Novel pathophysiological roles of α-synuclein in age-related vascular endothelial dysfunction.

Although α-synuclein (SNCA) is a well-known pathological molecule involved in synucleinopathy in neurons, its physiological roles remain largely unknown. We reported that serum SNCA levels have a close inverse correlation with blood pressure and age, which indicates the involvement of SNCA in age-related endothelial dysfunction. Therefore, this study aimed to elucidate the molecular functions of SNCA in the endothelium. We confirmed that SNCA was expressed in and secreted from endothelial cells (ECs). Exogenous treatment with recombinant SNCA (rSNCA) activated the Akt-eNOS axis and increased nitric oxide production in ECs. Treatment with rSNCA also suppressed TNF-α- and palmitic acid-induced NF-κB activation, leading to the suppression of VCAM-1 upregulation and restoration of eNOS downregulation in ECs. As for endogenous SNCA expression, replicative senescence resulted in the attenuation of SNCA expression in cultured ECs, similar to the effects of physiological aging on mice aortas. The siRNA-mediated silencing of SNCA consistently resulted in senescent phenotypes, such as eNOS downregulation, increased ß-gal activity, decreased Sirt1 expression, and increased p53 expression, in ECs. Ex vivo assessment of endothelial functions using aortic rings revealed impaired endothelium-dependent acetylcholine-induced relaxation in SNCA knockout (KO) mice. Furthermore, SNCA KO mice, especially those on a high-fat diet, displayed elevated blood pressure compared with wild-type mice; this could be eNOS dysfunction-dependent because of the lower difference caused by L-NAME administration. These results indicate that exogenous and endogenous SNCA in ECs might physiologically maintain vascular integrity, and age-related endothelial dysfunction might be partially ascribed to loss-of-function of SNCA in ECs.

Antiepileptic Drugs Modulate Alzheimer-Related Tau Aggregation in a Neuronal Activity-Independent Manner.

INTRODUCTION: A rapidly increasing number of patients with dementia present a serious social problem. Recently, the incidence of epilepsy in patients with Alzheimer's disease (AD) is increasing, drawing attention to the pathological relationship between the two conditions. Clinical studies have suggested the protective action of antiepileptic agents on dementia; however, the underlying mechanism remains unknown. We evaluated the effects of multiple antiepileptic drugs using tau aggregation assay systems to determine the effects of antiepileptic agents on tau aggregation, a major neuropathological finding associated with AD. METHODS: We evaluated the effects of seven antiepileptic agents on intracellular tau aggregation using a tau-biosensor cell-based high-throughput assay. Next, we tested these agents in a cell-free tau aggregation assay using thioflavin T (ThT). RESULTS: The assay results revealed that phenobarbital inhibited tau aggregation, whereas sodium valproate, gabapentin, and piracetam promoted tau aggregation. In the cell-free tau aggregation assay using ThT, we confirmed that phenobarbital significantly inhibited tau aggregation. CONCLUSION: Antiepileptic drugs may modify the tau pathology in AD in a neural activity-independent manner. Our finding may provide an important insight into the optimization of antiepileptic drug therapy in older adults with dementia.

Effects of luseogliflozin treatment on hyperglycemia-induced muscle atrophy in rats.

Diabetes mellitus is recognized as a risk factor for sarcopenia. Luseogliflozin, a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, reduces inflammation and oxidative stress by improving hyperglycemia, subsequently improving hepatosteatosis or kidney dysfunction. However, the effects of SGLT2 inhibitor on the regulation of skeletal muscle mass or function in hyperglycemia are still unknown. In this study, we investigated the effects of luseogliflozin-mediated attenuation of hyperglycemia on the prevention of muscle atrophy. Twenty-four male Sprague-Dawley rats were randomly divided into four groups: control, control with SGLT2 inhibitor treatment, hyperglycemia, and hyperglycemia with SGLT2 inhibitor treatment. The hyperglycemic rodent model was established using a single injection of streptozotocin, a compound with preferential toxicity toward pancreatic beta cells. Muscle atrophy in streptozotocin-induced hyperglycemic model rats was inhibited by the suppression of hyperglycemia using luseogliflozin, which consequently suppressed hyperglycemia-mediated increase in the levels of advanced glycation end products (AGEs) and activated the protein degradation pathway in muscle cells. Treatment with luseogliflozin can restore the hyperglycemia-induced loss in the muscle mass to some degree partly through the inhibition of AGEs-induced or homeostatic disruption of mitochondria-induced activation of muscle degradation.

A pressor dose of angiotensin II has no influence on the angiotensin-converting enzyme 2 and other molecules associated with SARS-CoV-2 infection in mice.

