Mesenchymal cells regulate enteric neural crest cell migration via RET-GFRA1b trans-signaling.

During early development, the enteric nervous system forms from the migration of enteric neural crest cells (ENCCs) from the foregut to the hindgut, where they undergo proliferation and differentiation facilitated by interactions with enteric mesenchymal cells (EMCs). This study investigates the impact on ENCC migration of EMC-ENCC communication mediated by GFRA1b expressed in EMCs. GFRA1-expressing cells in day 11-12 (E11-12) mouse embryos differentiated into smooth muscle cells from E12 onwards. Observations at E12-13.5 revealed high levels of GFRA1 expression on the anti-mesenteric side of the hindgut, correlating with enhanced ENCC migration. This indicates that GFRA1 in EMCs plays a role in ENCC migration during development. Examining GFRA1 isoforms, we found high levels of GFRA1b, which lacks amino acids 140-144, in EMCs. To assess the impact of GFRA1 isoforms on EMC-ENCC communication, we conducted neurosphere drop assays. This revealed that GFRA1b-expressing cells promoted GDNF-dependent extension and increased neurite density in ENCC neurospheres. Co-culture of ENCC mimetic cells expressing RET and GFRA1a with EMC mimetic cells expressing GFRA1a, GFRA1b, or vector alone showed that only GFRA1b-expressing co-cultured cells sustained RET phosphorylation in ENCC-mimetic cells for over 120 min upon GDNF stimulation. Our study provides evidence that GFRA1b-mediated cell-to-cell communication plays a critical role in ENCC motility in enteric nervous system development. These findings contribute to understanding the cellular interactions and signaling mechanisms that underlie enteric nervous system formation and highlight potential therapeutic targets for gastrointestinal motility disorders.

Influence of Immune System Abnormalities Caused by Maternal Immune Activation in the Postnatal Period.

The developmental origins of health and disease (DOHaD) indicate that fetal tissues and organs in critical and sensitive periods of development are susceptible to structural and functional changes due to the adverse environment in utero. Maternal immune activation (MIA) is one of the phenomena in DOHaD. Exposure to maternal immune activation is a risk factor for neurodevelopmental disorders, psychosis, cardiovascular diseases, metabolic diseases, and human immune disorders. It has been associated with increased levels of proinflammatory cytokines transferred from mother to fetus in the prenatal period. Abnormal immunity induced by MIA includes immune overreaction or immune response failure in offspring. Immune overreaction is a hypersensitivity response of the immune system to pathogens or allergic factor. Immune response failure could not properly fight off various pathogens. The clinical features in offspring depend on the gestation period, inflammatory magnitude, inflammatory type of MIA in the prenatal period, and exposure to prenatal inflammatory stimulation, which might induce epigenetic modifications in the immune system. An analysis of epigenetic modifications caused by adverse intrauterine environments might allow clinicians to predict the onset of diseases and disorders before or after birth.

Tertiary hyperparathyroidism in patients with pseudohypoparathyroidism type 1a.

Pseudohypoparathyroidism type 1a (PHP1a) is a genetic disorder caused by heterozygous loss-of-function mutations on the maternal allele of the GNAS gene. Patients with PHP1a predominantly exhibit parathyroid hormone (PTH) resistance and physical features of Albright's hereditary osteodystrophy. We report two unrelated cases with PHP1a who developed tertiary hyperparathyroidism (HPT). Molecular analyses of the GNAS gene identified a previously known heterozygous 4-bp deletion (c. 565_568delGACT) in exon 7 in case 1 and a novel heterozygous missense mutation (p.Lys233Glu) in exon 9 in case 2. Both patients developed tertiary HPT associated with hyperfunctioning parathyroid glands during long-term treatment of hypocalcemia. Case 1 had severe osteoporosis and underwent parathyroidectomy. Case 2 was asymptomatic with no evidence of bone diseases associated with tertiary HPT. PHP1a patients are at risk of developing tertiary HPT and should be treated with sufficient doses of calcium and vitamin D to achieve serum PTH levels within the mid - normal to double the upper limit of the normal range, regardless of serum calcium levels.

Exposure to Maternal Immune Activation Causes Congenital Unfolded Protein Response Defects and Increases the Susceptibility to Postnatal Inflammatory Stimulation in Offspring.

