“Adipsic hypernatremia” is clinically characterized by chronic elevation of plasma [Na⁺] with an inappropriate lack of thirst and upward resetting of the osmotic set point for arginine vasopressin (AVP) secretion, combined with a relative deficiency of AVP, thereby resulting in persistent hypernatremia. Many cases are accompanied by structural lesions in the hypothalamus, pituitary gland, and circumventricular organs (CVOs). On the other hand, cases without structural lesions have been reported since the 1970s, but the pathophysiology was unknown for a long time. In 2010, Hiyama et al. reported that an anti-Na_x antibody response caused adipsic hypernatremia in a pediatric case with ganglioblastoma. In recent years, advances in clinical research have led researchers to recognize that an autoimmunological pathogenic mechanism might be associated with periventricular organs such as the subfornical organ (SFO). In addition, in pediatric cases diagnosed as ROHHAD (rapid-onset obesity with hypoventilation, hypothalamic dysfunction, autonomic dysregulation) syndrome, it has been reported that half of the cases have abnormal serum Na levels, and some research findings indicated an autoimmune mechanism acting on the organs of the hypothalamus and CVOs. Then, anti-ZSCAN1 antibody response was detected in cases diagnosed as ROHHAD-NET in 2022. In this review, by summarizing a series of studies on Na_x and ZSCAN1, which are expressed in the hypothalamus, pituitary gland, and SFO, I would like to describe the current findings of the autoimmune pathogenesis of adipsic hypernatremia.

Diabetic nephropathy (DN) is a common and serious complication of diabetes, contributing significantly to patient mortality. Complication of DN (CDN) ranks as the second leading cause of end-stage renal disease globally. To address this, understanding the genetic regulation underlying DN is crucial for personalized treatment strategies. In this study, we identified genes and lncRNAs associated with diabetes and diabetic nephropathy constructing a DN-related lncRNA–mRNA network (DNLMN). This network, characterized by scale-free biomolecular properties, generated through the study of topological properties, elucidates key regulatory interactions. Enrichment analysis of important network modules revealed critical biological processes and pathways involved in DN pathogenesis. In the second step, we investigated the differential expression and co-expression of hub nodes in diseased and normal individuals, identifying lncRNA-mRNA relationships implicated in disease regulation. Finally, we gathered DN-related single nucleotide polymorphisms (SNPs) and lncRNAs from the LincSNP 3.0 database. The DNLMN encompasses SNP-associated lncRNAs, and transcription factors (TFs) linked to differentially expressed lncRNAs between diseased and normal samples. These results underscore the significance of biomolecular networks in disease progression and highlighting the role of biomolecular variability contributes to personalized disease phenotyping and treatment.

Paeoniflorin (Pae) can improve diabetes mellitus (DM), especially endothelial dysfunction induced by high glucose (HG). Molecularly, the mechanism pertinent to Pae and DM lacks further in-depth research. Hence, this study determined the molecular mechanism of Pae in treating DM through network pharmacology. The target of Pae was analyzed by TCMSP database, and DM-related genes were dissected by Genecards database and Omim database. PPI network was constructed for cross targets through Cytoscape 3.9.1 and STRING platform. GO and KEGG analyses were carried out on the cross targets. Protein molecular docking verification was completed by AutoDockTools and Pymol programs. Human umbilical vein endothelial cells (HUVECs) were separately treated with HG, Pae (5, 10, 20 μM) and/or HRAS overexpression plasmids (oe-HRAS). The cell viability, apoptosis and the protein expressions of HRAS and Ras-GTP were evaluated. There were 50 cross targets between Pae and DM, and VEGFA, EGFR, HRAS, SRC and HSP90AA1 were the key genes identified by PPI network analysis. GO and KEGG analyses revealed signal paths such as Rap1 and Ras. Molecular docking results confirmed that Pae had a good binding ability with key genes. In HG-treated HUVECs, Pae dose-dependently facilitated cell viability, attenuated cell apoptosis, and dwindled the expressions of HRAS and Ras-GTP, but these effects of Pae were reversed by oe-HRAS. In conclusion, Pae regulates the viability and apoptosis of HG-treated HUVECs by inhibiting the expression of HRAS.

