Retinoic acid receptor agonists regulate expression of ATP-binding cassette transporter G1 in macrophages.

ABC transporter G1 (ABCG1) plays a pivotal role in HDL-mediated cholesterol efflux and atherogenesis. We investigated whether, and how, retinoic acid receptors (RARs) regulate ABCG1 expression in macrophages. All-trans retinoic acid (ATRA), an RAR ligand, increased ABCG1 protein levels and apoA-I/HDL-mediated cholesterol efflux from the macrophages. Both ATRA and other RAR agonists, TTNPB and Am580, increased major transcripts driven by promoter B upstream of exon 5, though minor transcripts driven by promoter A upstream of exon 1 were only increased by ATRA. The stimulatory effects of ATRA on ABCG1 expression were completely abolished in the presence of RAR/RXR antagonists but were only partially canceled in the presence of an LXR antagonist. Adenovirus with overexpressed oxysterol sulfotransferase abolished the LXR pathway, as previously reported, and ATRA-responsiveness in ABCA1/ABCG1 expressions were respectively attenuated by 38 and 22% compared to the control virus. Promoter assays revealed that ABCG1 levels were regulated more by promoter B than promoter A, and ATRA activated promoter B in a liver X receptor-responsive element (LXRE)-dependent manner. Further, LXRE-B in intron 7, but not LXRE-A in intron 5, enhanced ATRA responsiveness under overexpression of all RAR isoforms-RARα/ß/γ. In contrast, the activation of promoter B by TTNPB depended on LXRE-B and RARα, but not on RARß/γ. Finally, chromatin immunoprecipitation and gel-shift assays revealed a specific and direct repeat 4-dependent binding of RARα to LXRE-B. In conclusion, RAR ligands increase ABCA1/G1 expression and apoA-I/HDL-mediated cholesterol efflux from macrophages, and modulate ABCG1 promoter activity via LXRE-dependent mechanisms.

Coffee consumption enhances high-density lipoprotein-mediated cholesterol efflux in macrophages.

RATIONALE: Association of habitual coffee consumption with coronary heart disease morbidity and mortality has not been established. We hypothesized that coffee may enhance reverse cholesterol transport (RCT) as the antiatherogenic properties of high-density lipoprotein (HDL). OBJECTIVE: This study was to investigate whether the phenolic acids of coffee and coffee regulates RCT from macrophages in vitro, ex vivo and in vivo. METHODS AND RESULTS: Caffeic acid and ferulic acid, the major phenolic acids of coffee, enhanced cholesterol efflux from THP-1 macrophages mediated by HDL, but not apoA-I. Furthermore, these phenolic acids increased both the mRNA and protein levels of ATP-binding cassette transporter (ABC)G1 and scavenger receptor class B type I (SR-BI), but not ABCA1. Eight healthy volunteers were recruited for the ex vivo study, and blood samples were taken before and 30 minutes after consumption of coffee or water in a crossover study. The mRNA as well as protein levels of ABCG1, SR-BI, and cholesterol efflux by HDL were increased in the macrophages differentiated under autologous sera obtained after coffee consumption compared to baseline sera. Finally, effects of coffee and phenolic acid on in vivo RCT were assessed by intraperitoneally injecting [(3)H]cholesterol-labeled acetyl low-density lipoprotein-loaded RAW264.7 cells into mice, then monitoring appearance of (3)H tracer in plasma, liver, and feces. Supporting in vitro and ex vivo data, ferulic acid was found to significantly increase the levels of (3)H tracer in feces. CONCLUSIONS: Coffee intake might have an antiatherogenic property by increasing ABCG1 and SR-BI expression and enhancing HDL-mediated cholesterol efflux from the macrophages via its plasma phenolic acids.

Proteasomal inhibition promotes ATP-binding cassette transporter A1 (ABCA1) and ABCG1 expression and cholesterol efflux from macrophages in vitro and in vivo.