BACKGROUND: A number of childhood diseases have been identified, such as severe infection or autoinflammatory disease, in which immune overreaction against inflammation is a possible underlying mechanism. Previous reports have demonstrated that fetal cells exposed to maternal immune activation (MIA) induced by polyriboinosinic-polyribocytidylic acid [poly(I:C)] exhibited hypersensitivity to inflammation in vitro. However, the details of this mechanism remain unclear. Therefore, this study aimed to reveal the reaction to inflammation in offspring exposed to MIA in the prenatal period, as well as its molecular mechanism, using a viral infection mouse model. MATERIALS AND METHODS: Pregnant mice at 12.5, 14.5, and 16.5 days post coitum were injected intraperitoneally with poly(I:C) 20 mg/kg body weight (BW) or saline. Offspring aged 3-4 weeks received the second injection of 20 mg/kg BW or 4 mg/kg BW poly(I:C) or saline. Serum and tissues were collected at 2, 24, 48, and 72 h after the postnatal injection. The cytokine profile, histopathology of organs, and unfolded protein response (UPR) in offspring were examined. RESULTS: The serum levels of interleukin (IL)-6, IL-17, and interferon-γ were significantly higher in the MIA group, and acute liver necrosis was detected. Moreover, failure in UPR was observed in the MIA group compared with that in the control group. CONCLUSION: Overall, MIA exposure in utero caused failure in UPR as well as immune overreaction to the second attack of inflammation in offspring. Our results suggested that prenatal exposure to MIA might contribute to the congenital inflammatory constitution after birth.

Interaction between the immune system and acute myeloid leukemia: A model incorporating promotion of regulatory T cell expansion by leukemic cells.

Population dynamics of regulatory T cells (Treg) are crucial for the underlying interplay between leukemic and immune cells in progression of acute myeloid leukemia (AML). The goal of this work is to elucidate the dynamics of a model that includes Treg, which can be qualitatively assessed by accumulating clinical findings on the impact of activated immune cell infusion after selective Treg depletion. We constructed an ordinary differential equation model to describe the dynamics of three components in AML: leukemic blast cells, mature regulatory T cells (Treg), and mature effective T cells (Teff), including cytotoxic T lymphocytes. The model includes promotion of Treg expansion by leukemic blast cells, leukemic stem cell and progenitor cell targeting by Teff, and Treg-mediated Teff suppression, and exhibits two coexisting, stable steady states, corresponding to high leukemic cell load at diagnosis or relapse, and to long-term complete remission. Our model is capable of explaining the clinical findings that the survival of patients with AML after allogeneic stem cell transplantation is influenced by the duration of complete remission, and that cut-off minimal residual disease thresholds associated with a 100% relapse rate are identified in AML.

Role of 18-fluoro-2-deoxyglucose positron emission tomography in detecting acute inflammatory lesions of non-bacterial osteitis in patients with a fever of unknown origin: A comparative study of 18-fluoro-2-deoxyglucose positron emission tomography, bone scan, and magnetic resonance imaging.

We report three patients with non-bacterial osteitis (NBO) who had fever of unknown origin (FUO) as an initial symptom. 18-Fluoro-2-deoxyglucose positron emission tomography (18F-FDG-PET) can be used to detect acute inflammatory lesions. There seems to be variation among the results of 18F-FDG-PET, a bone scan, and magnetic resonance imaging (MRI). Therefore, it would be useful to perform a bone scan to detect all lesions, combined with MRI to confirm the diagnosis of NBO, followed by 18F-FDG-PET.

Sinonasal NUT carcinoma: clinicopathological and cytogenetic analysis with autopsy findings.

