Kenji Ashida

Mechanism of action of anti-aging DHEA-S and the replacement of DHEA-S

The plasma ACTH and cortisol levels do not change during aging. On the other hand, the plasma dehydroepiandrosterone sulfate (DHEA-S) changes remarkably during aging. Before puberty, the plasma DHEA-S level both in males and females is very low, however, it rapidly increases at puberty, and thereafter significantly decreases both linearly and age-dependently. Cytochrome P450c17 has two enzyme activities, 17-alpha-hydroxylase and 17,20-lyase. Cortisol is synthesized by 17-alpha-hydroxylase, and DHEA is synthesized by 17,20-lyase. The mechanism of dissociation of cortisol and DHEA synthesis in aging depends on another regulator of 17,20-lyase of cytochrome P450c17 such as cytochrome P450 reductase. We demonstrated significant decrease in cytochrome P450 reductase activity in bovine aged adrenal glands. We clarified the beneficial effects of DHEA as an anti-aging steroid based on both in vitro and in vivo experiments, such as the stimulatory effect of immune system, anti-diabetes mellitus, anti-atherosclerosis, anti-dementia (neurosteroid), anti-obesity and anti-osteoporosis. It is very important to identify the mechanism of action of DHEA. We clarified the conversion of DHEA to estrone by cytochrome P450 aromatase in primary cultured human osteoblasts. We indentified high affinity of DHEA binding with K(d)=6.6 nM in antigen and DHEA stimulated human T lymphocytes. We searched for the target genes that are specifically induced in activated T lymphocytes in the presence of DHEA by subtractive hybridization screening for differentially expressed transcripts. The double blind, randomized human replacement therapies utilizing DHEA are also reviewed.

Abolition of Torsade de Pointes after radiofrequency catheter ablation at right ventricular outflow tract

Radiofrequency (RF) catheter ablation was tried to treat a patient with syncope, perhaps due to polymorphic ventricular tachycardia (VT) of Torsade de Pointes (TdP) type which was documented by Holter monitoring. Electrophysiological study showed that the isolated ventricular extrasystoles (VEs) that initiated TdP were exactly replicated by pace mapping at the septal site of the right ventricular outflow tract. Performance of RF ablation at this site abolished the TdP and episodes of syncope with no requirement for antiarrhythmic agents for 3 years, whereas isolated VEs persisted. Although it is difficult to mention whether RF ablation was successful or not in this case, this procedure should be considered as a potentially curative approach to the TdP, when the arrhythmogenic focus can be fixed and identified as in this case.

Isolated ACTH deficiency probably induced by autoimmune-related mechanism evoked with nivolumab

Nivolumab, an anti-programmed death-1 antibody, is a breakthrough treatment for several malignancies. Its specific adverse effects caused by autoimmunity are termed immune-related adverse events, which involve several endocrine dysfunctions. Herein, we report two cases of isolated adrenocorticotropic hormone (ACTH) deficiency induced by nivolumab for the treatment of metastatic malignant melanoma. Case 1 was a 39-year-old man and Case 2 was a 50-year-old woman, both of whom presented with progressive melanoma. After 13 courses of nivolumab administration, both cases were diagnosed with adrenal insufficiency. Despite their basal serum ACTH and cortisol levels being low with little response to corticotropin-releasing hormone loading, other anterior pituitary hormone levels were preserved. Based on these endocrinological data, isolated ACTH deficiency was diagnosed. Magnetic resonance imaging showed normal pituitary glands, excluding hypophysitis. Finally, hydrocortisone replacement enabled the patients to continue nivolumab treatment. Therefore, it is important to consider isolated ACTH syndrome as a possible and potentially severe immune-related adverse event of nivolumab, even when head magnetic resonance imaging of affected cases does not show enlargement. We should not misdiagnose hidden immune-related adverse events behind general complaints of malignancies such as general malaise and appetite loss, to allow successful treatment using this beneficial immune checkpoint inhibitor.

