Single-Nucleus Analysis Reveals Tumor Heterogeneity of Aldosterone-Producing Adenoma.

BACKGROUND: Recent advances in omics techniques have allowed detailed genetic characterization of aldosterone-producing adenoma (APA). The pathogenesis of APA is characterized by tumorigenesis-associated aldosterone synthesis. The pathophysiological intricacies of APAs have not yet been elucidated at the level of individual cells. Therefore, a single-cell level analysis is speculated to be valuable in studying the differentiation process of APA. METHODS: We conducted single-nucleus RNA sequencing of APAs with KCNJ5 mutation and nonfunctional adenomas obtained from 3 and 2 patients, respectively. RESULTS: The single-nucleus RNA sequencing revealed the intratumoral heterogeneity of APA and identified cell populations consisting of a shared cluster of nonfunctional adenoma and APA. In addition, we extracted 2 cell fates in APA and obtained a cell population specialized in aldosterone synthesis. Genes related to ribosomes and neurodegenerative diseases were upregulated in 1 of these fates, whereas those related to the regulation of glycolysis were upregulated in the other fate. Furthermore, the total RNA reads in the nucleus were higher in hormonally activated clusters, indicating a marked activation of transcription per cell. CONCLUSIONS: The single-nucleus RNA sequencing revealed intratumoral heterogeneity of APA with KCNJ5 mutation. The observation of 2 cell fates in KCNJ5-mutated APAs provides the postulation that a heterogeneous process of cellular differentiation was implicated in the pathophysiological mechanisms underlying APA tumors.

Increased serum extracellular vesicle miR-144-3p and miR-486a-3p in a mouse model of adipose tissue regeneration promote hepatocyte proliferation by targeting Txnip.

Adipose-derived stem cells are expected to be applied to regenerative medicine for various incurable diseases including liver cirrhosis. Although microRNAs contained in extracellular vesicles (EV-miRNAs) have been implicated in their regenerative effects, the precise mechanism has not been fully elucidated. Tamoxifen-inducible adipocyte-specific insulin receptor knockout (iFIRKO) mice are known to exhibit acute adipose tissue regeneration with increased numbers of adipose stem and progenitor cells (ASPCs). Because adipose tissue is the major source of circulating EV-miRNAs, we investigated alterations in serum EV-miRNAs in iFIRKO mice. A comprehensive analysis using miRNA sequencing on serum EVs revealed that most EV-miRNAs were decreased due to the loss of mature adipocytes, but there were 19 EV-miRNAs that were increased in the serum of iFIRKO mice. Among them, miR-144-3p and miR-486a-3p were found to be increased in the liver as well as serum EVs. While the expression levels of pri-miR-144-3p and pri-miR-486a-3p were not increased in the liver, they were elevated in the adipose tissue, suggesting that these miRNAs may be delivered from ASPCs increased in the adipose tissue to the liver via EVs. Increased hepatocyte proliferation was observed in the liver of iFIRKO mice, and we found that both miR-144-3p and miR-486a-3p have a function to promote hepatocyte proliferation by suppressing Txnip expression as a target gene. miR-144-3p and miR-486a-3p can be candidate therapeutic tools for conditions requiring hepatocyte proliferation, such as liver cirrhosis, and our current study suggests that examining EV-miRNAs secreted in vivo may lead to the discovery of miRNAs involved in regenerative medicine that have not been identified by in vitro analysis.

Long-term effects of primary aldosteronism treatment on patients with primary aldosteronism and chronic kidney disease.

OBJECTIVE: Primary aldosteronism (PA) is a major cause of secondary hypertension and is associated with chronic renal injury. The glomerular filtration rate (GFR) in PA rapidly decreases after the removal of glomerular hyperfiltration due to aldosterone excess by adrenalectomy (ADX) or mineralocorticoid receptor antagonist (MRA) treatment and is stable in the long term. However, the effects of these treatments on the long-term renal function of PA patients with chronic kidney disease (CKD) is not well understood. DESIGN AND PATIENTS: In this single-center, retrospective study, acute and chronic changes in the estimated GFR (eGFR) were examined in 107 patients with PA, including 49 patients with post-treatment CKD　defined as eGFR < 60 ml/min/1.73 m2 . RESULTS: The reduction in eGFR observed 1 month after ADX in the CKD group (N = 31) was -20.1 ± 8.2 ml/min/1.73 m2 . Multivariate analysis showed that pre-treatment eGFR and plasma aldosterone concentration were independent predictive factors of the acute reduction in eGFR after ADX. The reduction of eGFR observed 1 month after MRA administration in the post-treatment CKD group (N = 18) was -9.2 ± 5.9 ml/min/1.73 m2 . Multivariate analysis showed that the duration of hypertension and pre-treatment eGFR were independent predictive factors of the acute reduction in eGFR after ADX administration. In 20 patients with CKD (N = 12 ADX and N = 8 MRA) followed for more than 5 years post-treatment, there was no further significant decline in eGFR over a follow-up period of 7 (6, 8) years nor any difference between the two treatment modalities. CONCLUSIONS: Our study suggests that treatment of PA in stage 3 CKD is safe and useful in preventing renal injury.

Heterogeneous circulating miRNA profiles of PBMAH.