Nuclear protein in testis (NUT) carcinoma is a rare malignant neoplasm with an undifferentiated morphology. Its diagnosis is often difficult, especially as the sinonasal tract gives rise to many tumors with undifferentiated morphologies. Not many cases of sinonasal NUT carcinomas have been reported, and its clinicopathological features have not been sufficiently clarified. In this study, we performed a clinicopathological study of 4 patients with sinonasal NUT carcinoma, including wide-ranging immunohistochemical tests and cytogenetic analyses using fluorescence in situ hybridization and DNA sequencing. Autopsy findings were obtained from 2 patients. Patients' ages ranged from 9 months to 66 years (median, 37 years). Three cases involved the nasal cavity; of these, 2 also involved the ethmoid sinus. One case only involved the frontal sinus. Histologically, all cases revealed undifferentiated small round cell morphology and necrosis with indistinct cell borders, vesicular chromatin, and distinct nucleoli. All patients received chemoradiotherapy; 3 died of disease 10 to 15 months after their diagnoses, while one was lost to follow-up. The 2 autopsied patients showed multiorgan metastases; interestingly, one showed cartilaginous differentiation in a metastatic lesion. Immunohistochemically, all cases were diffusely positive for NUT, p63, and Myc, and were focal for p40. The cells variably expressed epithelial markers, and CD34 was positive in one patient. Cytogenetically, all showed BRD4-NUT fusion genes, but one had a different breakpoint in each exon. Finally, a literature review indicated that sinonasal NUT carcinoma tends to involve frontal and ethmoidal sinuses more frequently than other sinonasal cancers.

Interleukin-18 for predicting the development of macrophage activation syndrome in systemic juvenile idiopathic arthritis.

To assess the role of IL-6/IL-18 in the pathogenesis of systemic juvenile idiopathic arthritis (s-JIA) and to investigate the clinical significance of serum IL-18 levels for predicting macrophage activation syndrome (MAS) development, we measured the serum IL-6/IL-18 levels in 76s-JIA patients, including 15 with MAS, and compared them with the clinical features. We identified 2 distinct subsets on the basis of serum IL-6/IL-18 levels. The IL-18-dominant subset had more patients who developed MAS. Serum IL-18 levels during active phase in patients with MAS were significantly higher than those without MAS. The cutoff value of serum IL-18 levels for predicting MAS development was 47750 pg/ml. The patients with IL-18 dominant subset at their disease onset were significantly more likely to develop MAS after TCZ therapy started. IL-18 might have a key role in the pathogenesis of MAS. Serum IL-18 levels >47750 pg/ml might be useful to predict MAS development.

Intermittent X-linked thrombocytopenia with a novel WAS gene mutation.

X-linked thrombocytopenia (XLT) is caused by mutations in the WAS gene and characterized by thrombocytopenia with minimal or no immunodeficiency. Patients with XLT usually exhibit persistent thrombocytopenia, and intermittent thrombocytopenia has been described only in two families. Here, we report a patient with intermittent XLT carrying a novel missense mutation (Ala56Thr). He showed residual expression of Wiskott-Aldrich syndrome protein in the lymphocytes and platelets. There appeared to be an association between normal platelet numbers and a post infectious state. Our findings further support the importance of analysis of Wiskott-Aldrich syndrome protein in male patients who exhibit fluctuating courses of thrombocytopenia.

Subclinical arterial stiffness in young children after Kawasaki disease.

BACKGROUND: Recent studies have revealed that atherosclerosis progresses faster than expected in young adults with a history of Kawasaki disease. However, it is unclear as to when these arterial changes become measurable. In this study, we evaluated subclinical arterial stiffness in young children with a history of Kawasaki disease using two-dimensional ultrasound speckle tracking. METHODS: A total of 75 children with a history of Kawasaki disease (mean age, 8.2 ± 2.8 years) and 50 healthy controls (mean age 8.3 ± 3.5 years) were included. The two regions of interest for speckle tracking were manually positioned at the anterior and posterior carotid arterial wall using a Philips iE33 (Philips Medical Systems, Bothell, WA, USA). The peak systolic strain, time to peak systolic strain, early systolic strain rate, and late systolic strain rate were continuously monitored between the two regions of interest. Furthermore, the intimal-medial thickness, stiffness ß, and pressure-elastic modulus, as conventional measures of arterial stiffness, were concurrently obtained. RESULTS: The peak systolic strain and late systolic strain rate differed significantly between the patients with Kawasaki disease and controls (6.69% versus 8.60%, p < 0.01, and -0.28/second versus -0.51/second, p < 0.0001, respectively). There was no difference in the time to peak systolic strain, early systolic strain rate, and conventional measures. CONCLUSIONS: The arteries of patients with Kawasaki disease appear to develop mild sclerotic changes shortly after the onset of the disease.

Thomsen-Friedenreich antigen exposure as a cause of Streptococcus pyogenes-associated hemolytic-uremic syndrome.

