High-throughput Screening for Cushing Disease: Therapeutic Potential of Thiostrepton via Cell Cycle Regulation.

Cushing disease is a life-threatening disorder caused by autonomous secretion of ACTH from pituitary neuroendocrine tumors (PitNETs). Few drugs are indicated for inoperative Cushing disease, in particular that due to aggressive PitNETs. To explore agents that regulate ACTH-secreting PitNETs, we conducted high-throughput screening (HTS) using AtT-20, a murine pituitary tumor cell line characterized by ACTH secretion. For the HTS, we constructed a live cell-based ACTH reporter assay for high-throughput evaluation of ACTH changes. This assay was based on HEK293T cells overexpressing components of the ACTH receptor and a fluorescent cAMP biosensor, with high-throughput acquisition of fluorescence images. We treated AtT-20 cells with compounds and assessed ACTH concentrations in the conditioned media using the reporter assay. Of 2480 screened bioactive compounds, over 50% inhibition of ACTH secreted from AtT-20 cells was seen with 84 compounds at 10 µM and 20 compounds at 1 µM. Among these hit compounds, we focused on thiostrepton (TS) and determined its antitumor effects in both in vitro and in vivo xenograft models of Cushing disease. Transcriptome and flow cytometry analyses revealed that TS administration induced AtT-20 cell cycle arrest at the G2/M phase, which was mediated by FOXM1-independent mechanisms including downregulation of cyclins. Simultaneous TS administration with a cyclin-dependent kinase 4/6 inhibitor that affected the cell cycle at the G0/1 phase showed cooperative antitumor effects. Thus, TS is a promising therapeutic agent for Cushing disease. Our list of hit compounds and new mechanistic insights into TS effects serve as a valuable foundation for future research.

Neprilysin Inhibition Promotes Skeletal Growth via the CNP/NPR-B Pathway.

C-type natriuretic peptide (CNP) plays a crucial role in enhancing endochondral bone growth and holds promise as a therapeutic agent for impaired skeletal growth. To overcome CNP's short half-life, we explored the potential of dampening its clearance system. Neprilysin (NEP) is an endopeptidase responsible for catalyzing the degradation of CNP. Thus, we investigated the effects of NEP inhibition on skeletal growth by administering sacubitril, a NEP inhibitor, to C57BL/6 mice. Remarkably, we observed a dose-dependent skeletal overgrowth phenotype in mice treated with sacubitril. Histological analysis of the growth plate revealed a thickening of the hypertrophic and proliferative zones, mirroring the changes induced by CNP administration. The promotion of skeletal growth observed in wild-type mice treated with sacubitril was nullified by the knockout of cartilage-specific natriuretic peptide receptor B (NPR-B). Notably, sacubitril promoted skeletal growth in mice only at 3 to 4 weeks of age, a period when endogenous CNP and NEP expression was higher in the lumbar vertebrae. Additionally, sacubitril facilitated endochondral bone growth in organ culture experiments using tibial explants from fetal mice. These findings suggest that NEP inhibition significantly promotes skeletal growth via the CNP/NPR-B pathway, warranting further investigations for potential applications in people with short stature.

Prediction-based prompt levothyroxine replacement to prevent a hypothyroid state after immune-related adverse events involving the thyroid gland.

