Elevation of serum fibroblast growth factor 23 level in a pediatric patient with lupus nephritis.

Fibroblast growth factor 23 (FGF-23), a hormone mainly secreted by osteocytes and osteoblasts, regulates phosphate and vitamin D levels. However, the in vivo significance of FGF-23 is not fully elucidated. This case report describes a 12-year-old girl with systemic lupus erythematosus (SLE), lupus nephritis, and an elevated serum FGF-23 level. The patient was treated with active vitamin D and oral sodium phosphate medications to manage low serum phosphate levels (2.2 mg/dL). Magnetic resonance imaging (MRI) revealed a high-intensity area in the left femur, but somatostatin receptor scintigraphy images did not indicate tumor-induced osteomalacia. SLE treatment using mycophenolate mofetil (1500 mg/day) was initiated, and serum complements levels increased as FGF-23 level increased. Serum FGF-23 level gradually decreased as urinary protein levels decreased after treatment with steroids; however, there was no change in the high-intensity area on MRI. Recent studies have reported that serum FGF-23 level is associated with iron deficiency and inflammation; yet, the mechanism related to these associations is not fully elucidated. The findings from this case suggest that elevated serum FGF-23 levels noted in our patient were related to silent lupus nephritis and lupus nephritis activity.

Acute kidney injury caused by ammonium acid urate crystals in diabetic ketoacidosis at the onset of type 1 diabetes mellitus.

SUMMARY: Ammonium acid urate (AAU) crystals are rare in industrialized countries. Furthermore, the number of children with diabetic ketoacidosis (DKA) who develop severe acute kidney injury (AKI) after hospitalization is small. We encountered two patients with AKI caused by AAU crystals during the recovery phase of DKA upon admission. They were diagnosed with severe DKA and hyperuricemia. Their urine volume decreased and AKI developed several days after hospitalization; however, acidosis improved in both patients. Urine sediment analysis revealed AAU crystals. They were treated with urine alkalization and diuretics. Excretion of ammonia in the urine and urine pH levels increased after treatment of DKA, which resulted in the formation of AAU crystals. In patients with severe DKA, the urine and urine sediment should be carefully examined as AAU can form in the recovery phase of DKA. LEARNING POINTS: Ammonium acid urate crystals could be formed in the recovery phase of diabetic ketoacidosis. Diabetic ketoacidosis patients may develop acute kidney injury caused by ammonium acid urate crystals. Urine and urine sediment should be carefully checked in patients with severe DKA who present with hyperuricemia and volume depletion.

Factors predicting endocrine late effects in childhood cancer survivors from a Japanese hospital.

We retrospectively analyzed endocrine late effects in 81 childhood cancer survivor (CCS) patients who had been referred to our endocrinology department in Chiba Children's Hospital between January 1, 2008 and December 31, 2016. Among 69 eligible patients (33 male, 36 female), endocrine late effects were identified in 56 patients (81.1%). The median age at the last visit to our endocrinology department was 17.4 years (range: 7.1-35.3 years). The most common primary cancer was acute lymphoblastic leukemia (22 patients, 31.8%). Forty-four patients (64%) were treated using radiation therapy. A primary brain tumor and high doses (≥6 g/m2) of cyclophosphamide were significantly associated with growth hormone deficiency (GHD). Our present study suggests that high doses of cyclophosphamide is a risk factor for GHD. Adult heights and pubertal growth spurts of patients treated with radiation therapy were significantly lower than patients not treated with radiation therapy. Our retrospective study reconfirmed that hematopoietic stem cell transplantation and chronic graft versus host disease (GVHD) were associated with elevated risks of primary hypothyroidism. However, it is unclear whether GVHD induces thyroid dysfunction. Gonadal radiation and busulfan were associated with primary hypogonadism as reported in previous studies. We found high doses of cyclophosphamide to be involved in pituitary disorders. We suggest that pediatric endocrinologists should discuss the potential effects of radiation therapy on adult height and pubertal growth spurt in CCS patients. Moreover, patients who have been treated with high doses of cyclophosphamide or have chronic GVHD require long-term follow-up for endocrine late effects.

