Single-Cell RNA Sequencing Reveals an Immune Landscape of CD4+ T Cells in Coronary Culprit Plaques With Acute Coronary Syndrome in Humans-Brief Report.

BACKGROUND: Acute coronary syndrome (ACS) involves plaque-related thrombosis, causing primary ischemic cardiomyopathy or lethal arrhythmia. We previously demonstrated a unique immune landscape of myeloid cells in the culprit plaques causing ACS by using single-cell RNA sequencing. Here, we aimed to characterize T cells in a single-cell level, assess clonal expansion of T cells, and find a therapeutic target to prevent ACS. METHODS: We obtained the culprit lesion plaques from 4 patients with chronic coronary syndrome (chronic coronary syndrome plaques) and the culprit lesion plaques from 3 patients with ACS (ACS plaques) who were candidates for percutaneous coronary intervention with directional coronary atherectomy. Live CD45+ immune cells were sorted from each pooled plaque samples and applied to the 10× platform for single-cell RNA sequencing analysis. We also extracted RNA from other 3 ACS plaque samples and conducted unbiased TCR (T-cell receptor) repertoire analysis. RESULTS: CD4+ T cells were divided into 5 distinct clusters: effector, naive, cytotoxic, CCR7+ (C-C chemokine receptor type 7) central memory, and FOXP3 (forkhead box P3)+ regulatory CD4+ T cells. The proportion of central memory CD4+ T cells was higher in the ACS plaques. Correspondingly, dendritic cells also tended to express more HLAs (human leukocyte antigens) and costimulatory molecules in the ACS plaques. The velocity analysis suggested the differentiation flow from central memory CD4+ T cells into effector CD4+ T cells and that from naive CD4+ T cells into central memory CD4+ T cells in the ACS plaques, which were not observed in the chronic coronary syndrome plaques. The bulk repertoire analysis revealed clonal expansion of TCRs in each patient with ACS and suggested that several peptides in the ACS plaques work as antigens and induced clonal expansion of CD4+ T cells. CONCLUSIONS: For the first time, we revealed single cell-level characteristics of CD4+ T cells in patients with ACS. CD4+ T cells could be therapeutic targets of ACS. REGISTRATION: URL: https://upload.umin.ac.jp/cgi-open-bin/icdr_e/ctr_view.cgi?recptno=R000046521; Unique identifier: UMIN000040747.

Acute Coronary Syndrome Due to Intraplaque Hemorrhage in a Post-gastrectomy Patient with a Latent Severe Glycemic Disorder.

Glycemic disorders involving large glucose fluctuations and recurrent hypoglycemia may lead to adverse cardiovascular events, including acute coronary syndrome (ACS). Flash glucose monitoring (FGM) has reportedly been useful for detecting latent glycemic disorders. However, only a few studies have so far reported latent glycemic disorders in coronary artery disease. Thus, we herein present a unique case of ACS due to intraplaque hemorrhage in a post-gastrectomy patient who had no apparent coronary risk, except for a latent severe glycemic disorder detected via FGM. This masked etiology should be considered in ACS patients who have no apparent cardiovascular risks in order to improve their cardiovascular outcomes.

Structural differences in bacterial lipopolysaccharides determine atherosclerotic plaque progression by regulating the accumulation of neutrophils.

BACKGROUND AND AIMS: Gut microbial lipopolysaccharide (LPS) induces endotoxemia, an independent risk factor for cardiovascular disease (CVD). However, no studies have demonstrated how structural differences in each bacterial LPS contribute to endotoxemia. Here, we investigated the effects of different acyl chains in the lipid A moiety of LPS on endotoxemia and the subsequent immune response and atherosclerotic plaque formation. METHODS: Apoe-/- mice were intraperitoneally administered 2 mg/kg of Escherichia coli-derived LPS (E. LPS, as a representative of hexa-acylated lipid A), Bacteroides-derived LPS (B. LPS, as a representative of penta- or tetra-acylated lipid A), or saline (control) once a week, six times. An immunohistological assessment was performed on plaque sections. RESULTS: E. LPS administration induced endotoxemia, but B. LPS and saline did not. In E. LPS-treated mice, total plaque areas in the aortic root were significantly increased, and neutrophil accumulation and increased formation of neutrophil extracellular traps (NETs) were observed at the plaque lesions, but not in B. LPS-treated mice. A single dose of E. LPS significantly increased the accumulation of neutrophils in plaque lesions on day 3, and NET formation on day 7. E. LPS also increased interleukin-1 beta (IL-1ß) production in plaque lesions on day 7. Furthermore, NET formation and IL-1ß production were also observed in human coronary plaques. CONCLUSIONS: We identified a previously unknown link between structural differences in LPS and atherosclerosis. Lowering microbial LPS activity may reduce NET formation in plaques and prevent CVD progression.

