Functional calcium-responsive parathyroid glands generated using single-step blastocyst complementation.

Patients with permanent hypoparathyroidism require lifelong replacement therapy to avoid life-threatening complications, The benefits of conventional treatment are limited, however. Transplanting a functional parathyroid gland (PTG) would yield better results. Parathyroid gland cells generated from pluripotent stem cells in vitro to date cannot mimic the physiological responses to extracellular calcium that are essential for calcium homeostasis. We thus hypothesized that blastocyst complementation (BC) could be a better strategy for generating functional PTG cells and compensating loss of parathyroid function. We here describe generation of fully functional PTGs from mouse embryonic stem cells (mESCs) with single-step BC. Using CRISPR-Cas9 knockout of Glial cells missing2 (Gcm2), we efficiently produced aparathyroid embryos for BC. In these embryos, mESCs differentiated into endocrinologically mature PTGs that rescued Gcm2-/- mice from neonatal death. The mESC-derived PTGs responded to extracellular calcium, restoring calcium homeostasis on transplantation into mice surgically rendered hypoparathyroid. We also successfully generated functional interspecies PTGs in Gcm2-/- rat neonates, an accomplishment with potential for future human PTG therapy using xenogeneic animal BC. Our results demonstrate that BC can produce functional endocrine organs and constitute a concept in treatment of hypoparathyroidism.

Biological roles of growth hormone/prolactin from an evolutionary perspective.

Although growth hormone (GH) and prolactin (PRL) are usually recognized as pituitary hormones, their expression is not restricted to the adenohypophysis and can also be found in extra-pituitary tissues including placenta. Furthermore, GH, PRL, and their receptors structurally belong to the cytokine family of proteins, and indeed they have remarkable pleiotropic effects. In this review, we analyzed the biological roles of GH/PRL from an evolutionary perspective. We have recognized that the biological significance of GH/PRL can be summarized as follows: cytokines (metabokines) that regulate the shift of nutrients and even of whole bodies to live in the most appropriate environment(s) for conducting growth and reproduction. In this sense, the common keyword of the two metabokines is "shift" for environmental adaptation. Considering that these metabokines flexibly changed their biological roles, GH/PRL may have played important roles during vertebrate evolution.

Effects of tubastatin A on adrenocorticotropic hormone synthesis and proliferation of AtT-20 corticotroph tumor cells.

Cushing's disease is an endocrine disorder characterized by hypercortisolism, mainly caused by autonomous production of ACTH from pituitary adenomas. Autonomous ACTH secretion results in excess cortisol production from the adrenal glands, and corticotroph adenoma cells disrupt the normal cortisol feedback mechanism. Pan-histone deacetylase (HDAC) inhibitors inhibit cell proliferation and ACTH production in AtT-20 corticotroph tumor cells. A selective HDAC6 inhibitor has been known to exert antitumor effects and reduce adverse effects related to the inhibition of other HDACs. The current study demonstrated that the potent and selective HDAC6 inhibitor tubastatin A has inhibitory effects on proopiomelanocortin (Pomc) and pituitary tumor-transforming gene 1 (Pttg1) mRNA expression, involved in cell proliferation. The phosphorylated Akt/Akt protein levels were increased after treatment with tubastatin A. Therefore, the proliferation of corticotroph cells may be regulated through the Akt-Pttg1 pathway. Dexamethasone treatment also decreased the Pomc mRNA level. Combined tubastatin A and dexamethasone treatment showed additive effects on the Pomc mRNA level. Thus, tubastatin A may have applications in the treatment of Cushing's disease.

Hypothalamic Regulation of Corticotropin-Releasing Factor under Stress and Stress Resilience.

