical results in the clinic. Thus, human iPS cells could become an attractive tool to investigate the effects of cardioactive drugs at the individual level and to screen for individually tailored drugs against cardiac arrhythmic diseases.

Prospective multicenter trial comparing repeated immunosuppressive therapy with stem-cell transplantation from an alternative donor as second-line treatment for children with severe and very severe aplastic anemia.

We conducted a prospective multicenter study to compare the efficacy of repeated immunosuppressive therapy (IST) with stem-cell transplantation (SCT) from an alternative donor in children with acquired aplastic anemia (AA) who failed to respond to an initial course of IST. Patients with severe (n = 86) and very severe disease (n = 119) received initial IST consisting of antithymocyte globulin (ATG) and cyclosporine. Sixty patients failed to respond to IST after 6 months from the initial IST and were eligible for second-line treatment. Among them, 21 patients lacking suitable donors received a second course of IST. Three patients developed an anaphylactoid reaction to ATG and could not complete the second IST. A trilineage response was seen in only 2 of 18 (11%) evaluable patients after 6 months. Thirty-one patients received SCT from an alternative donor. At 5 years from the initiation of second-line therapy, the estimated failure-free survival (FFS), defined as survival with response, was 83.9% (+/- 16.1%, SD) in the SCT group compared with 9.5% (+/- 9.0%) in the IST group (P = .001). These results suggest that SCT from an alternative donor offers a better chance of FFS than a second IST in patients not responding to an initial IST.

Retrospective nationwide survey of Japanese patients with transfusion-dependent MDS and aplastic anemia highlights the negative impact of iron overload on morbidity/mortality.

OBJECTIVE: Myelodysplastic syndromes (MDS) and aplastic anemia (AA) are the most common anemias that require transfusion therapy in Japan. This retrospective survey investigated relationships between iron overload, chelation practices, and morbidity/mortality in patients with these diseases. METHOD: Medical histories of transfusion-dependent patients were assessed at transfusion onset, chelation onset, and study end. RESULTS: Data were collected from 292 patients with MDS, AA, pure red cell aplasia, myelofibrosis, and other conditions. Patients received a mean of 61.5 red blood cell units during the previous year. Fewer than half (43%) of patients had previously received deferoxamine (DFO) therapy. Only 8.6% received daily/continuous DFO. In all, 75 deaths were reported, with cardiac and liver failure noted in 24.0 and 6.7% of cases. Of these, 97% had ferritin levels >1000 ng/mL. Abnormal cardiac and liver function was observed in 21.9% (14/64) and 84.6% (11/13) of all patients assessed. Effective chelation with DFO resulted in improved serum ferritin, liver enzymes, and fasting blood sugar. CONCLUSIONS: Mortality is higher in heavily iron-overloaded patients, with liver and cardiac dysfunction being the primary cause. Daily/continuous chelation therapy was effective at reducing iron burden and improving organ function. Chelation therapy should be initiated once serum ferritin levels exceed 1000 ng/mL.

[Changes in Japanese cedar sensitization rates of Japanese allergic children during the last 15 years].

In order to evaluate the changes in Japanese Cedar (JC) sensitization rates of allergic children, serum samples from 88 patients about 15 years ago (past group) and those from 91 current patients (present group) were randomly selected, and their JC specific IgE were measured with the CAP-RAST system. Sensitivity rate (class 2 or more) for JC of the present group was 65.9%, which was significantly higher than that of the past group, which was 46.6%. However, there was no significant difference between these two groups for children aged 6 or younger. For children aged 7 or older, the sensitivity rate of the present group was significantly higher than that of the past group. Thus, protection against JC sensitization, especially during early childhood, should be given serious attention.

[Cedar pollinosis in Japanese schoolchildren: results from a large questionnaire-based survey].

PURPOSE: To evaluate the prevalence and clinical characteristics of Japanese cedar (Cryptomeria japonica) pollinosis (CP) in Japanese schoolchildren. METHODS: Questionnaire made by the Study Group of Epidemiology of Allergic Diseases founded by the Japanese Ministry of Public Health and Welfare was distributed to 56,108 schoolchildren living in the suburban areas of Kyoto, Japan. The data recovered from 50,086 children (recovery rate 89.3%) was analyzed. RESULTS AND DISCUSSION: Overall prevalence of CP was 5.2%. The prevalence was higher in older children, and in those born in autumn and winter. Prevalence of CP in southern urban area was significantly higher (p < 0.001) than that in northern rural area, suggesting that urban environment including air pollution might increase the prevalence of CP. Among children with AD, there was statistically significant correlation between the severity of AD and the presence of CP (p = 0.016), i.e. those with CP tended to have more severe AD symptoms. On the other hand, the severity of BA was not affected by the presence of CP (p = 0.323). These data suggest a contribution of cedar pollen to AD, but not to BA, symptoms. Overall, our present data shown that CP has become one of the important allergic diseases in childhood, and that further evaluation of CP among children would be necessary.