OBJECTIVE: ATP-binding cassette transporter A1 (ABCA1) and ABCG1 are key molecules in an initial step of reverse cholesterol transport (RCT), a major antiatherogenic property of high-density lipoprotein (HDL). The ubiquitin-proteasome system (UPS) mediates nonlysosomal pathways for protein degradation and is known to be involved in atherosclerosis. However, little is known about the effects of the UPS on these molecules and overall RCT. We therefore investigated whether UPS inhibition affects ABCA1/G1 expression in macrophages and RCT in vitro and in vivo. METHODS AND RESULTS: Various proteasome inhibitors increased ABCA1/G1 expression in macrophages, translating into enhanced apolipoprotein A-I- and HDL-mediated cholesterol efflux from macrophages. ABCA1 and ABCG1 were found to undergo polyubiquitination in the macrophages and HEK293 cells overexpressing these proteins, and pulse-chase analysis revealed that proteasome inhibitors inhibited ABCA1/G1 protein degradation. In in vivo experiments, the proteasome inhibitor bortezomib increased ABCA1/G1 protein levels in mouse peritoneal macrophages, and RCT assays showed that it significantly increased the fecal (54% increase compared with saline) and plasma (23%) appearances of the tracer derived from intraperitoneally injected (3)H-cholesterol-labeled macrophages. CONCLUSIONS: The present study provided evidence that the UPS is involved in ABCA1/G1 degradation, thereby affecting RCT in vivo. Therefore, specific inhibition of the UPS pathway might lead to a novel HDL therapy that enhances RCT.

Vasospasm-induced ST-segment elevation myocardial infarction in a premenopausal woman with endothelial dysfunction.

ST-segment elevation myocardial infarction (STEMI) can be caused by coronary artery vasospasm (VSA) due to endothelial dysfunction. However, the clinical role of endothelial function tests in VSA-induced STEMI is not fully understood. We present the case of a 43-year-old woman with atypical chest pain and no coronary risk factors. STEMI caused by VSA was diagnosed. Flow-mediated vasodilatation (FMD) and EndPAT tests were performed; the FMD and reactive hyperaemia index were 3.8% and 1.23, respectively. Endothelial dysfunction is the putative cause of STEMI. FMD and EndPAT tests might be useful for predicting adverse outcomes in young premenopausal women with VSA.

Delayed Vasovagal Reaction with Reflex Syncope Following COVID-19 Vaccination.

Coronavirus disease 2019 (COVID-19) has become a pandemic, and vaccines remain the only effective tools available for ending it. However, their side effects, such as syncope, which mimics sudden cardiac death, are serious concerns. We herein report 6 cases of delayed vasovagal syncope and presyncope (VVR) caused by COVID-19 vaccination among 25,530 COVID-19 patients. The prevalence of delayed VVR due to COVID-19 vaccination was 0.026%. In addition, no delayed VVR was found among 17,386 patients who received the influenza vaccine. Delayed VVR is likely to be overlooked if medical staff are not aware of this symptom. This report provides significant information regarding effects of COVID-19 vaccination.

Decadal electrocardiographic changes between age 40 and 50 in military pilots.

INTRODUCTION: Cardiovascular diseases can lead to sudden in-flight incapacitation and long-term disability in aircraft pilots. Electrocardiogram (ECG) has been widely used to screen for these diseases in routine aeromedical examinations. Several ECG changes such as complete left bundle-branch block (CLBBB) and left ventricular hypertrophy (LVH) have been associated with increased likelihood of underlying structural cardiac diseases in addition to the emergence of newly recognized cardiovascular diseases such as Brugada syndrome. Therefore, the purpose of this study was to analyze decadal ECG changes in aircraft pilots between 40 and 50 yr in order to make an appropriate evaluation of these ECG changes. METHODS: We analyzed the ECGs from the annual aeromedical examination of age 50 compared to those 40 yr of age in a total of 176 Japan Air Self-Defense Force pilots. RESULTS: With regard to decadal changes, we detected 34 new ECG changes (1 of sinus tachycardia, 8 sinus bradycardia, 1 atrial fibrillation, 2 premature atrial contraction, 1 premature ventricular contraction, 2 left axis deviation, 6 first-degree atrioventricular block, 1 CLBBB, 3 complete right bundle-branch block, 2 incomplete right bundle-branch block, 1 right ventricular conduction delay, and 6 LVH). Although the majority of them were concluded to be normal variants, the results of echocardiography in two hypertensive pilots without good control demonstrated abnormalities: one had mild hypertrophic nonobstructive cardiomyopathy and another had heart enlargement. CONCLUSION: Thus, this study recommends additional cardiovascular examinations, including echocardiography for hypertensive pilots with ECG changes.