Histopathological findings of late-phase restenosis after directional coronary atherectomy with drug-coated balloon angioplasty: a case report.

Background: Drug-coated balloon angioplasty after directional coronary atherectomy (DCA) allows for a stentless strategy providing good short-term outcomes; however, late-phase restenosis and its mechanism remain unclear. Moreover, histopathological evaluation for late-phase restenosis post-drug-coated balloon angioplasty after DCA has never been reported. Case summary: We report the first case of late-phase restenosis post-drug-coated balloon angioplasty after DCA, wherein tissue analysis using intravascular coronary imaging and histopathology suggested neovascularization in newly developed neointimal proliferation. A 52-year-old man with a history of dyslipidaemia presented with exertional angina pectoris. He underwent percutaneous coronary intervention (PCI) with drug-coated balloon angioplasty after DCA for the proximal left anterior descending artery. Although coronary angiography after nine months revealed no restenosis, he experienced recurrent chest discomfort after 25 months. Coronary angiography confirmed late-phase restenosis, and intravascular ultrasound showed progressively developed neointima above the underlying residual plaque. Optical coherence tomography suggested developing neovascularization within the neointima. Stentless PCI with drug-coated balloon angioplasty after DCA was re-performed, and collected restenotic sample. The histopathological evaluation confirmed less-cellular neointimal proliferation with rich neovascularization and concomitant diffuse vascular endothelial growth factor (VEGF) expression. Discussion: Late-phase restenosis post-drug-coated balloon angioplasty after DCA comprised less-cellular neointima, suggesting inhibition of cell proliferation by drug-coated balloon efficacy. However, diffuse VEGF expression and concomitant rich neovascularization with haemorrhage and inflammation might indicate neointimal proliferation. Further large-scale investigations of the restenotic mechanism should be performed to avoid long-term target vascular failure after drug-coated balloon angioplasty post-DCA.

Brachial-ankle pulse wave velocity in healthy Japanese adolescents: reference values for the assessment of arterial stiffness and cardiovascular risk profiles.

Brachial-ankle pulse wave velocity (baPWV) has been used as a simple and convenient method of evaluating arterial stiffness and is considered useful for screening subclinical vascular damage in primary care settings and in large populations. The aim of this study was to determine the reference values of baPWV in adolescents based on age and sex to evaluate and classify vascular abnormalities in this age population. Noninvasive baPWV measurements using an oscillometric device were carried out in 5936 participants aged 12-18 years who had no history of syndromic obesity, hypertension, dyslipidemia, diabetes mellitus, or renal disease. Of these, we extracted data from 4524 healthy adolescents free from atherosclerotic risk factors and constructed sex-specific reference percentiles normalized to age using the LMS method. The baPWV increased with age and was significantly higher in males than in females. Multivariate regression analysis demonstrated that age, body mass index, and blood pressure were the major determinants of baPWV for both males and females. Among a sample of 3825 adolescents, including individuals with risk factors, the prevalence of central obesity, raised blood pressure, raised triglycerides, reduced high-density lipoprotein cholesterol, and impaired fasting glycemia significantly increased along with the standardized baPWV z-score level. In addition, there was a graded nature regarding the association between the baPWV z-score and the clustering number of the metabolic syndrome components. These results suggest that the proposed reference values of baPWV could help classify vascular abnormalities of adolescents caused by the presence of risk factors and thereby contribute to determining individuals with cardiovascular risk in this age population.