This review addresses the molecular mechanisms of corticotropin-releasing factor (CRF) regulation in the hypothalamus under stress and stress resilience. CRF in the hypothalamus plays a central role in regulating the stress response. CRF stimulates adrenocorticotropic hormone (ACTH) release from the anterior pituitary. ACTH stimulates glucocorticoid secretion from the adrenal glands. Glucocorticoids are essential for stress coping, stress resilience, and homeostasis. The activated hypothalamic-pituitary-adrenal axis is suppressed by the negative feedback from glucocorticoids. Glucocorticoid-dependent repression of cAMP-stimulated Crf promoter activity is mediated by both the negative glucocorticoid response element and the serum response element. Conversely, the inducible cAMP-early repressor can suppress the stress response via inhibition of the cAMP-dependent Crf gene, as can the suppressor of cytokine signaling-3 in the hypothalamus. CRF receptor type 1 is mainly involved in a stress response, depression, anorexia, and seizure, while CRF receptor type 2 mediates "stress coping" mechanisms such as anxiolysis in the brain. Differential effects of FK506-binding immunophilins, FKBP4 and FKBP5, contribute to the efficiency of glucocorticoids under stress resilience. Together, a variety of factors contribute to stress resilience. All these factors would have the differential roles under stress resilience.

Differential Effects of Fkbp4 and Fkbp5 on Regulation of the Proopiomelanocortin Gene in Murine AtT-20 Corticotroph Cells.

The hypothalamic-pituitary-adrenal axis is stimulated in response to stress. When activated, it is suppressed by the negative feedback effect of glucocorticoids. Glucocorticoids directly inhibit proopiomelanocortin (Pomc) gene expression in the pituitary. Glucocorticoid signaling is mediated via glucocorticoid receptors, 11ß-hydroxysteroid dehydrogenases, and the FK506-binding immunophilins, Fkbp4 and Fkbp5. Fkbp4 and Fkbp5 differentially regulate dynein interaction and nuclear translocation of the glucocorticoid receptor, resulting in modulation of the glucocorticoid action. Here, we explored the regulation of Fkbp4 and Fkbp5 genes and their proteins with dexamethasone, a major synthetic glucocorticoid drug, in murine AtT-20 corticotroph cells. To elucidate further roles of Fkbp4 and Fkbp5, we examined their effects on Pomc mRNA levels in corticotroph cells. Dexamethasone decreased Pomc mRNA levels as well as Fkpb4 mRNA levels in mouse corticotroph cells. Dexamethasone tended to decrease Fkbp4 protein levels, while it increased Fkpb5 mRNA and its protein levels. The dexamethasone-induced decreases in Pomc mRNA levels were partially canceled by Fkbp4 knockdown. Alternatively, Pomc mRNA levels were further decreased by Fkbp5 knockdown. Thus, Fkbp4 contributes to the negative feedback of glucocorticoids, and Fkbp5 reduces the efficiency of the glucocorticoid effect on Pomc gene expression in pituitary corticotroph cells.

Eicosapentaenoic acid down-regulates expression of the selenoprotein P gene by inhibiting SREBP-1c protein independently of the AMP-activated protein kinase pathway in H4IIEC3 hepatocytes.

Selenoprotein P (encoded by SELENOP in humans, Selenop in rat), a liver-derived secretory protein, induces resistance to insulin and vascular endothelial growth factor (VEGF) in type 2 diabetes. Suppression of selenoprotein P may provide a novel therapeutic approach to treating type 2 diabetes; however, few drugs inhibiting SELENOP expression in hepatocytes have been identified. The present findings demonstrate that eicosapentaenoic acid (EPA) suppresses SELENOP expression by inactivating sterol regulatory element-binding protein-1c (SREBP-1c, encoded by Srebf1 in rat) in H4IIEC3 hepatocytes. Treatment with EPA caused concentration- and time-dependent reduction in SELENOP promoter activity. EPA activated AMP-activated protein kinase (AMPK); however, the inhibitory effect of EPA on SELENOP promoter activity was not canceled with an AMPK inhibitor compound C and dominant-negative AMPK transfection. Deletion mutant promoter assays and computational analysis of transcription factor-binding sites conserved among the species resulted in identification of a sterol regulatory element (SRE)-like site in the SELENOP promoter. A chromatin immunoprecipitation (ChIP) assay revealed that EPA decreases binding of SREBP-1c to the SELENOP promoter. Knockdown of Srebf1 resulted in a significant down-regulation of Selenop expression. Conversely, SREBP-1c overexpression inhibited the suppressive effect of EPA. These data provide a novel mechanism of action for EPA involving improvement of systemic insulin sensitivity through the regulation of selenoprotein P production independently of the AMPK pathway and suggest an additional approach to developing anti-diabetic drugs.