Ventricular fibrillation diagnosed during electrophysiological study for non-sustained tachycardia.

Ventricular fibrillation diagnoses such as Brugada syndrome pose a risk of sudden incapacitation or death in aircrew. This case report presents a 44-yr-old male fighter pilot who unexpectedly developed ventricular fibrillation (VF) during an electrophysiological study (EPS) prior to therapy for non-sustained ventricular tachycardia (nsVT). The initial aeromedical disposition for this case was "qualified for flying duties". with the restriction that he must fly with another pilot due to repeatedly observed nsVT. This pilot wanted to return to flight duty in single-seat aircraft without any restrictions. Therefore, this patient decided to undergo catheter therapy for nsVT. Unexpectedly, not VT but VF was induced by catheter manipulation during EPS. Pilsicainide-induced coved-type ST wave elevation consistent with Brugada syndrome was noted in this patient's electrocardiogram. He was ultimately disqualified due to the diagnosis of VF. This report suggests EPS on rare occasions may uncover another severe disease similar to this case report.

COVID-19 in older adults: Retrospective cohort study in a tertiary hospital in Japan.

AIM: We aimed to describe the clinical characteristics, treatment and outcomes of patients with COVID-19 pneumonia, in particular older patients, admitted to tertiary and partner hospitals in Saitama, Japan. METHODS: We retrospectively reviewed the medical records of patients with COVID-19 pneumonia admitted to tertiary and partner hospitals in Saitama, Japan. Twenty-six patients with COVID-19 were categorized into two groups, i.e., older (≥75 years) and younger adults (≤74 years). We evaluated the clinical characteristics, comorbidities, symptoms, laboratory test results, treatments and outcomes of the patients. RESULTS: The majority of the older patients had comorbidities, such as dementia, cardiovascular disease and bone fractures. Comorbidities were significantly more frequent in older patients than younger patients. No association was found between age and body temperature or the incidence of respiratory failure. White blood cell count was significantly lower in older patients (P = 0.018) and the decrease in lymphocytes was greater in younger patients (P = 0.009). Computed tomography (CT) of all patients showed non-segmental, peripherally dominant ground-glass opacities consistent with COVID-19 pneumonia. In older patients, antiviral drugs, anticoagulants and anti-inflammatory drugs were administered on a compassionate use basis. The difference in mortality between the older and the younger patients was not statistically significant. CONCLUSIONS: In older patients, typical clinical symptoms and blood test changes were often absent; however, CT always contained typical findings of COVID-19, suggesting that CT may be a useful diagnostic tool. Our report illustrates that appropriate treatment, taking patient background into consideration, may improve their condition regardless of age. Geriatr Gerontol Int 2020; 20: 1044-1049.

Waivers for cardiovascular diseases in military aircrew: differences between Japanese and U.S. protocols.

INTRODUCTION: Cardiovascular diseases can cause sudden incapacitation in aircrew. Cardiological diagnosis and therapy have changed a great deal in recent decades, as with coronary revascularization, including percutaneous coronary intervention and coronary artery bypass grafting for coronary artery disease, and electrophysiological studies and radiofrequency catheter ablation (RFCA) for sustained arrhythmias. Physicians need to be able to make appropriate, objective recommendations regarding cardiovascular diseases in an aeromedical waiver system. METHODS: We analyzed all 95 waiver cases regarding cardiovascular diseases in the Japan Air Self-Defense Force (JASDF), 1980-2007, and compared them to policies in the United States Air Force (USAF). RESULTS: The JASDF and the USAF handle most conditions similarly, although there are differences regarding coronary revascularization, atrial fibrillation, non-sustained ventricular tachycardia (nsVT), and hypertrophic cardiomyopathy. The JASDF used RFCA more commonly for the treatment of aircrew with atrial fibrillation and nsVT Although routine follow-up with electrophysiological studies is no longer indicated for Wolff-Parkinson-White and atrioventricular node reentrant tachycardia in USAF policy, the JASDF still conducts reevaluation for all RFCA cases. CONCLUSION: This study made recommendations to improve the JASDF waiver system for cardiovascular diseases.

