Association of secondhand smoke exposure and health-related lifestyle behaviors among male university employees in Japan.

Secondhand smoke (SHS) exposure causes various health problems associated with an unhealthy lifestyle. However, the lifestyles of individuals exposed to SHS have not been characterized extensively. Therefore, this cross-sectional study aimed to investigate the association between SHS exposure and lifestyle behaviors. The participants were 2379 healthy male employees at Osaka University who underwent health examinations. Physical and biochemical parameters and lifestyle behavior data were obtained from all the participants. Participants with SHS exposure had significantly higher body mass index, waist circumference, and serum levels of triglycerides and uric acid than that of those without SHS exposure. SHS exposure was significantly correlated with several lifestyle behaviors, including TV time, frequency of breakfast consumption and fried food consumption, vegetable and fruit intake, alcohol consumption frequency and daily alcohol intake, and smoking status. Thus, SHS exposure may be associated with an unhealthy lifestyle. The lifestyle behaviors of the smoke-excluded population were assessed further; however, SHS exposure was still associated with dietary and drinking habits. Since participants with SHS exposure are likely to have an unhealthy life and combined unhealthy lifestyle behaviors, the confounding effect of these factors should be considered when assessing the impact of SHS exposure on health.

Soluble angiotensin-converting enzyme 2 association with lipid metabolism.

Increased expression of angiotensin-converting enzyme 2 (ACE2) is one of the likely explanations for disease severity in patients with coronavirus disease 2019 (COVID-19). In this study, we aimed to test whether soluble ACE2 (sACE2) levels are correlated to known risk factors of severe COVID-19 including biochemical parameters, body mass index and smoking habits. We cross-sectionally evaluated serum sACE2 levels in obese or tobacco-smoking populations and compared them to those in non-obese and non-smoking healthy participants. Additionally, fibroblast growth factor-21 (FGF21) was investigated as a candidate regulator of sACE2. A total of 220 male participants aged 30-59 years undergoing an annual health checkup were enrolled in this study: 59 obese, 80 smokers, and 81 healthy. Serum sACE2 levels were significantly higher in obese participants but not in tobacco-smoking participants when compared to healthy participants. sACE2 levels were significantly correlated with total cholesterol and triglycerides but not with body mass index. Furthermore, no regulatory relationship was found between FGF21 and sACE2. Lipid metabolism disorders accompanied by upregulation of serum sACE2 may be underlying mechanisms of COVID-19 aggravation and might be a novel breakthrough treatment target.

Serum FGF21 levels are altered by various factors including lifestyle behaviors in male subjects.

Fibroblast growth factor (FGF) 21 has various functions, including glucose and lipid metabolism. This cross-sectional study aimed to investigate specific conditions that might influence the functions of FGF21. 398 men who underwent a health examination were enrolled in this study. Physical and biochemical parameters and information on several lifestyle behaviors were obtained from all subjects. FGF21 levels correlated with age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (γ-GTP), uric acid, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), fasting plasma glucose (FPG), and HbA1c. Moreover, FGF21 levels were significantly associated with lifestyle behaviors, including smoking status and breakfast and alcohol consumption frequency. Multivariable regression analysis showed that age, ALT, γ-GTP, smoking status, and breakfast and alcohol consumption frequency were independent variables for FGF21 levels. Assessment among the non-obese and obese groups showed that FGF21 levels correlated with WC, SBP, and TC only in the non-obese group. Thus, serum FGF21 levels were affected by several factors, including lifestyle behaviors, age, and liver function. To assess the functions of FGF21 in individuals, considering these factors would be essential.

Polycythemia Vera Associated with Pulmonary Hypertension and Diffuse Large B-Cell Lymphoma: A Case Report.

BACKGROUND Myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), are associated with pulmonary hypertension (PH) and malignant lymphomas. Although the underlying mechanisms have not been completely clarified, it has been suggested that the Janus kinase 2 (JAK2) mutation, which is frequently identified in PV, can be involved in the development and/or progression of these distinct diseases in patients with MPNs. However, no reports have described the coexistence of PH and malignant lymphoma in patients with MPNs. CASE REPORT A 79-year-old man being treated for PV for 27 years and PH for 5 years was hospitalized due to severe dyspnea at rest. His soluble interleukin-2 receptor levels gradually increased and the chest computed tomography showed remarkable progression of the lung lesions and an enlargement of the mediastinal and axillary lymph nodes. A lymph node biopsy was performed and the patient was diagnosed with diffuse large B-cell lymphoma (DLBCL). Owing to his poor condition, chemotherapy was not initiated, and he died on the 89th day of hospitalization. The pathological autopsy revealed the destruction of alveolar structures with neoplastic space-occupying lesions of DLBCL. Multifactorial features of PH associated with MPNs, including the intimal thickening of pulmonary arteries accompanied by megakaryocytes and obstructed pulmonary arteries with organized thrombi in the lung tissue specimens, were observed. We found a JAK2 mutation based on a genetic analysis of the patient's bone marrow. CONCLUSIONS We present the rare case of a patient who had PV with a JAK2 mutation, which coexisted with PH and DLBCL, and he developed severe refractory respiratory failure.