In the early phase of the Coronavirus disease 2019 (COVID-19) pandemic, it was postulated that the renin-angiotensin-system inhibitors (RASi) increase the infection risk. This was primarily based on numerous reports, which stated that the RASi could increase the organ Angiotensin-converting enzyme 2 (ACE2), the receptor of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in rodents. RASi can theoretically antagonize the potential influence of angiotensin II (Ang II) on ACE2. However, while Ang II decreases the ACE2 levels in cultured cells, there is little evidence that supports this phenomenon in living animals. In this study, we tested whether Ang II or Ang II combined with its antagonist would alter the ACE2 and other molecules associated with the infection of SARS-CoV-2. Male C57BL6/J mice were administered vehicle, Ang II (400 ng/kg/min), or Ang II with losartan (10 mg/kg/min) for 2 weeks. ACE2 knockout mice were used as a negative control for the ACE2 assay. We found that both Ang II, which elevated blood pressure by 30 mm Hg, and Ang II with losartan, had no effect on the expression or protein activity of ACE2 in the lung, left ventricle, kidney, and ileum. Likewise, these interventions had no effect on the expression of Transmembrane Protease Serine 2 (TMPRSS2) and Furin, proteases that facilitate the virus-cell fusion, and the expression or activity of Tumor Necrosis Factor α-Convertase (TACE) that cleaves cell-surface ACE2. Collectively, physiological concentrations of Ang II do not modulate the molecules associated with SARS-CoV-2 infection. These results support the recent observational studies suggesting that the use of RASi is not a risk factor for COVID-19.

Interleukin-15 receptor subunit alpha regulates interleukin-15 localization and protein expression in skeletal muscle cells.

NEW FINDINGS: What is the central question of this study? How are the dynamics of interleukin (IL)-15 and its receptors altered during the differentiation of myoblasts into myotubes, and how is IL-15 regulated? What is the main finding and its importance? The mRNA levels of IL-15 and interleukin-2 receptor subunits beta and gamma increase during skeletal muscle differentiation, whereas interleukin-15 receptor subunit alpha (IL-15RA) exhibits different kinetics. IL-15RA regulates the localization and expression of IL-15 at the protein level. ABSTRACT: Interleukin-15 (IL-15) is a myokine in the interleukin-2 (IL-2) family that is generated in the skeletal muscle during exercise. The functional effect of IL-15 involves muscle regeneration and metabolic regulation in skeletal muscle. Reports have indicated that interleukin-15 receptor subunit alpha (IL-15RA) acts by regulating IL-15 localization in immune cells. However, the dynamics of IL-15 and its receptors, which regulate the IL-15 pathway in skeletal muscle differentiation, have not yet been clarified. In this study, we investigated the mechanism of IL-15 regulation using a mouse skeletal muscle cell line, C2C12 cells. We found that the mRNA expression of IL-15, interleukin-2 receptor subunit beta (IL-2RB; CD122) and interleukin-2 receptor subunit gamma (IL-2RG; CD132) increased, but that IL-15RA exhibited different kinetics as differentiation progressed. We also found that IL-15, mainly present in the cytosol, pre-assembled with IL-15RA in the cytosol and fused to the plasma membrane. Moreover, IL-15RA increased IL-15 protein levels. Our findings suggest that genes involved in the IL-15 signalling complex are enhanced with the differentiation of myotubes and that IL-15RA regulates the protein kinetics of IL-15 signalling in skeletal muscle.

Alcohol drinking patterns have a positive association with cognitive function among older people: a cross-sectional study.

BACKGROUND: The relationship between moderate alcohol drinking or other alcohol drinking patterns such as frequency, beverage type, and situation of drinking and cognitive function is not sufficiently clear in older people. The purpose of this study was to investigate the association between alcohol drinking patterns and cognitive function in community-dwelling Japanese people aged 75 and over. METHODS: This study was a cross-sectional design based on a prospective cohort study called the SONIC study. Subjects were older people aged 75-77 or 85-87 who voluntarily participated in 2016-2017. Drinking information was collected for daily drinking frequency, daily drinking intake, beverage type, and non-daily drinking opportunity. Cognitive function was measured using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Other potential confounding factors evaluated were age, sex, medical factors, and psychosocial factors. An analysis of covariance was performed to evaluate the MoCA-J score relative to drinking frequency or alcohol intake. Multiple regression analysis was performed to investigate the association between beverage type or non-daily drinking opportunity and the MoCA-J score. RESULTS: The final number of participants analyzed was 1,226. The MoCA-J score for participants who reported drinking alcohol 1-6 days/week was significantly higher than that for those who reported drinking none or every day. No significant difference in the MoCA-J score was observed relative to daily alcohol intake. In terms of beverage type, wine was associated positively with the MoCA-J score. Non-daily drinking opportunity was also associated positively with the MoCA-J score. CONCLUSIONS: Moderate-frequency drinking, wine consumption, and non-daily drinking opportunities were associated with higher cognitive function in community-dwelling Japanese aged 75 and over. Further longitudinal studies are needed to clarify the causal relationships.