The combination of obesity and high salt intake are associated with blood pressure elevation among healthy Japanese adolescents.

We examined the associations of obesity and high salt intake with blood pressure (BP) in a cross-sectional sample of 1679 healthy Japanese adolescents (827 females and 852 males) aged 12-18 years (mean age: 14.9 years) who had no history of treatment for hypertension, diabetes mellitus, or renal disease. Brachial arterial BP of the subject was measured at the left arm using a digital BP monitor with an appropriate cuff size. The weight status was evaluated by body mass index (BMI), and obesity was determined according to the age- and sex-specific cut-off values for adolescents. All subjects were interviewed by dietitians using a food frequency questionnaire to obtain data on their average daily salt intake. In the study subjects, obesity and high salt intake were associated with a significantly increased BP except for diastolic BP in females. In multiple regression analyses, both BMI (z-score) and salt intake were found to be major determinants of systolic BP and diastolic BP after adjustment for potential confounders, including age, sex, and serum lipid and glucose parameters. The association between salt intake and BP values was more pronounced among individuals with obesity than among those with normal weight. These results suggest that high salt intake is associated with BP elevation in healthy adolescents, and the association may become stronger by the presence or severity of obesity.

Outcomes of knee arthrodesis following infected total knee arthroplasty: a retrospective analysis of 8 cases.

BACKGROUND: There is insufficient information regarding patient-based outcomes after knee arthrodesis following infected total knee arthroplasty (TKA). The purpose of this study was to analyze outcomes in patients who underwent knee arthrodesis following infected TKA using clinical and radiographic measurements including a patient-based outcome measuring system. METHODS: We evaluated 8 patients (mean age 72.9 years) who were followed for more than 3 years after arthrodesis. Clinical and radiographic evaluation was performed, including examination of the patient's function and use of supportive equipment for walking. The Japanese knee osteoarthritis measurement (JKOM) was used for measuring patient-based outcomes and health-related quality of life. RESULT: Knee fusion was achieved in 7 patients. The mean limb-length discrepancy was 5.4 cm. All patients could walk at least inside the house, and activity of daily living (ADL) independence was achieved by the patients with successful knee fusion, although walking aids, including a shoe lift causing little discomfort, were required. The results of JKOM for the patients with successful fusion were comparable to the data for patients who underwent TKA. CONCLUSIONS: When knee arthrodesis was performed for infected TKA cases, pain was reduced and ADL independence was established when knee fusion was achieved. This study demonstrated that information from subjective and functional evaluations of knee arthrodesis patients is useful in understanding postoperative activity and situations, and revealed the importance of supportive elements for walking.

Outcomes of knee arthrodesis following infected total knee arthroplasty: a retrospective analysis of 8 cases.

BACKGROUND: There is insufficient information regarding patient-based outcomes after knee arthrodesis following infected total knee arthroplasty (TKA). The purpose of this study was to analyze outcomes in patients who underwent knee arthrodesis following infected TKA using clinical and radiographic measurements including a patient-based outcome measuring system. METHODS: We evaluated 8 patients (mean age 72.9 years) who were followed for more than 3 years after arthrodesis. Clinical and radiographic evaluation was performed, including examination of the patient's function and use of supportive equipment for walking. The Japanese knee osteoarthritis measurement (JKOM) was used for measuring patient-based outcomes and health-related quality of life. RESULT: Knee fusion was achieved in 7 patients. The mean limb-length discrepancy was 5.4 cm. All patients could walk at least inside the house, and activity of daily living (ADL) independence was achieved by the patients with successful knee fusion, although walking aids, including a shoe lift causing little discomfort, were required. The results of JKOM for the patients with successful fusion were comparable to the data for patients who underwent TKA. CONCLUSIONS: When knee arthrodesis was performed for infected TKA cases, pain was reduced and ADL independence was established when knee fusion was achieved. This study demonstrated that information from subjective and functional evaluations of knee arthrodesis patients is useful in understanding postoperative activity and situations, and revealed the importance of supportive elements for walking.

