promoting-3-d-aggregation-facs-purified-thymic-epithelial-cells-with

Promoting 3-D Aggregation of FACS Purified Thymic Epithelial Cells with EAK 16-II/EAKIIH6 Self-assembling Hydrogel

Thymus involution, associated with aging or pathological insults, results in diminished output of mature T-cells. Restoring the function of a failing ...

Allegheny Health Network

The pituitary-specific transcription factor 1 plays a key role in the development and differentiation of three pituitary cell types: somatotrophs, lactotrophs, and thyrotrophs. Several mutations of the human gene (called POU1F1) have been shown to be responsible for a phenotype of combined pituitary hormone deficiency involving GH, prolactin (PRL), and TSH.

Identification and functional analysis of the novel S179R POU1F1 mutation associated with combined pituitary hormone deficiency.

We experienced a case of fetal goitrous hypothyroidism in an infant delivered by a 33-year-old woman receiving 300 mg/day of propylthiouracil (PTU) for hyperthyroidism due to Graves' disease. A large fetal goiter (maximum diameter, 60 mm) was detected by magnetic resonance imaging (MRI) at 36 weeks of gestation. Initial fetal blood sampling revealed hypothyroidism with a serum thyroid-stimulating hormone (TSH) of 99 microIU/mL, free triiodothyronine (T(3)) of 1.97 pg/mL, and free thyroxine (T(4)) of 0.29 ng/dL. Consequently, a diagnosis of fetal goitrous hypothyroidism due to transplacental passage of maternal PTU was made. To reduce the risk of perinatal complications, 300 microg of levothyroxine sodium (L-T(4)) was administered into the maternal amniotic fluid twice between 37 and 38 weeks of gestation. Subsequent fetal MRI showed that the size of goiter had decreased. At 38 weeks and 5 days of gestation, a 3042-g male infant was born by cesarean section. There were no severe complications at delivery, although mild tachypnea was observed and the infant's thyroid gland was slightly enlarged. He was treated with L-T(4) for two weeks. At present, his growth and neurological development are normal. This case indicates that intrauterine therapy by the intraamniotic administration of L-T(4) can be effective in treating fetal goitrous hypothyroidism even during late gestation.

Successful intrauterine therapy for fetal goitrous hypothyroidism during late gestation.

Gaucher disease type 1 and type 3 are characterized by bone disease and hematological symptoms. It is known that monocyte/macrophage lineage is activated in Gaucher disease, and accordingly certain cytokines are elevated in blood. The aim of the present study was to explore the possible relationships between cytokines and bone remodeling and hematological abnormalities in this disease.

Roles of specific cytokines in bone remodeling and hematopoiesis in Gaucher disease.

Information on the phenotypic variations seen in patients with type 3 (chronic neuronopathic) Gaucher disease (GD) is still limited compared with type 1 GD. We retrospectively investigated the clinical features of 42 Japanese patients with type 3 GD. The 42 patients classified as type 3 fell into two groups: those diagnosed as having type 3 GD at diagnosis (group A; n = 24) and those thought to have type 1 at diagnosis but who later developed neurological symptoms (group B; n = 18). The genotype of group A patients varied widely; however, L444P/L444P and L444P/F213I genotypes accounted for 83% in group B. All the patients who did not receive enzyme replacement with alglucerase or imiglucerase (4 in group A, 2 in group B) died. Nineteen patients received enzyme replacement in group A; however, 7 of these died despite the therapy. On the other hand, 14 patients received enzyme replacement alone in group B and 13 of them survived. Among the ERT-treated patients who survived, only one of 12 in group A and 12 out of 13 in group B can walk unaided. In conclusion, some Japanese GD patients who are thought to have type 1 at diagnosis develop neurological symptoms during their clinical course, and careful observation is essential for patients with characteristic genotypes. Moreover, enzyme replacement alone might not have a sufficient effect on the early onset neurological symptoms in type 3 patients. A different treatment strategy is needed to improve the prognosis of these patients.

Clinical and genetic study of Japanese patients with type 3 Gaucher disease.

The N188S mutation in Gaucher disease is associated with myoclonus epilepsy. We performed genetic analysis on a patient with progressive myoclonus epilepsy, who had received antiepileptic drugs for over 10 years. We detected N188S/G199D on the gene encoding glucocerebrosidase. Mutant proteins carrying each mutation were expressed in COS-1 cells (a commonly used cell line which derives from kidney cells of the African green monkey). Measurements of enzymatic activity and Western blotting analysis were performed. When residual activities were measured, glucocerebrosidase with the N188S mutation exhibited 50% activity of the wild type, and with G199D, 7.4%. Neither mutation influenced the stability of the enzyme protein. These data suggested a diagnosis of Gaucher disease for this patient, and indicated that G199D is a novel mutation.