Long-term Effects of the Janus Kinase 1/2 Inhibitor Ruxolitinib on Pulmonary Hypertension and the Cardiac Function in a Patient with Myelofibrosis.

Constitutive activation of the Janus kinase/signal transduction and activator of transcription (JAK-STAT) signaling pathway plays a central role in the pathogenesis of myelofibrosis (MF) and pulmonary hypertension (PH) is a known complication of MF. On the other hand, it has been proposed that the JAK-STAT pathway, especially signal transducer and activation of transcription (STAT) 3 activation, protects cardiomyocytes from various stresses. We describe the case of a patient with MF-associated PH who developed left ventricular dysfunction after five years of treatment with the JAK 1/2 inhibitor, ruxolitinib. This is the first report with histopathological findings that demonstrate possible contradictory effects of a JAK 1/2 inhibitor: improvement of MF-associated PH and cardiotoxicity.

Implication of alpha-Klotho as the predictive factor of stress.

Stress is known as a risk factor for both mental and physical health problems. While stress is known as one of the major health problems in modern society, a biomarker of stress has not yet been well established. In the present study, we focused on the serum levels of α-Klotho (αKl) as a possible objective biomarker of stress. Subjects included apparently healthy individuals who underwent a health examination in the Osaka University Health and Counseling Center. Physical and biochemical parameters were obtained from all subjects. Information regarding the lifestyle of each individual was obtained via questionnaires. Among male subjects, serum levels of soluble αKl (sαKl) were significantly elevated in subjects who had poor stress management and unsatisfactory sleep, suggesting that stress management and sleeping conditions influenced the serum levels of sαKl. The total Kessler Screening Scale for Psychological Distress (K6) score was significantly increased in subjects who reported experiencing considerable stress, had poor stress management and unsatisfactory sleep. Since serum levels of sαKl showed the same tendency as the K6 score in terms of the relationship between stress management and sleeping conditions in male subjects, increased sαKl levels could be associated with considerable psychological stress in healthy men.

Successful treatment of severe combined post- and pre-capillary pulmonary hypertension in a patient with idiopathic restrictive cardiomyopathy.

Restrictive cardiomyopathy (RCM) is a rare form of cardiomyopathy that is characterized by restrictive ventricular filling. Elevated filling pressure leads to pulmonary hypertension (PH), which often progresses to combined post- and pre-capillary PH (Cpc-PH) with increased diastolic pulmonary vascular pressure gradient (DPG) and pulmonary vascular resistance (PVR) caused by longstanding backward hemodynamic consequences of left heart disease (LHD) leading to morphological changes in the pulmonary vasculature. Patients with high PVR undergoing left ventricular assist device (LVAD) implantation are at increased risk of postoperative right-sided heart failure requiring concomitant implantation of a right ventricular assist device (RVAD). We report a case of RCM with severe Cpc-PH due to extremely elevated DPG and PVR. The patient presented recurrent syncope caused by severe PH. Right heart catheterization (RHC) revealed highly elevated DPG 30 mmHg and PVR 25.3 Wood units (WU) and subsequent significant reduction of right ventricular afterload during vasoreactivity testing with inhaled nitric oxide (NO) to DPG 5 mmHg and PVR 10.5 WU. During the administration of pulmonary vasodilators, pulmonary congestion worsened. Second RHC revealed elevated pulmonary arterial wedge pressure (PAWP) and modest decrease of pulmonary arterial pressure (PAP) 87 mmHg and PVR 9.6 WU. Therefore, an inotropic agent and systemic vasodilator were added for the treatment of left-sided heart failure. Targeting elevated filling pressures with both PAH-specific and heart failure treatment, a further decrease of right ventricular afterload with DPG of 5 mmHg and PVR of 3.8 WU was achieved. In a next step, LVAD was successfully implanted, without need for RVAD, as a bridge to transplantation. This is the first reported case of Cpc-PH that revealed the potential reversibility of extremely elevated DPG and PVR, and suggests the importance of preoperative RHC-guided optimized medical PAH-specific and heart failure treatment before LVAD implantation.