Infection with Streptococcus pyogenes, a Group A beta-hemolytic streptococcus (GAS), is a rare cause of hemolyticuremic syndrome (HUS). Invasive infections with Streptococcus pneumoniae that produce neuraminidase are a well-recognized cause of HUS without diarrhea. The Thomsen- Friedenreich antigen (T antigen) plays a role in the pathophysiology of pneumococcal HUS. We describe the case of a 3-year-old boy with GAS-associated HUS and show how T-antigen exposure was implicated in this case. He had no diarrhea and cultures for blood, urine, and stool were negative. The urinary pneumococcal antigen was negative; his direct Coombs test was positive. Glomerular capillary loops, tubular epithelium on his renal biopsy specimen, and red blood cells in his blood smear showed positive fluorescence with anti-T lectin. Although the pathogenesis of GAS-associated HUS is not well understood, T-antigen exposure may be implicated in some cases with GAS-associated HUS.

Diffusion-weighted MRI of exercise-induced acute renal failure (ALPE).

Acute renal failure with severe loin pain induced by anaerobic exercise (ALPE) is a rare condition that is accompanied by wedge-shaped contrast enhancement on computed tomography (CT) without evidence of rhabdomyolysis. In two pediatric cases with ALPE, we tried to determine the relationship between findings from CT and magnetic resonance imaging (MRI). Case 1 involved a 13-year-old Japanese girl with a diagnosis of ALPE with normo-uricemia. Contrast-enhanced CT after 24 and 48 h showed a wedge-shaped excretion delay for the contrast media. A clear wedge-shaped signal hyperintensity matching the CT images was obtained by diffusion-weighted MRI. Case 2 involved a 16-year-old boy who presented with a second attack of ALPE after diagnosis of ALPE with hypouricemia 1 year earlier. Only diffusion-weighted imaging was performed. Clear wedge-shaped signal hyperintensity was apparent, similar to Case 1. MRI is safer than contrast-enhanced CT for patients with ALPE. Diffusion-weighted MRI is a very useful examination for diagnosing ALPE, providing noninvasive detection of lesions peculiar to ALPE.

Aplastic anemia successfully treated with rituximab: the possible role of aplastic anemia-associated autoantibodies as a marker for response.

A 1-yr-old Japanese male infant developed hepatitis-associated aplastic anemia (AA), and anti-thymocyte globulin (ATG) plus cyclosporine A (CsA) was administered without any appreciable effects. Laboratory examination of the patient's serum obtained before therapy revealed various autoantibodies, such as PA-IgG, anti-platelets, anti-single-stranded DNA (ssDNA), and anti-double-stranded DNA (dsDNA) antibodies (Abs) in addition to anti-DRS-1 Abs and anti-moesin Abs, both of which are known to be detectable in approximately 40% of all patients presenting with AA. He was therefore treated with 17.5 mg/kg/d rituximab 5.5 months after ATG/CsA therapy. The same rituximab therapy was repeated three times once a month thereafter. His neutrophil counts started to increase 50 d after the first rituximab therapy and he achieved a complete remission at 16 months after the last rituximab administration. All of the autoantibodies including anti-ssDNA, dsDNA, DRS-1, and moesin became undetectable when he attained the remission. Anti-CD20 monoclonal antibody therapy may be effective in a subset of patients with AA characterized by the presence of autoantibodies.

Minimal residual disease-based augmented therapy in childhood acute lymphoblastic leukemia: a report from the Japanese Childhood Cancer and Leukemia Study Group.