Gaucher disease patient with myoclonus epilepsy and a novel mutation.

Mutations in the ATP6V1B1 and the ATP6V0A4 genes cause primary autosomal-recessive distal renal tubular acidosis (dRTA). Large deletions of either gene in patients with dRTA have not been described.

Mutational analyses of the ATP6V1B1 and ATP6V0A4 genes in patients with primary distal renal tubular acidosis.

It is sometimes difficult to confirm the location of a microadenoma in Cushing disease. Recently, we experienced an 11-yr-old female case of Cushing disease with hyperprolactinemia. She was referred to our hospital because of decrease of height velocity with body weight gain. On admission, she had typical symptoms of Cushing syndrome. Although no pituitary microadenomas were detected on 1.5 Tesla MRI of the brain, endocrinological examinations including IPS and CS sampling were consistent with Cushing disease with hyperprolactinemia. Oral administration of methyrapone instead of neurosurgery was started after discharge, but subsequent 3 Tesla MRI of the brain clearly demonstrated a 3-mm less-enhanced lesion in the left side of the pituitary gland. Finally, transsphenoidal surgery was performed, and a 3.5-mm left-sided microadenoma was resected. Compared with 1.5 Tesla MRI, 3 Tesla MRI offers the advantage of a higher signal to noise ratio (SNR), which provides higher resolution and proper image quality. Therefore, 3 Tesla MRI is a very useful tool to localize microadenomas in Cushing disease in children as well as in adults. It will be the first choice of radiological examinations in suspected cases of Cushing disease.

Diagnostic usefulness of 3 tesla MRI of the brain for cushing disease in a child.

We have identified a novel mutation of the arginine vasopressin receptor 2 (AVPR2) gene in a case of congenital X-linked nephrogenic diabetes insipidus (NDI). The patient was a 2-mo-old Japanese boy with persistent fever and failure to thrive. He was diagnosed as having congenital NDI by clinical and laboratory findings. Molecular analysis demonstrated that he was hemizygous for a G to C transversion in exon 2 of the AVPR2 gene which resulted in a glycine to arginine substitution (G107R) at the 107th codon of the first extracellular loop. His mother was heterozygous for the same mutation. We speculated that the G107R mutation would interfere with the binding capacity of the AVPR2, since G107R is located near F105 and R106, both of which are crucial for ligand binding. In cases of X-linked NDI, mutations in the AVPR2 gene are distributed widely. Thus, DNA analysis throughout the gene is of clinical value for the identification of female carriers, and it also gives precise information for genetic counseling.

A novel mutation of the arginine vasopressin receptor 2 gene in a patient with congenital nephrogenic diabetes insipidus.

For reasons not fully understood, patients with an organ-specific autoimmune disease have increased risks of developing autoimmune responses against other organs/tissues. We identified ICA69, a known β-cell autoantigen in Type 1 diabetes, as a potential common target in multi-organ autoimmunity. NOD mice immunized with ICA69 polypeptides exhibited exacerbated inflammation not only in the islets, but also in the salivary glands. To further investigate ICA69 autoimmunity, two genetically modified mouse lines were generated to modulate thymic ICA69 expression: the heterozygous ICA69(del/wt) line and the thymic medullary epithelial cell-specific deletion Aire-ΔICA69 line. Suboptimal central negative selection of ICA69-reactive T-cells was observed in both lines. Aire-ΔICA69 mice spontaneously developed coincident autoimmune responses to the pancreas, the salivary glands, the thyroid, and the stomach. Our findings establish a direct link between compromised thymic ICA69 expression and autoimmunity against multiple ICA69-expressing organs, and identify a potential novel mechanism for the development of multi-organ autoimmune diseases.

Compromised central tolerance of ICA69 induces multiple organ autoimmunity.

Non-alcoholic fatty liver disease (NAFLD) is one of the most common forms of chronic liver diseases closely associated with obesity and insulin resistance; deficient growth hormone (GH) action in liver has been implicated as a mechanism. Here, we investigated the evolution of NAFLD in aged mice with liver-specific GHR deletion.