An implication of Klotho-related molecules in different smoking-related health outcomes between men and women.

BACKGROUND: Men and women react differently to some disease states, and women are reported to be more sensitive than men to the toxic effects of smoking. We examined the serum concentration of Klotho-related molecules, α-Klotho (αKl) and fibroblast growth factor (FGF)-21, and the influence of smoking on these molecules in both sexes. METHODS: Subjects included 90 men and 140 women in good health who underwent a health examination. RESULTS: Among male subjects, serum concentrations of FGF-21, soluble sαKl, and inflammation-related cytokine interleukin (IL)-6 were significantly higher in smokers than in never-smokers. In females, serum concentrations of FGF-21 and IL-6 were significantly higher in smokers than in never-smokers; however, sαKl concentrations were slightly lower in smokers than in never-smokers. Serum concentrations of sαKl were correlated with smoking status and IL-6 only in male subjects, suggesting an anti-inflammatory effect of sαKl only in men. Serum concentrations of FGF-21 were correlated with the concentrations of total cholesterol, triglycerides, and HbA1c, which are important factors of metabolic disorders in females, suggesting that metabolic disorders in female smokers may be more serious than that in male smokers. CONCLUSIONS: Klotho-related molecules showed a differential association and response to smoking between men and women.

Molecular Characterization of Striated Muscle-Specific Gab1 Isoform as a Critical Signal Transducer for Neuregulin-1/ErbB Signaling in Cardiomyocytes.

Grb2-associated binder (Gab) docking proteins regulate signals downstream of a variety of growth factors and receptor tyrosine kinases. Neuregulin-1 (NRG-1), a member of epidermal growth factor family, plays a critical role for cardiomyocyte proliferation and prevention of heart failure via ErbB receptors. We previously reported that Gab1 and Gab2 in the myocardium are essential for maintenance of myocardial function in the postnatal heart via transmission of NRG-1/ErbB-signaling through analysis of Gab1/Gab2 cardiomyocyte-specific double knockout mice. In that study, we also found that there is an unknown high-molecular weight (high-MW) Gab1 isoform (120 kDa) expressed exclusively in the heart, in addition to the ubiquitously expressed low-MW (100 kDa) Gab1. However, the high-MW Gab1 has been molecularly ill-defined to date. Here, we identified the high-MW Gab1 as a striated muscle-specific isoform. The high-MW Gab1 has an extra exon encoding 27 amino acid residues between the already-known 3rd and 4th exons of the ubiquitously expressed low-MW Gab1. Expression analysis by RT-PCR and immunostaining with the antibody specific for the high-MW Gab1 demonstrate that the high-MW Gab1 isoform is exclusively expressed in striated muscle including heart and skeletal muscle. The ratio of high-MW Gab1/ total Gab1 mRNAs increased along with heart development. The high-MW Gab1 isoform in heart underwent tyrosine-phosphorylation exclusively after intravenous administration of NRG-1, among several growth factors. Adenovirus-mediated overexpression of the high-MW Gab1 induces more sustained activation of AKT after stimulation with NRG-1 in cardiomyocytes compared with that of ß-galactosidase. On the contrary, siRNA-mediated knockdown of the high-MW Gab1 significantly attenuated AKT activation after stimulation with NRG-1 in cardiomyocytes. Taken together, these findings suggest that the striated muscle-specific high-MW isoform of Gab1 has a crucial role for NRG-1/ErbB signaling in cardiomyocytes.

Klotho-related Molecules Upregulated by Smoking Habit in Apparently Healthy Men: A Cross-sectional Study.

While aging is unavoidable, the aging mechanism is still unclear because of its complexity. Smoking causes premature death and is considered as an environmental aging accelerator. In the present study, we focused on the influence of smoking to the serum concentration of anti-aging protein α-klotho (αKl) and the ß-klotho-associated protein fibroblast growth factor (FGF)-21 in men. Subjects consisted of apparently healthy men over 40 years of age who underwent health examination. Physical and biochemical parameters, including the levels of several cytokines and growth factors, were obtained from the subjects. Among middle-aged men (46.1 ± 5.1 years), serum levels of FGF-21, soluble αKl (sαKl), and inflammation-related cytokine interleukin (IL)-6 were significantly higher in smokers than in never-smokers. Serum levels of FGF-21 increased and correlated with alanine transaminase, γ guanosine-5'-triphosphate, and total cholesterol only in smokers, suggesting FGF-21 as a metabolic disorder-related factor in smokers. In aged men (60.3 ± 1.7 years), although the serum levels of sαKl in never-smokers were low, smokers showed highly increased serum levels of sαKl. Serum levels of sαKl was correlated with IL-6 in middle-aged never-smokers, suggesting sαKl regulates IL-6. However, this correlation was disrupted in smokers and aged men.