Diagnosis and treatment of adrenal insufficiency including adrenal crisis: a Japan Endocrine Society clinical practice guideline [Opinion].

This clinical practice guideline of the diagnosis and treatment of adrenal insufficiency (AI) including adrenal crisis was produced on behalf of the Japan Endocrine Society. This evidence-based guideline was developed by a committee including all authors, and was reviewed by a subcommittee of the Japan Endocrine Society. The Japanese version has already been published, and the essential points have been summarized in this English language version. We recommend diagnostic tests, including measurement of basal cortisol and ACTH levels in combination with a rapid ACTH (250 µg corticotropin) test, the CRH test, and for particular situations the insulin tolerance test. Cut-off values in basal and peak cortisol levels after the rapid ACTH or CRH tests are proposed based on the assumption that a peak cortisol level ≥18 µg/dL in the insulin tolerance test indicates normal adrenal function. In adult AI patients, 15-25 mg hydrocortisone (HC) in 2-3 daily doses, depending on adrenal reserve and body weight, is a basic replacement regime for AI. In special situations such as sickness, operations, pregnancy and drug interactions, cautious HC dosing or the correct choice of glucocorticoids is necessary. From long-term treatment, optimal diurnal rhythm and concentration of serum cortisol are important for the prevention of cardiovascular disease and osteoporosis. In maintenance therapy during the growth period of patients with 21-hydroxylase deficiency, proper doses of HC should be used, and long-acting glucocorticoids should not be used. Education and carrying an emergency card are essential for the prevention and rapid treatment of adrenal crisis.

PIASy mediates hypoxia-induced SIRT1 transcriptional repression and epithelial-to-mesenchymal transition in ovarian cancer cells.

Epithelial-mesenchymal transition (EMT) has an essential role in organogenesis and contributes to a host of pathologies, including carcinogenesis. Hypoxia (low oxygen supply) aids tumor metastasis in part by promoting EMT in cancer cells. The underlying mechanism whereby hypoxia orchestrates EMT remains poorly defined. Here we report that SIRT1, a multifaceted player in tumorigenesis, opposed ovarian cancer metastasis in vitro and in vivo by impeding EMT. Hypoxic stress downregulated the expression of SIRT1, primarily at the transcriptional level, by reducing the occupancy of the transcriptional activator Sp1 on the proximal promoter of the SIRT1 gene in a SUMOylation-dependent manner. Further analysis revealed that the SUMO E3 ligase PIASy (also known as PIAS4) was induced by hypoxia and prevented Sp1 from binding to the SIRT1 promoter. Conversely, knockdown of PIASy by small interfering RNA (siRNA) restored Sp1 binding and SIRT1 expression in cancer cells challenged with hypobaric hypoxia, reversed cancer cell EMT, and attenuated metastasis in vivo in nude mice. Importantly, analysis of human ovarian tumor specimens indicated that PIASy expression was positively, whereas SIRT1 expression was inversely, correlated with cancer aggressiveness. In summary, our work has identified a new pathway that links downregulation of SIRT1 to hypoxia-induced EMT in ovarian cancer cells and, as such, sheds light on the development of novel anti-tumor therapeutics.

Interaction of pituitary hormones and expression of clock genes modulated by bone morphogenetic protein-4 and melatonin.