We previously demonstrated hepatic, cardiac, and skin inflammation in a high-fat diet-induced steatotic liver disease (SLD) model. However, the molecular mechanism in the kidneys in this model remains unclear. It has been recently reported that SGLT2 inhibitors improve chronic kidney disease (CKD). Therefore, we used this model to evaluate the effects of tofogliflozin on renal lipid metabolism and inflammation. Male 8–10-week-old C57Bl/6 mice were fed a high-fat/high-cholesterol/high-sucrose/bile acid (HF/HC/HS/BA) diet with 0.015% tofogliflozin (Tofo group) or an HF/HC/HS/BA diet alone (SLD group). After eight weeks, serum lipid profiles, histology, lipid content, and mRNA/microRNA and protein expression levels in the kidney were examined. The Tofo group showed significant reductions in body (26.9 ± 0.9 vs. 24.5 ± 1.0 g; p < 0.001) and kidney weight compared to those of the SLD group. Renal cholesterol (9.1 ± 1.6 vs. 7.5 ± 0.7 mg/g; p < 0.05) and non-esterified fatty acid (NEFA) (12.0 ± 3.0 vs. 8.4 ± 1.5 μEq/g; p < 0.01) were significantly decreased in the Tofo group. Transmission electron microscopy revealed the presence of fewer lipid droplets. mRNA sequencing analysis revealed that fatty acid metabolism-related genes were upregulated and NFκB signaling pathway-related genes were downregulated in the Tofo group. MicroRNA sequencing analysis indicated that miR-21a was downregulated and miR-204 was upregulated in the Tofo group. Notably, the expression of PPARα, which has been known to be negatively regulated by miR-21, was significantly increased, leading to enhancing β-oxidation genes, Acox1 and Cpt1 in the Tofo group. Tofogliflozin decreased renal cholesterol and NEFA levels and improved inflammation through the regulation of PPARα and miR-21a.

Parathyroid cancer (PC) is extremely resistant to chemotherapy and radiotherapy (RT), but hormonally functional by producing excessive parathyroid hormone (PTH), causing remarkable hypercalcemia even in biochemical disease recurrence. Accordingly, management of hypercalcemia by calcimimetics and bisphosphonates has been main treatment for unresectable PC. Here, we report a case of unresectable tumor mutational burden (TMB)-high recurrent PC that has been effectively controlled by pembrolizumab (PEM) with RT. A 48-year-old male patient, with previous history of left single parathyroidectomy for primary hyperparathyroidism, underwent surgeries for recurrent hyperparathyroidism at 47 and 48 years of age, and was pathologically diagnosed with PC. He was referred to our hospital due to persistent hypercalcemia and elevated PTH. The recurrent tumors were identified in the superior mediastinum and radically resected, then the hyperparathyroidism was improved. A FoundationOne^® CDx of the specimen called TMB-high. He demonstrated recurrent hyperparathyroidism at 49 years of age, and underwent a gross curative resection. However, hyperparathyroidism achieved only insufficient improvement, indicating biochemical residual cancer cells. PEM treatment was initiated in combination with RT to the left central-lateral neck and superior mediastinum. He successfully achieved evocalcet and zoledronate withdrawal, and the PTH level improvement was continuously observed for 8 months at present, with only grade 2 subclinical hypothyroidism. Interestingly, leukocyte fraction ratios were reversed corresponding to disease improvement. A combination of PEM and RT is a promising treatment of unresectable TMB-high PC. Recent evidence on the immunomodulatory effect of RT provides the rationale for the combination of RT and PEM.