BACKGROUND: The majority of minimal residual disease (MRD)-positive patients with acute lymphoblastic leukemia (ALL) have poor outcomes. The ALL2000 study was performed to evaluate the efficacy of augmented chemotherapy based on MRD-restratification in childhood ALL. PROCEDURE: Between 2000 and 2004, 305 eligible patients with precursor B or T-cell ALL were enrolled in the ALL2000 study. The ALL941-based therapy protocol utilized PCR MRD assays using Immunoglobulin and T-cell receptor gene rearrangements. They were initially stratified into three risk-groups according to leukocyte count and age, and MRD levels were measured at weeks 5 (TP1) and 12 (TP2) for a second stratification. From week 14, patients with MRD levels ≥ 10(-3) received an increase in therapy (one risk group higher), while the remainder continued to receive the initial risk-adapted therapy. RESULTS: The overall 5-year event-free survival (EFS) rate for ALL2000 was 79.7 ± 2.4%. MRD stratification was feasible for 234 of 301 patients (77%) who achieved complete remission. The EFS rate of the MRD stratifiable (MRD) group was 82.5 ± 2.6%, considerably superior to the 74.7 ± 5.7% of MRD non-stratifiable (Non-MRD) group (P = 0.084) and the 74.4 ± 2.1% for ALL 941 (P = 0.012). MRD-positive patients at TP2 showed inferior outcomes as compared with MRD-negative cases, but the difference did not reach a statistically significant level in any risk groups or immunophenotypes. CONCLUSIONS: These results suggest that augmented therapy for MRD-positive patients at TP2 contributed to better outcomes of the ALL2000 study.

Dense methylation of types 1 and 2 regulatory regions of the CD10 gene promoter in infant acute lymphoblastic leukemia with MLL/AF4 fusion gene.

SUMMARY: Infant acute lymphoblastic leukemia (ALL) displays distinct biologic and clinical features with a poor prognosis. The CD10-negative immunophenotype of infant ALL is a hallmark and provides a predictable signature of mixed-lineage leukemia (MLL) rearrangement. Although CD10 negativity reflects an earlier stage of B-cell development, complete IgH gene rearrangements (VDJH), found in almost half of the patients, show more mature IgH status. Discordance between immunophenotype and genotype of infant ALL suggests an aberrant process in immunophenotypic steps of differentiation or a secondary down-regulation of CD10 expression. In this study, CD10-negative infant ALL with MLL/AF4, CD10-positive infant ALL with germline MLL, CD10-positive pre-B ALL cell line, infant acute myeloid leukemia (AML; M5) with MLL/AF9 and pediatric AML (M2) with AML1/ETO were analyzed for VDJH status and methylation of CD10 gene promoters. Three of the 4 infant ALL samples showed complete rearrangements of the VDJH gene with productive joints. Bisulfite sequencing of CD10 type 1 and 2 promoters showed that more than 84% of the cytosine-phosphate-guanine (CpG) dinucleotides identified were methylated in all 3 CD10-negative infant ALL samples with MLL/AF4. The CpG dinucleotides distributed in the clusters of putative Sp1-binding sites and functionally active regulatory regions of the promoters were fully methylated. In contrast, none of the CpG dinucleotides were methylated in the CD10-positive ALL samples. Structural evidence of dense methylation in the CD10 gene promoter suggested that methylated transcription factor binding sites contribute to CD10 silencing as an epigenetic mechanism.

Outcome of recurrent or refractory acute lymphoblastic leukemia in infants with MLL gene rearrangements: A report from the Japan Infant Leukemia Study Group.

BACKGROUND: Despite the poor outcome of recurrent or refractory acute lymphoblastic leukemia (ALL) in infants with MLL gene rearrangement, few studies have focused on this specific group. We conducted a retrospective analysis of infants with recurrent or refractory ALL from two previous consecutive Japanese studies to clarify the characteristics and prognostic factors among these patients PROCEDURE: All recurrent or refractory ALL infants with MLL gene rearrangement (MLL-R) who were registered in two consecutive Japanese nation-wide multicentric trials (MLL96 and MLL98; between 1995 and 2001) were eligible for the study. RESULTS: Among 80 MLL-R ALL infants, 34 cases of recurrence and 5 induction failures occurred. The median duration of first remission was 5 months (range, 0-28 months). All patients underwent various salvage chemotherapies; remission was achieved in 40.5% (15/37). A total of 23 patients received subsequent hematopoietic stem cell transplantations (HSCT): 9 in remission, 12 without remission, and 2 with unknown status. With median follow-up period of 5.5 years, the 5-year overall survival (OS) rate after the second-line treatment was 25.6% +/- 6.9%. Young age (<3 months) and central nervous system involvement at initial diagnosis were associated with poor outcome; however, failure to achieve remission after salvage therapy was the sole independent poor prognostic factor in multivariate analysis (P = 0.01). CONCLUSIONS: The prognosis of infants with recurrent or refractory MLL-R ALL is extremely poor despite alternative treatments including HSCT; therefore, it is necessary to develop novel treatment strategies.