Activin type IB receptor signaling in prostate cancer cells promotes lymph node metastasis in a xenograft model

Activin, a member of the transforming growth factor-β family, has been known to be a growth and differentiating factor. Despite its pluripotent effects, the roles of activin signaling in prostate cancer pathogenesis are still unclear. In this study, we established several cell lines that express a constitutive active form of activin type IB receptor (ActRIBCA) in human prostate cancer cells, ALVA41 (ALVA-ActRIBCA). There was no apparent change in the proliferation of ALVA-ActRIBCA cells in vitro; however, their migratory ability was significantly enhanced. In a xenograft model, histological analysis revealed that the expression of Snail, a cell-adhesion-suppressing transcription factor, was dramatically increased in ALVA-ActRIBCA tumors, indicating epithelial mesenchymal transition (EMT). Finally, mice bearing ALVA-ActRIBCA cells developed multiple lymph node metastases. In this study, we demonstrated that ActRIBCA signaling can promote cell migration in prostate cancer cells via a network of signaling molecules that work together to trigger the process of EMT, and thereby aid in the aggressiveness and progression of prostate cancers.

HMGA1a induces alternative splicing of estrogen receptor alpha in MCF-7 human breast cancer cells

The high-mobility group A protein 1a (HMGA1a) protein is known as an oncogene whose expression level in cancer tissue correlates with the malignant potential, and known as a component of senescence-related structures connecting it to tumor suppressor networks in fibroblasts. HMGA1 protein binds to DNA, but recent studies have shown it exerts novel functions through RNA-binding. Our previous studies have shown that sequence-specific RNA-binding of HMGA1a induces exon-skipping of Presenilin-2 exon 5 in sporadic Alzheimer disease. Here we show that HMGA1a induced exon-skipping of the estrogen receptor alpha (ERα) gene and increased ERα46 mRNA expression in MCF-7 breast cancer cells. An RNA-decoy of HMGA1a efficiently blocked this event and reduced ERα46 protein expression. Blockage of HMGA1a RNA-binding property consequently induced cell growth through reduced ERα46 expression in MCF-7 cells and increased sensitivity to tamoxifen in the tamoxifen-resistant cell line, MCF-7/TAMR1. Stable expression of an HMGA1a RNA-decoy in MCF-7 cells exhibited decreased ERα46 protein expression and increased estrogen-dependent tumor growth when these cells were implanted in nude mice. These results show HMGA1a is involved in alternative splicing of the ERα gene and related to estrogen-related growth as well as tamoxifen sensitivity in MCF-7 breast cancer cells.

Sex hormone and neuroendocrine aspects of the metabolic syndrome.

We discuss the recent advances in the knowledge that the sex steroids testosterone (T), estradiol and dehydroepiandrosterone sulphate (DHEA-S) are involved in the development of visceral obesity and of the metabolic syndrome. Cross talk between leptin and the androgen receptor (AR) in the hypothalamus as well as the peripheral conversion of DHEA and T to estrone, estradiol and dihydrotestosterone (DHT) in adipocytes and hepatocytes play important roles in the metabolic syndrome in men. Finally, we discuss the development of new drugs, selective AR modulators, for treating the metabolic syndrome in men.

HMGA1a Induces Alternative Splicing of the Estrogen Receptor-αlpha Gene by Trapping U1 snRNP to an Upstream Pseudo-5′ Splice Site

Objectives: The high-mobility group A protein 1a (HMGA1a) protein is known as a transcription factor that binds to DNA, but recent studies have shown it exerts novel functions through RNA-binding. We were prompted to decipher the mechanism of HMGA1a-induced alternative splicing of the estrogen receptor alpha (ERα) that we recently reported would alter tamoxifen sensitivity in MCF-7 TAMR1 cells. Methods: Endogenous expression of full length ERα66 and its isoform ERα46 were evaluated in MCF-7 breast cancer cells by transient expression of HMGA1a and an RNA decoy (2′-O-methylated RNA of the HMGA1a RNA-binding site) that binds to HMGA1a. RNA-binding of HMGA1a was checked by RNA-EMSA. In vitro splicing assay was performed to check the direct involvement of HMGA1a in splicing regulation. RNA-EMSA assay in the presence of purified U1 snRNP was performed with psoralen UV crosslinking to check complex formation of HMGA1a-U1 snRNP at the upstream pseudo-5′ splice site of exon 1. Results: HMGA1a induced exon skipping of a shortened exon 1 of ERα in in vitro splicing assays that was blocked by the HMGA1a RNA decoy and sequence-specific RNA-binding was confirmed by RNA-EMSA. RNA-EMSA combined with psoralen UV crosslinking showed that HMGA1a trapped purified U1 snRNP at the upstream pseudo-5′ splice site. Conclusions: Regulation of ERα alternative splicing by an HMGA1a-trapped U1 snRNP complex at the upstream 5′ splice site of exon 1 offers novel insight on 5′ splice site regulation by U1 snRNP as well as a promising target in breast cancer therapy where alternative splicing of ERα is involved.