Itm2a expression in the developing mouse first lower molar, and the subcellular localization of Itm2a in mouse dental epithelial cells.

Itm2a is a type II transmembrane protein with a BRICHOS domain. We investigated the temporospatial mRNA and protein expression patterns of Itm2a in the developing lower first molar, and examined the subcellular localization of Itm2a in murine dental epithelial (mDE6) cells. From the initiation to the bud stage, the in situ and protein signals of Itm2a were not detected in either the dental epithelial or mesenchymal cells surrounding the tooth bud. However, at the bell stage, these signals of Itm2a were primarily observed in the inner enamel epithelium of the enamel organ. After the initiation of the matrix formation, strong signals were detected in ameloblasts and odontoblasts. Itm2a showed a punctate pattern in the cytoplasm of the mDE6 cells. The perinuclear-localized Itm2a displayed a frequent overlap with the Golgi apparatus marker, GM130. A tiny amount of Itm2a was colocalized with lysosomes and endoplasmic reticulum. Minimal or no overlap between the Itm2a-EGFP signals with the other organelle markers for endoplasmic reticulum, lysosome and mitochondria used in this study noted in the cytoplasm. These findings suggest that Itm2a may play a role in cell differentiation during odontogenesis, rather than during the initiation of tooth germ formation, and may be related to the targeting of proteins associated with enamel and dentin matrices in the secretory pathway.

Induction of dental epithelial cell differentiation marker gene expression in non-odontogenic human keratinocytes by transfection with thymosin beta 4.

Previous studies have shown that the recombination of cells liberated from developing tooth germs develop into teeth. However, it is difficult to use human developing tooth germ as a source of cells because of ethical issues. Previous studies have reported that thymosin beta 4 (Tmsb4x) is closely related to the initiation and development of the tooth germ. We herein attempted to establish odontogenic epithelial cells from non-odontogenic HaCaT cells by transfection with TMSB4X. TMSB4X-transfected cells formed nodules that were positive for Alizarin-red S (ALZ) and von Kossa staining (calcium phosphate deposits) when cultured in calcification-inducing medium. Three selected clones showing larger amounts of calcium deposits than the other clones, expressed PITX2, Cytokeratin 14, and Sonic Hedgehog. The upregulation of odontogenesis-related genes, such as runt-related transcription factor 2 (RUNX2), Amelogenin (AMELX), Ameloblastin (AMBN) and Enamelin (ENAM) was also detected. These proteins were immunohistochemically observed in nodules positive for the ALZ and von Kossa staining. RUNX2-positive selected TMSB4X-transfected cells implanted into the dorsal subcutaneous tissue of nude mice formed matrix deposits. Immunohistochemically, AMELX, AMBN and ENAM were observed in the matrix deposits. This study demonstrated the possibility of induction of dental epithelial cell differentiation marker gene expression in non-odontogenic HaCaT cells by TMSB4X.

Chemoresistance to concanamycin A1 in human oral squamous cell carcinoma is attenuated by an HDAC inhibitor partly via suppression of Bcl-2 expression.

V-ATPase is involved in the acidification of the microenvironment around/in solid tumors, such as oral squamous cell carcinoma (OSCC). V-ATPase is thought to induce tumor invasion and multi-drug resistance in several malignant tumors, and it also contributes to maintaining the intracellular pH under an acidic microenvironment by inducing proton extrusion into the extracellular medium. However, there is little information regarding the effects of V-ATPase inhibitors on OSCCs. In this study, the effects of a V-ATPase inhibitor, concanamycin A1 (CMA), on the proliferation and apoptosis of OSCC were investigated in vitro. We used four OSCC cell lines, MISK81-5, SAS, HSC-4 and SQUU-B. Acridine orange staining revealed that the red fluorescence was reduced in all of the low concentration CMA-treated OSCC cells, indicating that the acidification of vesicular organelles in the OSCCs was prevented by the treatment with low-concentration of CMA. CMA treatment induced apoptosis in MISK81-5, SAS and HSC-4 cells, but not in SQUU-B cells. The p-p38 expression was not altered in CMA-treated SQUU-B cells, but their levels were increased in the other cells. The Bax/Bcl-2 ratio in CMA-treated SQUU-B cells was dramatically decreased in comparison with that in the other cell lines treated with CMA. However, when the SQUU-B cells were treated with CMA and a histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), the SQUU-B cells became more susceptible to the CMA-induced apoptosis. SAHA treatment led to a significantly decrease in the Bcl-2 expression in CMA-treated SQUU-B cells, resulting in a dramatically increased Bax/Bcl-2 ratio in comparison with that observed in the SQUU-B cells treated with CMA alone. These findings suggest that CMA could have an anti-tumor effect on OSCCs. In addition, combination of CMA with other agents, such as SAHA, could help improve the pro-apoptotic effects of CMA even in CMA-resistant OSCC cells.