Functional interaction of clock genes and pituitary hormones was investigated by focusing on bone morphogenetic protein (BMP)-4 and melatonin actions in anterior pituitary cells. A significant correlation between the mRNA expression of proopiomelanocortin (POMC) and Per2 was revealed in serial cultures of corticotrope AtT20 cells. Knockdown of Per2 expression by siRNA in AtT20 cells resulted in a significant reduction of POMC mRNA level with or without corticotropin-releasing hormone (CRH) stimulation. Treatments with BMP-4 and melatonin, both of which suppress POMC expression, reduced Per2 mRNA as well as protein levels in AtT20 cells. On the other hand, in lactosomatotrope GH3 cells, an expressional correlation was found between prolactin (PRL) and Clock mRNA levels, which was attenuated in the presence of forskolin treatment. The siRNA-mediated knockdown of Clock expression, but not that of Bmal1, significantly reduced PRL mRNA levels in GH3 cells. Interestingly, Clock mRNA and protein levels did not fluctuate with melatonin, BMP-4 or forskolin treatment, although Bmal1 expression was significantly increased by forskolin treatment. Collectively, a significant correlation between the expression of POMC and Per2 and that between PRL and Clock were uncovered in corticotrope and lactosomatotrope cells, respectively. Per2 expression was inhibited by POMC modulators including melatonin and BMP-4, while Clock expression was steadily maintained. Thus, the effects of melatonin and BMP-4 on clock gene expression may imply differential stability of circadian rhythms of adrenocorticotropin (ACTH) and PRL secreted from the anterior pituitary.

Histone deacetylase inhibition attenuates transcriptional activity of mineralocorticoid receptor through its acetylation and prevents development of hypertension.

RATIONALE: Inhibition of histone deacetylases (HDACs) results in attenuated development of hypertension in deoxycorticosterone acetate-induced hypertensive rats and spontaneously hypertensive rats. However, the molecular mechanism remains elusive. OBJECTIVE: We hypothesized that HDAC inhibition attenuates transcriptional activity of mineralocorticoid receptor (MR) through its acetylation and prevents development of hypertension in deoxycorticosterone acetate-induced hypertensive rats. METHODS AND RESULTS: Expression of MR target genes was measured by quantitative real-time polymerase chain reaction. Recruitment of MR and RNA polymerase II on promoters of target genes was analyzed by chromatin immunoprecipitation assay. Live cell imaging was performed for visualization of nuclear translocation of MR. MR acetylation was determined by Western blot with anti-acetyl-lysine antibody after immunoprecipitation with anti-MR antibody. Transcriptional activity of MR was determined by luciferase assay. For establishment of a hyperaldosteronism animal, Sprague-Dawley rats underwent uninephrectomy and received subcutaneous injection of 40 mg/kg per week of deoxycorticosterone acetate and drinking water containing 1% NaCl. Treatment with a HDAC class I inhibitor resulted in reduced expression of MR target genes in accordance with reduced recruitment of MR and RNA polymerase II on promoters of target genes. HDAC inhibition promoted MR acetylation, leading to decreased transcriptional activity of MR. Knockdown or inhibition of HDAC3 resulted in reduced expression of MR target genes induced by mineralocorticoids. CONCLUSIONS: These results indicate that HDAC inhibition attenuates transcriptional activity of MR through its acetylation and prevents development of hypertension in deoxycorticosterone acetate-induced hypertensive rats.

A novel loss-of-function mutation of GATA3 (p.R299Q) in a Japanese family with Hypoparathyroidism, Deafness, and Renal Dysplasia (HDR) syndrome.

BACKGROUND: Hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is a rare autosomal dominant disorder caused by mutations in the zinc finger transcription factor gene, GATA3. GATA3 has 2 zinc finger domains, which play an important role in the increase in target gene transcription activity. CASE PRESENTATION: A 50-year-old woman and her 27-year-old daughter were followed up because of hypoparathyroidism. They had bilateral sensorineural deafness. Abdominal computed tomography scanning revealed renal dysplasia in the mother, but no renal anomaly in the daughter. Direct sequencing of GATA3 gene revealed a novel heterozygous missense mutation at codon 299 (p.R299Q) in exon 4. This mutation is located at the junction between the 2 zinc fingers. The structure prediction showed that it caused a conformation change in this junction area, affecting the spatial position of the zinc fingers. Additionally, a more marked conformation change was observed in the N-terminal zinc finger region compared to that in the C-terminal region. Functional analysis of this mutant protein using an in vitro luciferase reporter assay system confirmed that the mutation abolished the enhancing effects of wild-type GATA3 on the promoter activity of the consensus GATA responsive element and that of human PTH gene. CONCLUSION: We identified a novel R299Q mutation in GATA3 in a Japanese family with HDR syndrome. We confirmed that R299Q is a loss-of-function mutation, due to the extensive conformational change in the zinc fingers of GATA3.