Objective: Primary bilateral macronodular adrenal hyperplasia (PBMAH), a rare cause of Cushing syndrome, is often diagnosed as a bilateral adrenal incidentaloma with subclinical cortisol production. Circulating microRNAs (miRNAs) are a characteristic of adrenocortical adenomas, but miRNA expression in PBMAH has not been investigated. We aimed to evaluate the circulating miRNA expression in patients with PBMAH and compare them with those in patients with non-functioning adrenocortical adenoma (NFA) and cortisol-producing adrenocortical adenoma (CPA). Methods: miRNA profiling of plasma samples from four, five, and five patients with NFA, CPA, and PBMAH, respectively, was performed. Selected miRNA expressions were validated using quantitative RT-PCR. Results: PBMAH samples showed distinct miRNA expression signatures on hierarchical clustering while NFA and CPA samples were separately clustered. PBMAH was distinguished from the adenoma group of NFA and CPA by 135 differentially expressed miRNAs. Hsa-miR-1180-3p, hsa-miR-4732-5p, and hsa-let-7b-5p were differentially expressed between PBMAH and adenoma (P = 0.019, 0.006, and 0.003, respectively). Furthermore, PBMAH could be classified into two subtypes based on miRNA profiling: subtype 1 with a similar profile to those of adenoma and subtype 2 with a distinct profile. Hsa-miR-631, hsa-miR-513b-5p, hsa-miR-6805-5p, and hsa-miR-548av-5p/548k were differentially expressed between PBMAH subtype 2 and adenoma (P = 0.027, 0.027, 0.027, and 1.53E-04, respectively), but not between PBMAH, as a whole, and adenoma. Conclusion: Circulating miRNA signature was identified specific for PBMAH. The existence of subtype-based miRNA profiles may be associated with the pathophysiological heterogeneity of PBMAH.

Clinical outcomes of 20 Japanese patients with insulinoma treated with diazoxide.

Diazoxide is recognized as an effective medical treatment for insulinoma. However, due to its adverse effects, such as fluid retention, it is sometimes difficult to employ diazoxide at an effective dose in clinical practice. This study aimed to clarify the clinical factors, which may affect efficacy and safety of the diazoxide treatment. We retrospectively evaluated the medical records of 20 patients with insulinoma including 4 malignant cases. The patients were divided into two groups according to the presence or absence of favorable outcomes or adverse effects, and the clinical features of both groups were compared. Diazoxide was effective and ineffective in each 9 patients, respectively. In other 2 cases, the efficacy could not be determined. In the effective group, all patients had benign insulinoma. Additionally, the tumor size determined by imaging test was tended to smaller than the ineffective group but not statistically significant when malignant cases were excluded (p = 0.065). Fluid retention was observed more frequently in females than in males (p = 0.025). Five patients displayed unacceptable thrombocytopenia within a few weeks after the administration of diazoxide. In these patients, the diazoxide dose was significantly higher than that in the other patients [400 mg/day (250-500 mg/day) vs. 225 mg/day (50-425 mg/day), p = 0.027]. These findings may be informative in determining the indication and dose of diazoxide against insulinoma. In addition, a careful evaluation of platelet count would be required for a few weeks after the initiation of diazoxide treatment.

Efficacy and safety of sitagliptin for the treatment of diabetes mellitus complicated by chronic liver injury.

AIM: To investigate the efficacy and safety of a dipeptidyl peptidase-4 inhibitor, sitagliptin, for treating diabetes mellitus complicated by chronic liver injury. METHODS: Sitagliptin was administered for 13.7 ± 10.1 months to 122 patients with DM complicated by chronic liver injury (including 19 patients with liver cirrhosis), and changes in hemoglobin A1c (HbA1c) and liver enzymes (transaminases, etc.) were evaluated. RESULTS: HbA1c was reduced from 8.48 ± 1.43% to 7.87 ± 1.35% (P < 0.001). Among liver enzymes, alanine aminotransferase (ALT) levels improved from 75.1 ± 45.2 to 65.8 ± 35.8 IU/L (P = 0.012) and gamma-glut amyl-trans peptidase from 155.2 ± 161.1 to 133.2 ± 127.4 IU/L (P = 0.044). Among the causes of liver injury, non-alcoholic fatty liver disease and alcoholic liver disease both showed the reductions in HbA1c with no deterioration of liver enzymes. An analysis of 19 patients with liver cirrhosis also showed reductions in HbA1c with no deterioration of liver enzymes. CONCLUSION: It is suggested that sitagliptin can be administered effectively and safely to patients with diabetes mellitus complicated by chronic liver injury, including liver cirrhosis.

A Case of Rathke's Cleft Cyst Associated with Transient Central Adrenal Insufficiency and Masked Diabetes Insipidus.

A 73-year-old woman admitted to our hospital because of headache, poor appetite, malaise, weight loss, and vomiting was found to have central adrenal insufficiency and thyrotoxicosis due to silent thyroiditis. Polyuria developed after replacement with glucocorticoid (masked diabetes insipidus), which was controlled with nasal administration of desmopressin. Magnetic resonance imaging of the brain showed a large cystic pituitary mass (18 × 18 × 12 mm) extending suprasellarly to the optic chiasm. Transsphenoidal surgery revealed that the pituitary tumor was Rathke's cleft cyst. Following surgery, replacement with neither glucocorticoid nor desmopressin was needed any more. Therefore, it is suggested that Rathke's cleft cyst is responsible for the masked diabetes insipidus and the central insufficiency. Furthermore, it is speculated that thyrotoxicosis with painless thyroiditis might induce changes from subclinical adrenal insufficiency to transiently overt insufficiency.