Age-specific nomogram of brachial-ankle pulse wave velocity in Japanese adolescents.

To obtain data on the brachial-ankle pulse wave velocity (baPWV) distribution during adolescence, a total of 3215 Japanese adolescents ranging from 12 to 18 years of age were studied. The brachial-ankle pulse wave velocity increased substantially with age and was significantly higher in males than in females. Multivariate regression analysis revealed that age, weight, and systolic and diastolic blood pressures were the major determinants of baPWV for both genders. Age-specific centile curves of baPWV were constructed for males and females by regression curve analysis. The proposed distribution curves of baPWV and its derived cutoff values may allow the atherosclerotic risk profile among adolescents of different ages to be more precisely estimated.

Arthroscopic resection of multiple ossifying tumors in the infrapatellar fat pad.

A 49 year-old male visited a nearby clinic five years back with a complaint of pain in the right knee during exercise. Plain radiographs revealed absence of any anomalies. He began to feel a lumpy mass in his right knee two years back. The pain worsened, on imaging, an anomaly was identified in the infrapatellar fat pad of his right knee, and he was subsequently referred to our department where he was hospitalized. On examination, a mass extending on either side of the patellar tendon was identified along with rigid tenderness in that area. The knee's range of motion was 0degrees-130degrees, and knee flexion was accompanied by pain. The results of blood tests were normal. A plain radiograph of the knee revealed multiple ossifying tumors at a site consistent with the infrapatellar fat pad. T1-weighted MRI exhibited low-signal intensity, while T2-weighted MRI exhibited a mosaic-shaped tumor. We performed arthroscopic surgery to excise the tumor. The patient resumed work shortly after surgery and did not experience any pain during the two year postoperative observation period. The joint's range of motion improved to the extent that it was comparable with that of the left knee. No recurrence was observed on radiographic examination. In past studies, resection of similar tumors has been performed with an arthrotomy; however, we performed arthroscopic resection on our patient, who demonstrated a quick improvement in symptoms and range of motion after surgery. We believe that arthroscopic surgery is a feasible option to consider while treating such cases.

LKB1 is crucial for TRAIL-mediated apoptosis induction in osteosarcoma.

BACKGROUND: Despite improvements in chemotherapy and surgery in the treatment of osteosarcoma, satisfactory results are still difficult to achieve. New therapeutic modalities need to be developed for the improvement of these treatments. TRAIL (TNF-related apoptosis inducing ligand) is known as a selective apoptosis inducer in most tumor cells, but not in normal cells. Therefore, TRAIL is a good candidate target for the treatment of tumors. However, sensitivity of osteosarcoma cells to TRAIL-induced apoptosis is lower than that of other types of tumor cells. Recently, DAP3 (death associated protein 3) was demonstrated to play a critical role in TRAIL-mediated apoptosis through activation of pro-caspase-8. Here, we found that LKB1, a serine/threonine kinase, expressed in bone and soft tissue sarcoma cells, associated with DAP3. We also demonstrated that expression of DAP3 induced apoptosis in osteosarcoma cells. Furthermore, expression of LKB1 induced apoptosis and co-expression of LKB1 with DAP3 strongly induced apoptosis in osteosarcoma cells. In addition, expression of LKB1 kinase dead mutant, LKB1 (K78M), inhibited DAP3-induced apoptosis in these cells. These results suggest that LKB1 is critical for TRAIL-induced apoptosis induction, cooperating with DAP3 in osteosarcoma cells. It is predicted that LKB1 and DAP3 could be critical target molecules for the treatment of osteosarcomas.

Ambulatory blood pressure, sympathetic activity, and left ventricular structure and function in middle-aged normotensive men with exaggerated blood pressure response to exercise.