Evolution of hepatic steatosis to fibrosis and adenoma formation in liver-specific growth hormone receptor knockout mice.

Herein, we highlight the technical feasibility of generating a functional mini thymus with a novel hydrogel system, based on a peptide-based self-assembly platform that can induce the formation of 3-D thymic epithelial cell (TEC) clusters. Amphiphilic peptide EAK16-II co-assembled with its histidinylated analogue EAKIIH6 into beta-sheet fibrils. When adaptor complexes (recombinant protein A/G molecules loaded with both anti-His and anti-EpCAM IgGs) were added to the mix, TECs were tethered to the hydrogel and formed 3-D mini clusters. TECs bound to the hydrogel composites retained their molecular properties; and when transplanted into athymic nude mice, they supported the development of functional T-cells. These mini thymic units of TECs can be useful in clinical applications to reconstitute T-cell adaptive immunity.

Bioengineering mini functional thymic units with EAK16-II/EAKIIH6 self-assembling hydrogel.

One of the major obstacles in organ transplantation is to establish immune tolerance of allografts. Although immunosuppressive drugs can prevent graft rejection to a certain degree, their efficacies are limited, transient, and associated with severe side effects. Induction of thymic central tolerance to allografts remains challenging, largely because of the difficulty of maintaining donor thymic epithelial cells in vitro to allow successful bioengineering. Here, the authors show that three-dimensional scaffolds generated from decellularized mouse thymus can support thymic epithelial cell survival in culture and maintain their unique molecular properties. When transplanted into athymic nude mice, the bioengineered thymus organoids effectively promoted homing of lymphocyte progenitors and supported thymopoiesis. Nude mice transplanted with thymus organoids promptly rejected skin allografts and were able to mount antigen-specific humoral responses against ovalbumin on immunization. Notably, tolerance to skin allografts was achieved by transplanting thymus organoids constructed with either thymic epithelial cells coexpressing both syngeneic and allogenic major histocompatibility complexes, or mixtures of donor and recipient thymic epithelial cells. Our results demonstrate the technical feasibility of restoring thymic function with bioengineered thymus organoids and highlight the clinical implications of this thymus reconstruction technique in organ transplantation and regenerative medicine.

Article	Year
Identification and functional analysis of the novel S179R POU1F1 mutation associated with combined pituitary hormone deficiency. The Journal of clinical endocrinology and metabolism\| PubMed ID: 16968807	2006
Successful intrauterine therapy for fetal goitrous hypothyroidism during late gestation. Endocrine journal\| PubMed ID: 17917306	2007
Roles of specific cytokines in bone remodeling and hematopoiesis in Gaucher disease. Pediatrics international : official journal of the Japan Pediatric Society\| PubMed ID: 18045304	2007
Clinical and genetic study of Japanese patients with type 3 Gaucher disease. Molecular genetics and metabolism\| PubMed ID: 19481486	2009
Gaucher disease patient with myoclonus epilepsy and a novel mutation. Pediatric neurology\| PubMed ID: 20004867	2010
Mutational analyses of the ATP6V1B1 and ATP6V0A4 genes in patients with primary distal renal tubular acidosis. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association\| PubMed ID: 23729491	2013
Diagnostic usefulness of 3 tesla MRI of the brain for cushing disease in a child. Clinical pediatric endocrinology : case reports and clinical investigations : official journal of the Japanese Society for Pediatric Endocrinology\| PubMed ID: 23926401	2011
A novel mutation of the arginine vasopressin receptor 2 gene in a patient with congenital nephrogenic diabetes insipidus. Clinical pediatric endocrinology : case reports and clinical investigations : official journal of the Japanese Society for Pediatric Endocrinology\| PubMed ID: 24790307	2005
Compromised central tolerance of ICA69 induces multiple organ autoimmunity. Journal of autoimmunity\| PubMed ID: 25088457	2014
Evolution of hepatic steatosis to fibrosis and adenoma formation in liver-specific growth hormone receptor knockout mice. Frontiers in endocrinology\| PubMed ID: 25566190	2014
Bioengineering mini functional thymic units with EAK16-II/EAKIIH6 self-assembling hydrogel. Clinical immunology (Orlando, Fla.)\| PubMed ID: 25805654	2015
Bioengineering Thymus Organoids to Restore Thymic Function and Induce Donor-Specific Immune Tolerance to Allografts. Molecular therapy : the journal of the American Society of Gene Therapy\| PubMed ID: 25903472	2015

Asako Tajima

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