Inhibitory effects of trichostatin A on adrenocorticotropic hormone production and proliferation of corticotroph tumor AtT-20 cells.

Cushing's disease is primarily caused by adrenocorticotropic hormone (ACTH)-producing pituitary adenomas. Pituitary tumor-transforming gene 1 (PTTG1) expression, a hallmark of pituitary tumors, stimulates pituitary cell proliferation. Histone deacetylases (HDACs) play an important role in regulating gene transcription and HDAC inhibitors induce cellular differentiation and suppress tumor cell proliferation. HDAC inhibitors also repress PTTG1 mRNA levels. Trichostatin A (TSA) is a potent cell-permeable HDAC inhibitor that blocks cell cycle progression. In the present study, we determined the effect of TSA on ACTH production and cellular proliferation in mouse AtT-20 corticotroph tumor cells. TSA decreased proopiomelanocortin (POMC) mRNA levels in AtT-20 cells and reduced ACTH levels in the culture medium of these cells. The TSA-induced decreases in POMC mRNA levels were not modulated when TSA and dexamethasone were simultaneously administered. Drug treatment also decreased AtT-20 cell proliferation, induced apoptosis, and increased the percentage of cells in G0/G1 phase using flow cytometry. TSA decreased PTTG1 mRNA levels. Furthermore, PTTG1 knockdown inhibited cellular proliferation. Its knockdown also inhibited POMC mRNA and ACTH levels. TSA inhibits ACTH production and corticotroph tumor cell proliferation. TSA may inhibit cellular proliferation, and ACTH synthesis and secretion by decreasing PTTG1 expression.

Influence of clinical experience of the Macintosh laryngoscope on performance with the Pentax-AWS Airway Scope(®), a rigid video-laryngoscope, by paramedics in Japan.

PURPOSE: We sought to establish the clinical utility of the Pentax-AWS Airway Scope(®) (AWS) when used by paramedics to intubate the trachea, and to evaluate whether their performance was influenced by previous clinical experience with the Macintosh laryngoscope (ML). METHODS: Twenty paramedics attempted tracheal intubation using the AWS in five patients each in the operating room. We recorded the success rate, the number of intubation attempts, and the time for intubation and adverse events, and compared these based on the paramedics' previous clinical experience with the ML. Ten paramedics had no prior clinical experience of the ML (group A) and 10 had used it on more than 30 occasions (group B). RESULTS: The intubation success rate was 99 % (99/100). Notably, 96 % (47/49) of intubations were achieved on the first attempt by the inexperienced paramedics in group A, compared with 64 % (32/50) by the experienced paramedics in group B (p = 0.0001). The time to intubation (mean ± SD) was significantly shorter in group A than in group B (37 ± 24 vs. 48 ± 21 s, p = 0.002). There were marked variations in the times taken to intubate, but no apparent improvement as the intubators gained experience between their first and fifth cases. No complications were encountered in either group. CONCLUSION: We found that paramedics could achieve a high tracheal intubation success rate using the AWS independent of previous airway management experience. Better intubation performance with the AWS was observed in paramedics without clinical experience with the ML.

Retinoic acid receptor-α up-regulates proopiomelanocortin gene expression in AtT20 corticotroph cells.

Cushing's disease is a disorder caused by excessive ACTH secretion from a corticotroph tumor of the pituitary gland. Although its standard therapy is a transsphenoidal surgery, innovation of novel medical treatments for the disease is urgently necessary. Retinoic acid (RA) has been reported to suppress adrenocorticotropic hormone (ACTH) secretion in Cushing's disease. However, the role of RA receptor (RAR) in proopiomelanocortin (Pomc) gene expression remains uncertain. We here examined the involvement of RARα in Pomc regulation using AtT20 corticotroph cells. Surprisingly, a synthetic RARα agonist Am80 increased Pomc mRNA expression, CRH-induced ACTH secretion, and Pomc promoter activity. Small interfering RNA-mediated RARα-knockdown suppressed both basal and Am80-induced Pomc promoter activity. RARα-overexpression dose-dependently increased Pomc promoter activity. Pomc promoter mutation analysis revealed that both Tpit and NeuroD1 binding elements were responsible for the Am80-mediated effect. Am80 increased Tpit expression while RAR antagonist LE540 suppressed the increase. Tpit-overexpression increased Pomc promoter activity. Mammalian two-hybrid assay revealed that Am80 induced NeuroD1-RARα interaction. NeuroD1-overexpression enhanced the Am80-induced Pomc promoter activity, which was suppressed by NeuroD1 truncated mutant-overexpression. RARα thus positively regulates ACTH secretion/Pomc gene expression through interaction with NeuroD1 and Tpit expression increase. The present observation will be useful for the future development of the RA/retinoid-derived therapeutics of the disease.