Survey of severe spatial disorientation episodes in Japan Air Self-Defense Force fighter pilots showing increased severity in night flight.

Spatial disorientation (SD) is one of the most severe causative factors in aviation accidents. We analyzed the reported SD episodes to evaluate the characteristics of severe SD in fighter pilots. Three hundred seventeen cases (95.5%) of 332 total valid cases experienced SD, and the ratio of night and day SD experiences (52.7% vs. 47.3%) (p < 0.05) shows a clear prevalence of night SD events. The severity of SD episodes at night (2.23 +/- 1.09) was higher than at day (1.89 +/- 1.04) (p < 0.01). In addition, the severity of visual illusions was significantly higher at night. A significant difference was found for meteorological conditions, such as visual meteorological conditions (VMC), instrument meteorological conditions (IMC) and VMC-IMC (VI) transition, among times of days. In conclusion, the severity of the SD episodes was higher at night. This may be due to an increase in visual severe SD episodes at night.

Telmisartan enhances cholesterol efflux from THP-1 macrophages by activating PPARgamma.

AIM: The ATP binding cassette transporters A1 and G1 (ABCA1/G1) and scavenger receptor class B type I (SR-BI) are key molecules in cholesterol efflux and atherogenesis. These genes are regulated by peroxisome proliferator-activated receptor gamma (PPARgamma) and liver X receptor (LXR). Telmisartan is an angiotensin type 1 receptor blocker which has been reported to act as a ligand for PPARgamma. We investigated whether PPARgamma-activating ARBs affect the expression of these genes and cholesterol efflux from macrophages. METHODS AND RESULTS: Telmisartan increased ABCA1, ABCG1 and SR-BI mRNA levels in THP-1 macrophages in a dose- and time-dependent fashion. It also increased their protein levels and enhanced apoA-I- and HDL-mediated cholesterol efflux from macrophages. The knockdown of PPARgamma by siRNA abolished the telmisartan-induced expression of these genes. The knockdown of LXRalpha resulted in the complete and partial abolishment of telmisartan-induced ABCA1 and ABCG1 expression, respectively. We also demonstrated that telmisartan-induced SR-BI expression was dependent on the PPARgamma pathway but not on the LXRalpha pathway. A luciferase assay using an ABCA1 promoter construct showed that telmisartan activated ABCA1 transcription, which was abolished if the LXR binding element was mutated, indicating that increased ABCA1 transcription by telmisartan is LXR-dependent. CONCLUSION: Our results showed that telmisartan enhanced both apoA-I- and HDL-mediated cholesterol efflux from macrophages by increasing ABCA1, ABCG1 and SR-BI expression via PPARgamma-dependent and LXR-dependent/independent pathways.

[A Japanese case of melioidosis presenting as multiple organ lesions accompanied by sepsis and disseminated intravascular coagulation, after a visit to Thailand].

A 65-year-old man with diabetes mellitus reporting fever and urination disturbance on a flight from Bangkok back to Japan in July 2003 was admitted elsewhere for acute prostatitis. Despite intravenous antibiotics, his condition deteriorated. On admission to our hospital, he suffered from respiratory failure, with laboratory data showing disseminated intravascular coagulation (DIC). Computed tomography (CT) shows infiltrative and nodular shadows in both lung fields and low-density areas in the left kidney and prostate gland, consistent with pneumonia and abscesses in these organs. He also developed broad osteomyelitis in the right lower extremity with cellulitis and arthritis in the right hand, knee, and foot. Blood, urine, and joint fluid culture all yielded Burkholderia pseudomallei, so he was diagnosed with melioidosis. Treatment was started with meropenem and minocycline, then meropenem was changed to imipenem. His symptoms gradually improved after ciprofloxacin was added, so all intravenous antibiotics were discontinued and he underwent oral treatment with chloramphenicol, minocycline, and sulfamethoxazole/trimethoprim in September 2003. He developed fever again, however, and oral therapy was discontinued and intravenous antibiotics restarted. After resolution of fever, oral maintenance therapy was initiated again with levofloxacin and minocycline in October, and his condition remained stable. After discharge in April 2004, he has been followed up with no evidence of relapse. This is considered to be the seventh case of melioidosis reported in Japan. Our patient manifested multiple organ lesions with sepsis and DIC, and was difficult to treat, but clinical symptoms improved in long-term antibiotic administration. With travelers to Southeast Asia increasing, greater attention must be paid to imported infectious diseases, such as melioidosis.