Novel properties of myoferlin in glucose metabolism via pathways involving modulation of adipose functions.

While adipose tissue is required to maintain glucose metabolism, excessive calorie intake induces obesity via mechanisms including accelerated proliferation and differentiation of preadipocytes, leading to insulin resistance. Here, we investigated the role of myoferlin (MYOF), a ferlin family protein, in regulating glucose metabolism by mainly focusing on its unknown role in adipose tissue. Whereas young MYOF knockout (KO) mice on a normal diet showed aggravated glucose tolerance and insulin sensitivity, those on a high-fat diet (HFD) showed preserved glucose tolerance with an attenuated gain of body weight, reduced visceral fat deposits, and less severe fatty liver. The Adipose MYOF expression was reduced by aging but was restored by an HFD along with the retained expression of NFAT transcription factors. Loss-of-function of MYOF in preadipocytes suppressed proliferation and differentiation into mature adipocytes along with the decreased expression of genes involved in adipogenesis. The MYOF expression in preadipocytes was reduced with differentiation. Attenuated obesity in MYOF KO mice on an HFD was also accompanied with increased oxygen consumption by an unidentified mechanism and with reduced adipose inflammation due to less inflammatory macrophages. These insights suggest that the multifunctional roles of MYOF involve the regulation of preadipocyte function and affect glucose metabolism bidirectionally depending on consumed calories.

The myeloid transcription factor KLF2 regulates the host response to polymicrobial infection and endotoxic shock.

Precise control of myeloid cell activation is required for optimal host defense. However, this activation process must be under exquisite control to prevent uncontrolled inflammation. Herein, we identify the Kruppel-like transcription factor 2 (KLF2) as a potent regulator of myeloid cell activation in vivo. Exposure of myeloid cells to hypoxia and/or bacterial products reduced KLF2 expression while inducing hypoxia inducible factor-1α (HIF-1α), findings that were recapitulated in human septic patients. Myeloid KLF2 was found to be a potent inhibitor of nuclear factor-kappaB (NF-κB)-dependent HIF-1α transcription and, consequently, a critical determinant of outcome in models of polymicrobial infection and endotoxemia. Collectively, these observations identify KLF2 as a tonic repressor of myeloid cell activation in vivo and an essential regulator of the innate immune system.

The importance of stroke as a risk factor of cognitive decline in community dwelling older and oldest peoples: the SONIC study.

BACKGROUND: Cognitive impairment is a major health concern among older and oldest people. Moreover, stroke is a relevant contributor for cognitive decline and development of dementia. The study of cognitive decline focused on stroke as the important risk factor by recruiting older and oldest is still lagging behind. Therefore, the aim of this study was to investigate the importance of stroke as a risk factor of cognitive decline during 3 years in community dwelling older and oldest people. METHODS: This study was longitudinal study with a 3-year follow-up in Japan. The participants were 1333 community dwelling older and oldest people (70 years old = 675, 80 years old = 589, and 90 years old = 69). Data collected included basic data (age, sex, and history of stroke), vascular risk factors (hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation, and current smoking), and social factors (educational level, frequency of going outdoors, long-term care (LTC) service used, and residential area). The Japanese version of the Montreal Cognitive Assessment (MoCA-J) was decline of ≥2 points was defined as cognitive decline. Multiple logistic regression analysis was used to investigate the association between stroke and other risk factors with cognitive decline during a 3-year follow-up. RESULTS: The fit of the hypothesized model by multiple logistic regression showed that a history of stroke, advanced age, and greater MoCA-J score at the baseline were important risk factors, while the presence of dyslipidemia and a higher educational level were protective factors that were significantly correlated with cognitive decline during the 3-year follow-up. CONCLUSIONS: The cognitive decline after the 3-year follow-up was influenced by the history of stroke and advanced age, while greater MoCA-J score at the baseline was positively associated with subsequent 3 years cognitive decline. The protective factors were the presence of dyslipidemia and a higher educational level. Therefore, these factors are considered important and should be taken into consideration when searching for creative solutions to prevent cognitive decline after stroke in community dwelling older and oldest people.

Association between physical function and long-term care in community-dwelling older and oldest people: the SONIC study.