Prognosis of primary aldosteronism in Japan: results from a nationwide epidemiological study.

The Research Committee of Disorders of Adrenal Hormones, Japan, undertook a nationwide epidemiological study of primary aldosteronism (PA). The present study was undertaken as a part of this study to reveal the relationship between type of treatment and the prognosis of PA. In the primary survey, 4161 patients with PA during the period January 1, 2003-December 31, 2007 were reported from 3252 departments of internal medicine, pediatrics and urology. In the secondary survey, a questionnaire that requested detailed clinical information on individual patients was sent to those departments reporting patients in the primary survey. In total, data on 1706 patients with PA were available in the present study. Among patients with bilateral or unilateral aldosterone-producing adenoma, after adjustment for age at which prognosis was examined, sex, surgical treatment and medical treatment, surgical treatment was significantly associated with amelioration of hypertension (adjusted odds ratio [OR]: 0.47 [95% confidence interval (CI): 0.29-0.77]) and hypokalemia (adjusted OR: 0.17 [95% CI: 0.11-0.29]). No significant relationship was observed between medical treatment and such prognosis in this group of patients. Among patients with bilateral or unilateral adrenal hyperplasia, surgical, but not medical, treatment was significantly associated with amelioration of hypokalemia (adjusted OR: 0.23 [95% CI: 0.06-0.74]), while there was no relationship between surgical or medical treatment and the prognosis of hypertension. In conclusion, surgery offered a better prognosis of PA than medication with regards to hypertension and hypokalemia, with the limitation that a new anti-aldosterone drug, eplerenone, was not available during the study period.

Interferon gamma (IFN-γ) disrupts energy expenditure and metabolic homeostasis by suppressing SIRT1 transcription.

Chronic inflammation impairs metabolic homeostasis and is intimately correlated with the pathogenesis of type 2 diabetes. The pro-inflammatory cytokine IFN-γ is an integral part of the metabolic inflammation circuit and contributes significantly to metabolic dysfunction. The underlying mechanism, however, remains largely unknown. In the present study, we report that IFN-γ disrupts the expression of genes key to cellular metabolism and energy expenditure by repressing the expression and activity of SIRT1 at the transcription level. Further analysis reveals that IFN-γ requires class II transactivator (CIITA) to repress SIRT1 transcription. CIITA, once induced by IFN-γ, is recruited to the SIRT1 promoter by hypermethylated in cancer 1 (HIC1) and promotes down-regulation of SIRT1 transcription via active deacetylation of core histones surrounding the SIRT1 proximal promoter. Silencing CIITA or HIC1 restores SIRT1 activity and expression of metabolic genes in skeletal muscle cells challenged with IFN-γ. Therefore, our data delineate an IFN-γ/HIC1/CIITA axis that contributes to metabolic dysfunction by suppressing SIRT1 transcription in skeletal muscle cells and as such shed new light on the development of novel therapeutic strategies against type 2 diabetes.

Prospective multicenter study of the epidemiological features of emergency patients with overdose of over-the-counter drugs in Japan.