HDR syndrome is an autosomal dominant disorder characterized by hypoparathyroidism (H), deafness (D), and renal dysplasia (R) caused by genetic variants of the GATA3 gene. We present the case of a 38-year-old Japanese man with HDR syndrome who exhibited hypoparathyroidism, sensorineural deafness, renal dysfunction, severe symptomatic hypocalcemia with Chvostek’s and Trousseau’s signs, and QT prolongation on electrocardiography. He had a family history of deafness and hypocalcemia. Genetic testing revealed a novel GATA3 gene variant at exon 2 (c.48delC), which induces a frameshift resulting in termination at codon 178, causing HDR syndrome. We summarized 45 Japanese cases of HDR syndrome with regard to the mode of onset (familial or sporadic) and the age at diagnosis. In addition, we summarized all previous cases of HDR syndrome with GATA3 gene variants. Mapping of previously reported genetic variants in HDR syndrome revealed that most missense variants were observed at exons 4 and 5 regions in the GATA3 gene. These two regions contain zinc finger domains, demonstrating their functional importance in GATA3 transcription. This review of literature provides a useful reference for diagnosing HDR syndrome and predicting the related future manifestations.

Adipsic diabetes insipidus (ADI) is characterized by central diabetes insipidus and an impaired thirst response to hyperosmolality, leading to hypernatremia. Hyponatremia observed in patients with ADI has been considered a complication of desmopressin therapy. Herein, we present a case of impaired thirst sensation and arginine vasopressin (AVP) secretion without desmopressin therapy, in which hyponatremia developed due to preserved non-osmotic AVP secretion. A 53-year-old woman with hypopituitarism, receiving hydrocortisone and levothyroxine, experienced hyponatremia three times over 5 months without desmopressin treatment. The first hyponatremic episode (120 mEq/L) was complicated by a urinary tract infection with a plasma AVP level of 33.8 pg/mL. Subsequent hyponatremia episodes occurred after administration of antipsychotic (124 mEq/L) and spontaneously (125 mEq/L) with unsuppressed plasma AVP levels (1.3 and 1.8 pg/mL, respectively). Hypertonic saline infusion did not affect AVP or copeptin levels. Regulating water intake using a sliding scale based on body weight prevented the recurrence of hyponatremia without the use of desmopressin. Except during infection, plasma AVP levels (1.3 ± 0.4 pg/mL) were not significantly correlated with serum sodium levels (r_s = –0.04, p = 0.85). In conclusion, we present a unique case of impaired thirst sensation and AVP secretion in which hyponatremia developed without desmopressin therapy. Preserved non-osmotic AVP secretion, possibly stimulated by glucocorticoid deficiency, may contribute to the development of hyponatremia in patients with ADI.

Elevated Fulminant Index (FI), [plasma glucose (PG)/glycosylated hemoglobin A1c (HbA1c)], was reportedly a sensitive index to differentiate fulminant type 1 diabetes (FT1D) from non-fulminant T1D (nFT1D). Aim of this study was to describe a better, but simpler index of FT1D. 49 and 52 patients with FT1D and nFT1D, respectively, were registered, and the discriminating ability of the rounded, normalized ratio, [PG (mmol/L) – 5.0]/[HbA1c (%) – 5.0], and the original ratio, [PG (mmol/L)]/[HbA1c (%)], was compared. Normalizing the ratio significantly raised its accuracy: area under the curve for receiver operating curve, AUROC (95%CI), 0.927 (0.858–0.964) and 0.851 (0.763–0.910), respectively, with and without the normalization (p < 0.01). Rounding of the figure into [PG (mmol/L) – 5.0]/[HbA1c (%) – 5.0] did not significantly sacrifice the discriminating ability of the index. Namely, the optimal cut point of rounded and normalized GAR, 10.0, showed 89.8% sensitivity. In conclusion, rounded, normalized (rn) GAR ≥10 (the rounded optimal cut-off) could be used for the snap diagnosis of FT1D.