Immune checkpoint inhibitors (ICIs) are used for various malignancies, although they frequently cause immune-related adverse events involving the thyroid gland (thyroid irAEs). We conducted a retrospective cohort study to elucidate thyroid function outcomes. Fifty of 639 patients who received PD-1 blockade therapy met criteria and were divided into the following groups: thyrotoxicosis with subsequent hypothyroidism (Toxic-Hypo, n = 21); thyrotoxicosis without subsequent hypothyroidism (Toxic, n = 9); and hypothyroidism without prior thyrotoxicosis (Hypo, n = 20). The Toxic-Hypo group developed thyroid irAEs earlier than the Toxic group (26 vs. 91 days; p < 0.001), and had higher serum free T4 levels (3.210 vs. 1.880 ng/dL; p = 0.011). In addition, positive anti-thyroglobulin antibodies (TgAbs) at thyroid irAE onset were more common in the Toxic-Hypo group (93.3%) than in the Toxic group (0.0%; p = 0.005) and Hypo group (44.4%; p = 0.007). The Toxic-Hypo group developed severe hypothyroidism and required larger levothyroxine (LT4) doses than the Hypo group (75 vs. 25 µg/day; p = 0.007). We predicted that patients with positive TgAbs who developed severe thyrotoxicosis within 4 weeks after the first ICI administration would develop subsequent hypothyroidism. We treated 4 such patients with prompt LT4 replacement, characterized by LT4 initiation after thyrotoxicosis improvement and quick dose titration. Their euthyroid state was successfully maintained, in contrast with patients receiving conventional replacement. In conclusion, rapid-onset severe thyrotoxicosis in patients with TgAbs correlated with a high likelihood of subsequent hypothyroidism. Accordingly, prompt LT4 replacement is suggested to prevent a severely hypothyroid state.

Amino acid polymorphisms in human histocompatibility leukocyte antigen class II and proinsulin epitope have impacts on type 1 diabetes mellitus induced by immune-checkpoint inhibitors.

Introduction: Immune-checkpoint inhibitors are effective in various advanced cancers. Type 1 diabetes mellitus induced by them (ICI-T1DM) is a serious complication requiring prompt insulin treatment, but the immunological mechanism behind it is unclear. Methods: We examined amino acid polymorphisms in human histocompatibility leukocyte antigen (HLA) molecules and investigated proinsulin epitope binding affinities to HLA molecules. Results and Discussion: Twelve patients with ICI-T1DM and 35 patients in a control group without ICI-T1DM were enrolled in the study. Allele and haplotype frequencies of HLA-DRB1*04:05, DQB1*04:01, and most importantly DPB1*05:01 were significantly increased in patients with ICI-T1DM. In addition, novel amino acid polymorphisms in HLA-DR (4 polymorphisms), in DQ (12 polymorphisms), and in DP molecules (9 polymorphisms) were identified. These amino acid polymorphisms might be associated with the development of ICI-T1DM. Moreover, novel human proinsulin epitope clusters in insulin A and B chains were discovered in silico and in vitro peptide binding assays to HLA-DP5. In conclusion, significant amino acid polymorphisms in HLA-class II molecules, and conformational alterations in the peptide-binding groove of the HLA-DP molecules were considered likely to influence the immunogenicity of proinsulin epitopes in ICI-T1DM. These amino acid polymorphisms and HLA-DP5 may be predictive genetic factors for ICI-T1DM.

Pheochromocytoma Multisystem Crisis Complicated by Severe Acute Pancreatitis.

A 43-year-old man developed headache, dizziness, abdominal pain, and vomiting. His blood pressure was 203/121 mmHg, heart rate 122 beats/min, body temperature 39.1°C, and respiratory rate 24/min. He had elevated levels of creatinine at 2.95 mg/dL and lipase at 1,364 U/L as well as an extremely low calcium level at 5.2 mg/dL. Hypertriglyceridemia and hyperglycemia were seen. Chest and abdominal computed tomography showed interstitial pneumonia, severe pancreatitis, and a right adrenal tumor. The patient also developed vertebral artery dissection and medullary infarction. After right adrenalectomy, the patient was diagnosed with pheochromocytoma multisystem crisis (PMC). Acute pancreatitis might augment numerous life-threatening manifestations of PMC.

Serum ketone body measurement in patients with diabetic ketoacidosis.