[A case of small cell lung cancer under hemodialysis with chronic renal failure treated with amrubicin while measuring blood concentration of the drug].

We reported a case of small cell lung cancer treated with amrubicin while receiving hemodialysis. An 83-year-old man with chronic renal failure being treated by hemodialysis was admitted because of a left hilar mass. Small cell lung cancer with liver metastasis (cT2NOM1) was diagnosed. Two courses of chemotherapy with amrubicin resulted in partial response. Toxicity was relatively mild. We measured blood concentration of amrubicin during the first course of chemotherapy. There was no significant difference in blood cell and plasma concentration of amrubicin hydrochloride and amrubicinol between days when he received hemodialysis and when he did not receive hemodialysis. Thus, we considered that amrubicin hydrochloride may be a good candidate for the treatment of small cell lung cancer patients with chronic renal failure under hemodialysis.

Disseminated Cryptococcosis with Rapidly Growing Lung Nodules in an End-stage Renal Disease Patient.

A 73-year-old man with type 2 diabetes mellitus and end-stage renal disease was diagnosed with acute myocardial infarction. He required continuous dialysis after percutaneous coronary intervention. Subsequently, multiple nodules were discovered in both lungs for the first time, and Cryptococcus neoformans was isolated from the patient's sputum, blood, bilateral pleural fluid, and cerebrospinal fluid cultures, resulting in a diagnosis of disseminated cryptococcosis. This case represents an invaluable example of disseminated cryptococcosis with rapidly growing lung nodules in a dialysis patient, and illustrates that dialysis causes innate immune disorder and the reactivation of cryptococcosis.

Arrhythmias observed during high-G training: proposed training safety criterion.

INTRODUCTION: Most arrhythmias during centrifuge training are physiological responses to high +Gz stress. However, potentially dangerous arrhythmias occasionally occur during centrifuge training. We reviewed all arrhythmias recorded during the Japan Air Self-Defense Force (JASDF) centrifuge training from April 2001 to March 2003, and developed a criterion for suspending G-training based on observed arrhythmias. METHOD: There were 195 male fighter pilots who received high-G centrifuge training monitored with electrocardiographs (ECGs). We evaluated types and occurrences of all arrhythmias during high-G training over a 24-mo period. RESULTS: Sinus arrhythmia (48.7%), single premature atrial contraction (32.3%), and single (58.5%) or paired (9.7%) premature ventricular contraction were commonly occurring arrhythmias during high-G training. We considered these arrhythmias as variant physiological responses to high-G training (category 1). In addition, we observed ventricular tachycardia (2.6%), paroxysmal supraventricular tachycardia (1.5%), and paroxysmal atrial fibrillation (0.5%). Further investigation of these trainees revealed a significant proportion with cardiac anomalies. As a result, the JASDF currently categorizes these arrhythmias as indicators to suspend G-training and initiate cardiac workup (category 3). Other arrhythmias, such as non-sustained ventricular tachycardia (VT) or Morbitz type I atrioventricular (AV) block, were considered borderline anomalies; whether training was allowed to continue depended on the decision of the physicians monitoring the training (category 2). CONCLUSION: Routine ECG monitoring during centrifuge training is recommended to catch the pathology underlying dangerous arrhythmias for flight safety. Our proposed criterion for stopping the centrifuge is intended to differentiate between serious arrhythmias and arrhythmias of physiologic response.

[An autopsy case of pulmonary and central nervous system metastatic osteosarcoma treated with thirty-six courses of chemotherapy over four years].