Immunohistochemical expression of thymosin ß4 in ameloblastomas and odontomas.

Ameloblastoma is regarded to be a benign odontogenic tumor, but it is destructive, locally invasive and presents a high rate of recurrence. Thymosin ß4 (Tß4) is closely associated with tooth germ development. Tß4 also plays a role in malignant progression and invasion. However, little is known about the function of Tß4 in odontogenic tumors. Thus, we investigated Tß4 expression in ameloblastomas and compared it with odontomas. We immunohistochemically evaluated the expression of Tß4, ameloblastin (AMBN), amelogenin (AMEL) and enamelin (ENAM) in 57 samples of ameloblastomas from 40 patients, and also assessed the expression of these molecules in 11 cases of odontomas, two of ameloblastic fibro-odontomas and one of tooth germ-like structures without the formation of enamel and dentin. Tß4 signals were observed in almost all of the ameloblastomas. The signals were observed in both peripheral columnar cells and central polyhedral/angular cells. Similar findings were observed in tooth germ-like structures, and in the ameloblastomatous nests in the ameloblastic fibro-odontomas. These samples had negative results for AMBN, AMEL and ENAM. Meanwhile, Tß4 signals were not seen in the odontomas, although immunolabeling for AMBN, AMEL and ENAM was observed in the enamel matrix and in some ameloblasts. Ectomesenhymal regions in the odontomas were negative for staining with the antibodies for AMBN, AMEL and ENAM. These results suggest that Tß4 could be associated with morphogenesis and tumor invasion in the ameloblastoma, and that Tß4 may play a role in the behavior of ameloblastoma.

The expression and function of thymosin beta 10 in tooth germ development.

This study presents the expression pattern and functions of thymosin beta 10 (Tbeta10), a Tbeta4 homologue during the development of mouse lower first molars. An in situ signal of Tbeta10 was detected on embryonic day 10.5 (E10.5)-E15.5 mainly in dental mesenchymal cells as well as in dental epithelial cells, while Tbeta4 was expressed in dental epithelial cells. In the late bell stage, preodontoblasts with strong Tbeta10 expression and preameloblasts with strong Tbeta4 expression exhibited face-to-face localization, suggesting that an intimate cell-cell interaction might exist between preodontoblasts and preameloblasts to form dentin and enamel matrices. A strong Tbeta10 signal was found in odontoblasts in the lateral side of the dental pulp and in Hertwig’s epithelial root sheath, thus suggesting that Tbeta10 participates in the formation of the outline of the tooth root. An inhibition assay using Tbeta10-siRNA in E11.0 mandibles showed significant growth inhibition in the tooth germ. The Tbeta10-siRNA-treated E15.0 tooth germ also showed significant developmental arrest. The number of Ki67-positive cells significantly decreased in the Tbeta10-siRNA-treated mandibles. The cellular proliferative activity was also significantly suppressed in Tb10-siRNA-treated cultured mouse dental pulpal and epithelial cells. These results indicate that developmental arrest of the tooth germ might be caused by a reduction in cell proliferative activity. The stage-specific temporal and spatial expression pattern of Tbeta10 in the developing tooth germ is indicative of multiple functions of Tbeta10 in the developmental course from initiation to root formation of the tooth germ.