Background: Diabetic ketoacidosis (DKA) is a critical manifestation in patients with diabetes mellitus. DKA has been conventionally diagnosed by the presence of hyperglycemia (blood glucose levels > 250 mg/dl) and metabolic acidosis (blood gas bicarbonate [HCO3 -] < 18 mmol/l and pH in blood gas < 7.30). However, quantitative evaluation of serum ketone bodies has not been established. The current study investigates serum ketone body levels in patients suspected for DKA. Methods: We have retrospectively evaluated patients with hyperglycemia whose serum ketone body levels at the outpatient clinic and emergency department were measured simultaneously with blood gas analysis during 2011-2019. Clinical backgrounds, severity of diabetes, serum ketone bodies, and blood gas factors were analyzed. Results: Seventy-two patients were enrolled in the study, after the exclusion of patients who had ketosis due to factors other than diabetes. Serum ketone body levels were negatively correlated with the levels of blood HCO3 - and pH. By receiver-operating-characteristic curve analyses, optimal cut-off values for diagnosis of DKA were determined at 6.3 mmol/l of beta-hydroxybutyrate, 1.4 mmol/l of acetoacetate, and 8.0 mmol/l of total ketone body, respectively. Moreover, serum ketone bodies appeared to effectively differentiate between type 1 and type 2 diabetes mellitus. The cut-off values were higher than those in previous reports. Conclusions: Serum ketone body levels were thought to be useful in the diagnosis of DKA. Further investigations with increased numbers of patients are required to establish the appropriate application of serum ketone bodies in patients with DKA. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-022-00581-2.

Beneficial effects of sodium glucose cotransporter 2 inhibitors on left ventricular mass in patients with diabetes mellitus.

BACKGROUND: Sodium glucose cotransporter 2 inhibitor (SGLT2i) has recently been suggested to reduce the risk of cardiovascular events. Left ventricular hypertrophy (LVH) is associated with cardiovascular events. Diabetic macroangiopathy is a crucial complication in patients with diabetes mellitus (DM). This study examined the effect of SGLT2i on LVH in patients with type 2 DM (T2DM). METHODS: The retrospective cohort study was conducted in consecutive outpatients with T2DM from 2010 to 2020. Left ventricular mass index (LVMI) was used as an indicator of LVH based on echocardiography. The minimum follow-up period was 1 year. After propensity score-matching for clinical profiles, patients who underwent annual echocardiography twice for a routine checkup and took SGLT2i were defined to the SGLT2i group, whereas patients without SGLT2 inhibitors were defined to the non-SGLT2 group. SGLT2i was administered after baseline echocardiography followed by a second examination. RESULTS: LVMI levels in the SGLT2i group (n = 169) significantly decreased from baseline compared with those in the non-SGLT2i group (n = 169), % changes in LVMI2.7(g/m2.7 ) in median (interquartile ranges [IQR]) were - 7.7 (-18.7, 2.5) vs -3.6 (-14.3, 5.8), respectively, P = 0.017). In a subgroup analysis, LVMI levels in the patients who had LVH in the SGLT2i group more significantly decreased than those without LVH, % changes in LVMI2.7(g/m2.7 ) in median (IQR) were -13.5 (-22.1, -2.4) vs -2.8 (-12.6, 9.8), respectively, P < 0.001). CONCLUSIONS: SGLT2i treatment was shown to improve LVH in patients with T2DM and may play a pivotal role in the future treatment of diabetic cardiovascular complications.

Can chimpanzee infants (Pan troglodytes) form categorical representations in the same manner as human infants (Homo sapiens)?

We directly compared chimpanzee infants and human infants for categorical representations of three global-like categories (mammals, furniture and vehicles), using the familiarization-novelty preference technique. Neither species received any training during the experiments. We used the time that participants spent looking at the stimulus object while touching it as a measure. During the familiarization phase, participants were presented with four familiarization objects from one of three categories (e.g. mammals). Then, they were tested with a pair of novel objects, one was a familiar-category object and another was a novel-category object (e.g. vehicle) in the test phase. The chimpanzee infants did not show significant habituation, whereas human infants did. However, most important, both species showed significant novelty-preference in the test phase. This indicates that not only human infants, but also chimpanzee infants formed categorical representations of a global-like level. Implications for the shared origins and species-specificity of categorization abilities, and the cognitive operations underlying categorization, are discussed.

Mutual exclusivity and taxonomic bias in combination lead preschoolers' word learning.

This study investigated preschoolers' use of two word-learning tendencies in combination. 22 Japanese preschoolers were tested on a task with three forced choices that demanded use of mutual exclusivity and taxonomic bias in the single trials. When presented an object whose label they had learned, an object from the same category as the learned object, and an object from another category, the children chose the third object, suggesting that they use the two constraints in combination. This tendency is discussed with respect to its specific application to word learning.