A 32-year-old man presented with cough, dyspnea and orthopnea ten years after amputation of the right humerus because of osteosarcoma. Chest radiographs and chest computed tomographs showed left pleural effusion, pericardial effusion and a giant intrathoracic mass, which was histologically diagnosed as a recurrence of the osteosarcoma. After 4 courses of chemotherapy combined with CDDP, the mass in the left upper lobe of the lung decreased in size, and it was then resected. Three months later, new metastatic lesions were detected in the thoracic area. Therefore, 29 additional courses of chemotherapy were administered (36 courses in total over 4 years; including regimens combined with CDDP, carboplatin, high-dose methotrexate, ifosfamide, dacarbazine, vindesine, etoposide, vincristine, taxotere and gemcitabine). In spite of the several courses of chemotherapy, brain and spinal cord metastases appeared, and the patient eventually died of cerebral hemorrhage. During the four years after the first recurrence he had good quality of life as a result of the chemotherapy.

Astaxanthin enhances ATP-binding cassette transporter A1/G1 expressions and cholesterol efflux from macrophages.

ATP-binding cassette transporters (ABC) A1 and G1 are key molecules in cholesterol efflux from macrophages, which is an initial step of reverse cholesterol transport (RCT), a major anti-atherogenic property of high-density lipoprotein (HDL). Astaxanthin is one of the naturally occurring carotenoids responsible for the pink-red pigmentation in a variety of living organisms. Although astaxanthin is known to be a strong antioxidant, it remains unclear through what mechanism of action it affects cholesterol homeostasis in macrophages. We therefore investigated the effects of astaxanthin on cholesterol efflux and ABCA1/G1 expressions in macrophages. Astaxanthin enhanced both apolipoprotein (apo) A-I- and HDL-mediated cholesterol efflux from RAW264.7 cells. In supporting these enhanced cholesterol efflux mechanisms, astaxanthin promoted ABCA1/G1 expression in various macrophages. In contrast, peroxisome proliferator-activated receptor γ, liver X receptor (LXR) α and LXRß levels remained unchanged by astaxanthin. An experiment using actinomycin D demonstrated that astaxanthin transcriptionally induced ABCA1/G1 expression, and oxysterol depletion caused by overexpression of cholesterol sulfotransferase further revealed that these inductions in ABCA1/G1 were independent of LXR-mediated pathways. Finally, we performed luciferase assays using human ABCA1/G1 promoter-reporter constructs to reveal that astaxanthin activated both promoters irrespective of the presence or absence of LXR-responsive elements, indicating LXR-independence of these activations. In conclusion, astaxanthin increased ABCA1/G1 expression, thereby enhancing apoA-I/HDL-mediated cholesterol efflux from the macrophages in an LXR-independent manner. In addition to the anti-oxidative properties, the potential cardioprotective properties of astaxanthin might therefore be associated with an enhanced anti-atherogenic function of HDL.

Statin inhibits hypoxia-induced endothelin-1 via accelerated degradation of HIF-1α in vascular smooth muscle cells.

AIMS: Endothelin-1 (ET-1) contributes to the pathogenesis of cardiovascular diseases with multiple properties such as vasoconstriction. Human ET-1 gene expression is up-regulated by the transcription factor hypoxia-inducible factor-1 (HIF-1) through hypoxia response element (HRE). Although previous studies suggested that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) alter HIF-1-related gene expression, it remained unclear whether statins modulate HIF-1-mediated ET-1 expression. Therefore, we investigated the effect of fluvastatin on hypoxia-induced human ET-1 expression in vascular smooth muscle cells (VSMC). METHODS AND RESULTS: Hypoxia (1% O(2)), compared with the normoxic condition (21% O(2)), significantly induced the expression of preproET-1 mRNA, ET-1 protein, and ET-1 secretion in VSMC. Hypoxia induced a 2.3-fold increase in HRE-dependent ET-1 reporter gene activation. Under concentrations of 1 µmol/L or greater, fluvastatin attenuated the hypoxia-induced ET-1 gene expression through the accelerated ubiquitin/proteasome-dependent degradation of HIF-1α, thus consequently attenuating HIF-1α binding to the HRE of the ET-1 gene. These inhibitory effects of fluvastatin were cancelled by concomitant treatment with mevalonate, farnesyl pyrophosphate, or geranylgeranyl pyrophosphate, but not squalene. CONCLUSION: The present study suggests that fluvastatin attenuates HIF-1-dependent ET-1 gene expression in conjunction with the stimulation of HIF-1α ubiquitin/proteasome-dependent degradation via isoprenoid-dependent mechanisms.