BACKGROUND: Preventing the need for long-term care (LTC) by identifying physical function risk factors are important to decrease the LTC burden. The objective of this study was to investigate whether grip strength and/or walking speed, which are components of the frailty definition, are associated with LTC in community-dwelling older and oldest people. METHODS: The participants were 1098 community-dwelling older and oldest people who had not received LTC at the baseline. The endpoint was receiving LTC after the baseline survey. The independent variables were grip strength and walking speed, and participants were divided into two groups based on these variables. The confounding factors were age, sex, the Japanese version of the Montreal Cognitive Assessment (MoCA-J), hypertension, diabetes mellitus, stroke, joint diseases, living alone, body mass index, and serum albumin. We calculated the hazard ratio of receiving LTC using the Cox proportional hazard model. RESULTS: Among the 1098 participants, 107 (9.7%) newly received LTC during the follow-up. Regarding the physical function, only slow walking speed was significantly correlated with LTC after adjusting for all confounding factors except the MoCA-J score (HR = 1.74, 95% CI = 1.10-2.75, P = .018). However, slow walking speed was still a risk factor for LTC after adjusting for the MoCA-J score and other confounding factors (HR = 1.64, 95% CI = 1.03-2.60, P = .037). CONCLUSIONS: The findings from this study may contribute to a better understanding of slow walking speed as a factor related to LTC, which might be a criterion for disability prevention and could serve as an outcome measure for physical function in older people.

Overexpression of Interleukin-15 exhibits improved glucose tolerance and promotes GLUT4 translocation via AMP-Activated protein kinase pathway in skeletal muscle.

Skeletal muscle performs 80% of the glucose metabolism in the body. Improvement of insulin resistance and prevention of diabetes by habitual exercise is considered beneficial due to the improved glucose uptake in skeletal muscles. Investigation of the mechanism by which skeletal muscles regulate glucose uptake can contribute to the prevention and treatment of diabetes. Myokines are a kind of cytokine secreted from skeletal muscle, which are expected to regulate muscle metabolism. Interleukin-15 (IL-15) is one such myokine that has been reported to improve glucose metabolism in vitro, although the mechanism remains unclear. In this study, we examined the glucose metabolism of skeletal muscle-specific IL-15 transgenic mice (IL-15TG), and investigated how IL-15 affects glucose metabolism in skeletal muscles. Although High Fat Diet-fed IL-15TG did not exhibit obvious difference in intraperitoneal insulin tolerance test, they had less impaired glucose tolerance compared to wild-type C57BL/6. Phosphorylation of AMP-activated protein kinase (AMPK), Akt substrate of 160 kDa (AS160), tre-2/USP6, BUB2, and cdc16 domain family member 1 (TBC1D1), and translocation of Glucose transporter type 4 (GLUT4) were accelerated in the skeletal muscle of IL-15TG. Our study demonstrated that overexpression of IL-15 in skeletal muscle improves glucose metabolism in skeletal muscle via AMPK pathway. We report the first in-vivo study that describes the signaling pathway of IL-15 in muscle glucose metabolism, and thereby contributes to the elucidation of the regulatory mechanism of muscle glucose metabolism by myokines.

Pathophysiological significance of cylindromatosis in the vascular endothelium and macrophages for the initiation of age-related atherogenesis.

Cardiovascular disease is one of the leading causes of death in the elderly, and novel therapeutic targets against atherogenesis are urgent. The initiation of atherosclerotic changes of monocyte adhesion on the vascular endothelium and subsequent foam cell formation are noteworthy pathophysiologies when searching for strategies to prevent the progression of age-related atherosclerosis. We report the significance of the deubiquitinating enzyme cylindromatosis (CYLD) in vascular remodeling by interference with inflammatory responses regulated by NF-κB signaling. The purpose of this study was to elucidate the pathological functions of CYLD in the early phase of atherogenesis associated with aging. Treatment with inflammatory cytokines induced endogenous CYLD in aortic endothelial cells (HAECs) and THP-1 cells. siRNA-mediated CYLD silencing led to enhanced monocyte adhesion along with increased adhesion molecules in HAECs treated with TNFα. In siRNA-mediated CYLD silenced RAW 264.7 macrophages treated with oxidized LDL (oxLDL), augmented lipid accumulation was observed, along with increased expression of the class A macrophage scavenger receptor (SR-A), lectin-like oxidized LDL receptor-1 (LOX-1), CD36, fatty acid binding protein 4 (FABP4), the cholesterol ester synthase acyl-CoA cholesterol acyltransferase (ACAT1), MCP-1, and IL-1ß and decreased expression of scavenger receptor class B type I (SR-BI). Intriguingly, CYLD gene expression was significantly reduced in bone marrow-derived macrophages of aged mice compared that of young mice, as well as in senescent HAECs compared with young cells. These findings suggest that age-related attenuation of CYLD expression in endothelial cells (ECs) and macrophages triggers the initiation of age-related atherogenesis by exacerbating monocyte adhesion on the endothelium and foam cell formation. CYLD in the vasculature may be a novel therapeutic target, especially in the early preventive intervention against the initiation of age-related atherogenesis.