Correlation Between Lateralization Index of Adrenal Venous Sampling and Standardized Outcome in Primary Aldosteronism

Abstract Objectives The aim of this study was to investigate the impact of adrenal venous sampling (AVS) lateralization cutoffs on surgical outcomes. Patients and Methods Cosyntropin-stimulated AVS was used to guide surgical management of 377 patients with primary aldosteronism (PA) who were evaluated 6 months after surgery. Main Outcome Measures The proportion of patients that achieved clinical benefit and complete biochemical success based on the AVS aldosterone lateralization index (LI) was determined. Results Clinical benefit was achieved in 29 of 47 patients with an LI between 2 and 4, in 66 of 101 with an LI between 4 and 10, and in 158 of 203 with an LI > 10 (P < 0.01 for trend). Complete biochemical success was achieved in 27 of 42 with an LI between 2 and 4, in 60 of 76 with an LI between 4 and 10, and in 127 of 155 with an LI > 10 (P = 0.024 for trend). After adjustment for confounders and using those patients with an LI between 2 and 4 as a reference, a clinical benefit was associated only with those with an LI > 10 (OR, 2.30; 95% CI, 1.03 to 5.16), whereas complete biochemical success was associated with those with an LI between 4 and 10 (OR, 2.83; 95% CI, 1.14 to 7.01) or LI > 10 (OR, 3.55; 95% CI, 1.47 to 8.55). Conclusions Difference of clinical outcome was relatively small when strict LI diagnostic threshold was used; biochemical cure was sufficiently achieved when an LI > 4 was used. Our study by standardized outcome measures validated that an LI > 4 may be appropriate for determining unilateral disease in PA.

Change of Oral to Topical Corticosteroid Therapy Exacerbated Glucose Tolerance in a Patient with Plaque Psoriasis

Patient: Male, 80 Final Diagnosis: Plaque psoriasis• drug induced diabetes Symptoms: Hyperglycemia• adrenocortical dysfunction Medication: Oral steroid• Topical steroid• Insulin Clinical Procedure: Changing route and strength of steroid administration Specialty: Endocrinology• Dermatology Objective: Rare disease Background: Psoriasis is known as the most frequent disease treated by long-term topical steroids. It is also known that patients with thick, chronic plaques require the highest potency topical steroids. However, the treatment is limited to up to four weeks due to risk of systemic absorption. Case Report: An 80-year-old man was diagnosed with type 2 diabetes 16 years before, and was being administered insulin combined with alpha glucosidase inhibitor. He was diagnosed with plaque psoriasis and his oral steroid treatment was switched to topical steroid treatment due to lack of improvement and poorly controlled blood glucose level. The hypoglycemic events improved after the psoriatic lesions improved. Conclusions: Control of blood glucose level is difficult at the very beginning of topical steroid treatment for psoriasis especially if a patient is receiving insulin treatment. Intense monitoring of blood glucose level during initiation of topical steroid treatment is necessary to prevent unfavorable complications.

A case of ketoacidosis caused by the breakdown of the infusion syringe during continuous subcutaneous insulin infusion

IntroductionContinuous subcutaneous insulin injection (CSII) is an effective method for controlling blood glucose. However, complications include cutaneous complications (e.g., inflammation and infection) and uncontrollable blood glucose due to insulin leaks, obstruction, and technical problems, which may lead to hyperglycemia such as diabetic ketoacidosis (DKA) or hypoglycemia. However, other than islet or pancreas transplantation, CSII is the best method for controlling blood glucose.HistoryA patient with DKA using an old-type CSII instrument was referred to our hospital.InvestigationAt first, we could not understand why DKA had occurred because the skin at the infusion site appeared to be in good condition. However, the syringe was found to be broken when the instrument was unlocked and the pump was removed.ConclusionTo exchange older CSII instruments for newer models may be the safer alternative to prevent syringe accidents.