Interleukin-6/interleukin-21 signaling axis is critical in the pathogenesis of pulmonary arterial hypertension.

IL-6 is a multifunctional proinflammatory cytokine that is elevated in the serum of patients with pulmonary arterial hypertension (PAH) and can predict the survival of patients with idiopathic PAH (IPAH). Previous animal experiments and clinical human studies indicate that IL-6 is important in PAH; however, the molecular mechanisms of IL-6-mediated pathogenesis of PAH have been elusive. Here we identified IL-21 as a downstream target of IL-6 signaling in PAH. First, we found that IL-6 blockade by the monoclonal anti-IL-6 receptor antibody, MR16-1, ameliorated hypoxia-induced pulmonary hypertension (HPH) and prevented the hypoxia-induced accumulation of Th17 cells and M2 macrophages in the lungs. Consistently, the expression levels of IL-17 and IL-21 genes, one of the signature genes for Th17 cells, were significantly up-regulated after hypoxia exposure in the lungs of mice treated with control antibody but not in the lungs of mice treated with MR16-1. Although IL-17 blockade with an anti-IL-17A neutralizing antibody had no effect on HPH, IL-21 receptor-deficient mice were resistant to HPH and exhibited no significant accumulation of M2 macrophages in the lungs. In accordance with these findings, IL-21 promoted the polarization of primary alveolar macrophages toward the M2 phenotype. Of note, significantly enhanced expressions of IL-21 and M2 macrophage markers were detected in the lungs of IPAH patients who underwent lung transplantation. Collectively, these findings suggest that IL-21 promotes PAH in association with M2 macrophage polarization, downstream of IL-6-signaling. The IL-6/IL-21-signaling axis may be a potential target for treating PAH.

[Ischemic heart disease in women].

Although significant advances in our knowledge about interventions to prevent and treat ischemic heart disease (IHD) have occurred, there are many differences between women and men in the symptom and pathophysiology of IHD. As IHD is one of the most prominent disease areas that gender difference exist; chest pain is not typical, sometimes angiography shows normal coronary, and poor prognosis because of delayed diagnosis in association with many risk factors in women. Smoking is the # 1 risk factor for the onset of acute myocardial infarction in women, whereas hypertension is the #1 risk in men. Overwhelming evidence suggests that IHD can be prevented in both women and men, however, much attention should be paid for female natients with IHD.

Smoking associates with visceral fat accumulation especially in women.

BACKGROUND: Smoking and metabolic syndrome (MetS) are major public health problems in modern society and are important risk factors of cardiovascular disease (CVD). The association of smoking, MetS, and CVD is widely reported, but reports targeted to women are few. In the present study, we evaluated risk factors, including visceral fat area (VFA), for CVD and development of subclinical atherosclerosis in female smokers especially. METHODS AND RESULTS: Subjects consisted of 162 apparent healthy female and male smokers, and 315 age-matched never-smokers who underwent a health examination in the Osaka University Health Care Center. For female smokers, lifestyle and carotid intima-media thickness (IMT) were evaluated. Triglycerides were significantly higher and high-density lipoprotein-cholesterol significantly lower in smokers than in never-smokers for both men and women. However, VFA was significantly high only in smoking women when compared with never-smokers. Multivariate analysis revealed that age, body mass index, and smoking were the independent predictors of high VFA in women. In addition, annual IMT increase was significantly higher in smokers than never-smokers in women. CONCLUSIONS: VFA was notably high in female smokers, but the difference was not observed in men. Smoking habit is an important risk factor of visceral fat accumulation and progression of subclinical atherosclerosis in women.

Disease-association analysis of an inflammation-related feedback loop.