BACKGROUND: It is claimed that exaggerated blood pressure (BP) reactivity to behavioral stress may play a role in hypertension. This study aimed to clarify whether exaggerated BP reactivity during physical exercise is associated with any other abnormalities in ambulatory BP, autonomic nervous control, and target organ damage among middle-aged normotensive men. MATERIAL/METHODS: A total of 54 sedentary men (39+/-4 years old) with normal BP were enrolled in this study. Twenty-seven with exaggerated BP reactivity to exercise (ER) were compared with 27 age-matched controls with normal BP reactivity (NR). The subjects underwent 24-hour ambulatory BP monitoring, short-term Finapres recordings, a bicycle ergometry test, and M-mode and pulsed-Doppler echocardiography. RESULTS: The ambulatory BP measurements were significantly higher in the ER group than in the NR group averaged over a 24-hour period, during daytime and nighttime. Power spectral analysis from continuous Finapres data revealed increased systolic BP variability in the low frequency band in the ER group. During graded exercise, the ER group showed remarkable elevations in systolic and diastolic BP compared to the NR group without a difference in heart rate increments. Although the plasma epinephrine showed similar levels, yet the exercise-induced increase in plasma norepinephrine in the ER group was significantly greater than in the NR group. In echocardiographic dimensions, left ventricular internal diameter and mass index were not different, whereas the ER group presented significantly greater posterior wall thickness. Doppler functional data showed significant increase in the late to early flow velocity ratio in the ER group. CONCLUSIONS: Even in the absence of hypertension, exaggerated BP reactivity to physical exercise suggests greater BP elevation during daily activity as well as enhanced sympathetic nervous tonus, which may be considered a risk factor promoting hypertension, and these hemodynamic and neurohumoral behaviors are associated with a tendency to develop target organ abnormalities in the heart.

Serum leptin levels in healthy adolescents: Effects of gender and growth.

OBJECTIVES: The purposes of this paper were to evaluate the serum leptin levels in healthy adolescents and to establish standard age variation curves. METHODS: Nine hundred six (414 boys and 492 girls) healthy adolescents were investigated. The maximum increment age in height (MIA) was identified in 124 boys and 130 girls. The menarcheal age (MA) was obtained for 130 girls. Fasting leptin levels were measured by enzyme immunoassay. The MIA was calculated by proportional allotment of yearly height increments. RESULTS: Serum leptin levels did not change in boys and girls from the ages of 9 to 11. They decreased after the age of 11 in boys, while they increased in girls. Stepwise multiple regression analysis revealed that serum leptin levels were closely related to pubertal stage. The levels decreased remarkably after MIA in boys and increased remarkably after MA in girls. We drew standard age variation curves of serum leptin levels by calculating the 25th, 50th and 75th percentiles for each age in both boys and girls. The percentile curves for boys were divided into pre-MIA and post-MIA curves. Those for girls were divided into pre-MA and post-MA curves. CONCLUSION: We have devised a potentially useful method for evaluating serum leptin levels in adolescents considering the effects of gender and growth.

Antihypertensive effects of aerobic exercise in middle-aged normotensive men with exaggerated blood pressure response to exercise.

An exaggerated blood pressure (BP) response to physical exertion among normotensive subjects is considered a significant risk factor for future hypertension. The purpose of this study was to examine whether regular aerobic exercise can lead to a reduction in hypertensive risks in patients with such a high-risk profile. Thirty-five sedentary men (46 +/- 2 years old) with normal BP at rest but an exaggerated BP response during exercise were randomly assigned to an exercise or control group for 12 weeks followed by an 8-week washout period. The subjects were then crossed over to the alternate group for an additional 12-week period. The exercise training consisted of 3 days per week of stationary bicycling for 45 min at 50-60% of the heart rate reserve. The treatment effects were evaluated using the method of Hills and Armitage. The training-induced reduction in resting BP was not statistically significant. In ambulatory BP monitoring, the averages of 24-h and daytime systolic and diastolic BP were significantly lower, but nighttime BP remained unchanged after training. During ergometric exercise, significant decreases were observed in systolic and diastolic BP and plasma norepinephrine concentration measured at the submaximal workloads. M-mode echocardiographic and Doppler-derived left ventricular variables were not significantly affected by training. These findings suggest that regular aerobic exercise attenuates BP elevations during physical exertion and daytime activities mainly as a result of the reduction in enhanced sympathetic nervous tonus, which may in turn play a role in lowering the risk for hypertension in normotensive subjects with an exaggerated BP response to exercise.