Aim: To investigate the epidemiological characteristics of patients presenting to the emergency department with an overdose of over-the-counter (OTC) drugs. Methods: A questionnaire survey was conducted to examine the sociodemographic characteristics of patients with OTC drugs overdoses visiting emergency departments at eight sites across the country. The patients were divided into "habitual" and "nonhabitual" groups according to their history of OTC drugs overdose. Student's t-test or Welch's t-test was performed for numerical variables, and Pearson's χ 2 test was performed for dichotomous and nominal variables between the two groups. Results: Of the 124 patients included in this study, 79% were women. The habitual (26.6%) and the nonhabitual (73.4%) groups showed no differences in sex, occupation, cohabitants, history of mental illness, or history of alcohol consumption or smoking; however, those in the habitual group were significantly younger. The proportion of OTC drugs obtained from physical stores was higher in the habitual group, whereas the nonhabitual group used more household medicines. Suicide and self-harm were more common reasons for overdose in the nonhabitual group. Antipyretic analgesics were significantly more common in the nonhabitual group, whereas antitussive expectorants and antihistamines were significantly more common in the habitual group. Conclusion: This is the first multicenter study to determine the status of OTC drugs overdose patients treated at emergency departments of medical facilities in Japan. To prevent new overdoses of OTC drugs, continued detailed epidemiologic studies of patient backgrounds and drug acquisition routes, and investigation of the components of OTC drugs that cause dependency are necessary.

Snail modulates cell metabolism in MDCK cells.

Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP(+)-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of key enzymes. This results in enhanced glucose dependency and leads to cell death under low-glucose conditions. On the other hand, the reduced requirements for oxygen and nutrients from the surrounding environment, might confer the resistance to cell death induced by hypoxia and malnutrition.

Growth differentiation factor-15 stimulates the synthesis of corticotropin-releasing factor in hypothalamic 4B cells.

Growth differentiation factor-15 (GDF15) is a stress-activated cytokine that regulates cell growth and inflammatory and stress responses. We previously reported the role and regulation of GDF15 in pituitary corticotrophs. Dexamethasone increases Gdf15 gene expression levels and production. GDF15 suppresses adrenocorticotropic hormone synthesis in pituitary corticotrophs and subsequently mediates the negative feedback effect of glucocorticoids. Here, we analyzed corticotropin-releasing factor (Crf) promoter activity in hypothalamic 4B cells transfected with promoter-driven luciferase reporter constructs. The effects of time and GDF15 concentration on Crf mRNA levels were analyzed using quantitative real-time polymerase chain reaction. Glial cell-derived neurotrophic factor family receptor α-like (GFRAL) protein is expressed in 4B cells. GDF15 increased Crf promoter activity and Crf mRNA levels in 4B cells. The protein kinase A and C pathways also contributed to the GDF15-induced increase in Crf gene expression. GDF15 stimulates GFRAL, subsequently increasing the phosphorylation of AKT, an extracellular signal-related kinase, and the cAMP response element-binding protein. Therefore, GDF15-dependent pathways may be involved in regulating Crf expression under stressful conditions in hypothalamic cells.

The Impact of Multicultural Interfacility Video Case Conference: A Novel Education Model After the COVID Pandemic.

Context: The COVID-19 pandemic challenged undertaking gradual educational activities for residency and fellowship trainees. However, recent technological advances have enabled broadening active learning opportunities through international online conferences. Objective: The format of our international online endocrine case conference, launched during the pandemic, is introduced. The objective impact of this program on trainees is described. Methods: Four academic facilities developed a semiannual international collaborative endocrinology case conference. Experts were invited as commentators to facilitate in-depth discussion. Six conferences were held between 2020 and 2022. After the fourth and sixth conferences, anonymous multiple-choice online surveys were administered to all attendees. Results: Participants included trainees and faculty. At each conference, 3 to 5 cases of rare endocrine diseases from up to 4 institutions were presented, mainly by trainees. Sixty-two percent of attendees reported 4 facilities as the appropriate size for the collaboration to maintain active learning in case conferences. Eighty-two percent of attendees preferred a semiannual conference. The survey also revealed the positive impact on trainees' learning regarding diversity of medical practice, academic career development, and confidence in honing of presentation skills. Conclusion: We present an example of our successful virtual global case conference to enhance learning about rare endocrine cases. For the success of the collaborative case conference, we suggest smaller cross-country institutional collaborations. Preferably, they would be international, semiannually based, and with recognized experts as commentators. Since our conference has engendered multiple positive effects on trainees and faculty, continuation of virtual education should be considered even after the pandemic era.