The IL-6-triggered positive feedback loop for NFκB signaling (or the IL-6 amplifier/Inflammation amplifier) was originally discovered as a synergistic-activation signal that follows IL-17/IL-6 stimulation in nonimmune cells. Subsequent results from animal models have shown that the amplifier is activated by stimulation of NFκB and STAT3 and induces chemokines and inflammation via an NFκB loop. However, its role in human diseases is unclear. Here, we combined two genome-wide mouse screens with SNP-based disease association studies, revealing 1,700 genes related to the IL-6 amplifier, 202 of which showed 492 indications of association with ailments beyond autoimmune diseases. We followed up on ErbB1 from our list. Blocking ErbB1 signaling suppressed the IL-6 amplifier, whereas the expression of epiregulin, an ErbB1 ligand, was higher in patients with inflammatory diseases. These results indicate that the IL-6 amplifier is indeed associated with human diseases and disorders and that the identified genes may make for potential therapeutic targets.

Smoking promotes subclinical atherosclerosis in apparently healthy men: 2-year ultrasonographic follow-up.

BACKGROUND: Smoking is a major risk factor for cardiovascular disease. Also, inflammatory activation and metabolic disorder are the mediators of smoking-induced atherosclerotic progression. The aim of the present study was to investigate whether current smoking and smoking cessation alter inflammatory or metabolic status and affect subclinical atherosclerosis in apparently healthy men. METHODS AND RESULTS: Classical risk factors and smoking habit were evaluated in 354 men who completed health examinations annually without any current medications. Carotid intima-media thickness (IMT) was followed for 27.1±4.5 months. At baseline, both maximum and mean IMT significantly changed during 2-year follow-up. They tended to increase along with progression of smoking habit, with significantly greater maximum IMT in current smokers compared with never smokers. Both maximum and mean IMT significantly changed during 2-year follow-up, and tended to increase with progression of smoking habit, with maximum IMT being greatest for current smokers. Past smokers tended to have greater IMT increase than never smokers. Among smoking habit and some atherosclerotic risk markers that showed significant correlation with maximum IMT increase, stepwise regression showed that smoking habit and serum low-density lipoprotein-cholesterol (LDL-C) level were the only independent predictors. CONCLUSIONS: Significant 2-year progression of subclinical atherosclerosis was associated with continuous smoking and LDL-C. This was only partly moderated in past smokers despite complete reversal of inflammatory activation, suggesting another crucial factor for inhibiting accelerated progression of subclinical atherosclerosis in men.

Endothelial Gab1 deletion accelerates angiotensin II-dependent vascular inflammation and atherosclerosis in apolipoprotein E knockout mice.

BACKGROUND: Docking protein Grb2-associated binder 1 (Gab1) has critical roles in signal transduction of various growth factors, cytokines, and numerous other molecules. Our previous reports show that Gab1 is essential for postnatal angiogenesis through the analysis of endothelium-specific Gab1 knockout (Gab1ECKO) mice. However, the role of Gab1 in atherosclerosis remains unknown. The aim of the present study was to elucidate the role of endothelial Gab1 in vascular inflammation and atherosclerosis. METHODS AND RESULTS: We intercrossed Gab1ECKO mice with apolipoprotein E (ApoE) knockout (ApoEKO) mice. Six-month-old male ApoEKO/Gab1ECKO and littermate control (ApoEKO) mice were treated with angiotensin II (AngII) via an osmotic infusion mini-pump. After AngII treatment, ApoEKO/Gab1ECKO mice showed significantly enhanced atherosclerosis and aneurysm formation compared with control mice. The production of proinflammatory cytokines in the aorta was significantly enhanced in ApoEKO/Gab1ECKO mice compared with control mice. Furthermore, the expression levels of Krüppel-like factor (KLF) 2 (KLF2) and KLF4, key transcription factors for endothelial homeostasis, were significantly reduced in the aortic endothelium of ApoEKO/Gab1ECKO mice compared with those of control mice. Consistently, both vascular cell adhesion molecule-1 expression and macrophage infiltration on the aortic walls were enhanced in ApoEKO/Gab1ECKO mice compared with control mice. CONCLUSIONS: Collectively, endothelial Gab1 deletion accelerates AngII-dependent vascular inflammation and atherosclerosis on ApoE-null background presumably in association with downregulation of KLF2 and KLF4.

Self-reported sleep duration and prediction of proteinuria: a retrospective cohort study.

BACKGROUND: Although multiple studies have shown that sleep duration is a predictor of cardiovascular diseases and mortality, few studies have reported an association between sleep duration and chronic kidney disease. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 6,834 employees of Osaka University aged 20-65 years who visited Osaka University Healthcare Center for their mandatory annual health examinations between April 2006 and March 2010 and did not have estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2), proteinuria, or treatment for self-reported kidney disease. PREDICTOR: Self-reported questionnaires about life style, including sleep duration, and blood and urine testing at the first examinations during the study period. An association between sleep duration and outcome was assessed using multivariate Poisson regression models adjusting for clinically relevant factors. OUTCOME: Time to the development of proteinuria defined as 1+ or higher by dipstick test. RESULTS: Self-reported baseline sleep duration was 6.0 ± 0.9 hours, which reflected the mean sleep duration during a median of 2.5 (25th-75th percentile, 1.4-3.9) years of the observational period. Development of proteinuria was observed in 550 employees (8.0%). A multivariate Poisson regression model clarified that shorter sleep duration, especially 5 or fewer hours, was associated with the development of proteinuria in a stepwise fashion (vs 7 hours; incidence rate ratios of 1.07 [95% CI, 0.87-1.33; P = 0.5], 1.28 [95% CI, 1.00-1.62; P = 0.05], and 1.72 [95% CI, 1.16-2.53; P = 0.007] for 6, 5, and ≤4 hours, respectively), along with younger age, heavier current smoking, trace urinary protein by dipstick test, higher eGFR, higher serum hemoglobin A(1c) level, and current treatment for heart disease. A stepwise association between shorter sleep duration and the development of proteinuria also was verified in 4,061 employees who did not work the night shift. LIMITATIONS: Self-reported sleep duration might be biased. Results in a single center should be confirmed in the larger cohort including different occupations. CONCLUSION: Short sleep duration, especially 5 or fewer hours, was a predictor of proteinuria.

Docking protein Gab1 is an essential component of postnatal angiogenesis after ischemia via HGF/c-met signaling.

RATIONALE: Grb2-associated binder (Gab) docking proteins, consisting of Gab1, Gab2, and Gab3, have crucial roles in growth factor-dependent signaling. Various proangiogenic growth factors regulate angiogenesis and endothelial function. However, the roles of Gab proteins in angiogenesis remain elusive. OBJECTIVE: To elucidate the role of Gab proteins in postnatal angiogenesis. METHODS AND RESULTS: Endothelium-specific Gab1 knockout (Gab1ECKO) mice were viable and showed no obvious defects in vascular development. Therefore, we analyzed a hindlimb ischemia (HLI) model of control, Gab1ECKO, or conventional Gab2 knockout (Gab2KO) mice. Intriguingly, impaired blood flow recovery and necrosis in the operated limb was observed in all of Gab1ECKO, but not in control or Gab2KO mice. Among several proangiogenic growth factors, hepatocyte growth factor (HGF) induced the most prominent tyrosine phosphorylation of Gab1 and subsequent complex formation of Gab1 with SHP2 (Src homology-2-containing protein tyrosine phosphatase 2) and phosphatidylinositol 3-kinase subunit p85 in human endothelial cells (ECs). Gab1-SHP2 complex was required for HGF-induced migration and proliferation of ECs via extracellular signal-regulated kinase (ERK)1/2 pathway and for HGF-induced stabilization of ECs via ERK5. In contrast, Gab1-p85 complex regulated activation of AKT and contributed partially to migration of ECs after HGF stimulation. Microarray analysis demonstrated that HGF upregulated angiogenesis-related genes such as KLF2 (Krüppel-like factor 2) and Egr1 (early growth response 1) via Gab1-SHP2 complex in human ECs. In Gab1ECKO mice, gene transfer of vascular endothelial growth factor, but not HGF, improved blood flow recovery and ameliorated limb necrosis after HLI. CONCLUSION: Gab1 is essential for postnatal angiogenesis after ischemia via HGF/c-Met signaling.

The efficacy of tocilizumab in a patient with pulmonary arterial hypertension associated with Castleman's disease.

Castleman's disease is a highly heterogeneous clinical-pathological entity that belongs to the lymphoproliferative disorders and is associated with pulmonary arterial hypertension (PAH) in some patients. It is linked to excessive immune stimulation by interleukin-6 (IL-6), which is also involved in the pathogenesis of PAH. A 31-year-old woman with Castleman's disease demonstrated PAH characterized by severe right heart failure. Since she was resistant to various conventional therapies including steroids, prostacyclins, bosentan, and sildenafil, tocilizumab (anti-IL-6 receptor antibody) therapy was started. Her clinical course was followed for 6 months, with significant improvement without any adverse effect. This is the first reported case of use of tocilizumab in addition to steroids and conventional PAH therapy in a patient with PAH associated with Castleman's disease.