Angiotensin 1-7 alleviates aging-associated muscle weakness and bone loss, but is not associated with accelerated aging in ACE2-knockout mice.

The angiotensin-converting enzyme 2 (ACE2)-angiotensin 1-7 (A1-7)-A1-7 receptor (Mas) axis plays a protective role in the renin-angiotensin system (RAS). We recently found that ACE2 knockout (ACE2KO) mice exhibit earlier aging-associated muscle weakness, and that A1-7 alleviates muscle weakness in aging mice. In the present study, we investigated the role of the A1-7-Mas pathway in the effect of ACE2 on physiological aging. Male wild-type, ACE2KO, and Mas knockout (MasKO) mice were subjected to periodical grip strength measurement, followed by administration of A1-7 or vehicle for 4 weeks at 24 months of age. ACE2KO mice exhibited decreased grip strength after 6 months of age, while grip strength of MasKO mice was similar to that of wild-type mice. A1-7 improved grip strength in ACE2KO and wild-type mice, but not in MasKO mice. Muscle fibre size was smaller in ACE2KO mice than that in wild-type and MasKO mice, and increased with A1-7 in ACE2KO and WT mice, but not in MasKO mice. Centrally nucleated fibres (CNFs) and expression of the senescence-associated gene p16INK4a in skeletal muscles were enhanced only in ACE2KO mice and were not altered by A1-7. ACE2KO mice, but not MasKO mice, exhibited thinning of peripheral fat along with increased adipose expression of p16INK4a A1-7 significantly increased bone volume in wild-type and ACE2KO mice, but not in MasKO mice. Our findings suggest that the impact of ACE2 on physiological aging does not depend on the endogenous production of A1-7 by ACE2, while overactivation of the A1-7-Mas pathway could alleviate sarcopenia and osteoporosis in aged mice.

Effects of Low-Dose Sacubitril/Valsartan on Different Stages of Cardiac Hypertrophy in Salt-Loaded Hypertensive Rats.

BACKGROUND: Sacubitril/valsartan was shown to attenuate the development of cardiac hypertrophy with enhanced blood pressure reduction compared with valsartan alone in animal models. We investigated whether a low-dose sacubitril/valsartan has blood pressure-independent effects on cardiac hypertrophy and pulmonary edema using a rat model of hypertension and obesity. METHODS AND RESULTS: In plan 1, male SHR/NDmcr-cp rats fed normal or phase-increased high salt were treated with vehicle, 6-mg/kg sacubitril/valsartan or 3-mg/kg valsartan, for 6 months. In plan 2, after high-salt loading for 6 months, drugs were administered for 4 months. Antihypertensive effects of the 2 drugs were similar during all study periods. In plan 1 with normal salt, there were no differences between treatments in the left ventricle weight/body weight (BW), or lung weight/BW as an index of cardiac hypertrophy or pulmonary edema, respectively. These indexes were smaller in high-salt-fed rats with sacubitril/valsartan than vehicle. In plan 2, both indexes did not differ between vehicle and sacubitril/valsartan. Ventricle weight/BW was lower in valsartan than sacubitril/valsartan. In plan 2, gene markers of cardiac dysfunction were upregulated by sacubitril/valsartan compared with the other groups. CONCLUSIONS: Low-dose sacubitril/valsartan may have different effects depending on the stage of cardiac hypertrophy in rats.

Glial fibrillary acidic protein (GFAP) is a novel biomarker for the prediction of autoimmune diabetes.

Glial fibrillary acidic protein (GFAP) is expressed in peri-islet Schwann cells, as well as in glia cells, and has been reported to be an autoantigen candidate for type 1 diabetes mellitus (T1DM). We confirmed that the production of the autoantibodies GFAP and glutamic acid decarboxylase 65 (GAD65) was increased and inversely correlated with the concentration of secreted C peptide in female nonobese diabetic mice (T1DM model). Importantly, the development of T1DM in female nonobese diabetic mice at 30 wk of age was predicted by the positive GFAP autoantibody titer at 17 wk. The production of GFAP and GAD65 autoantibodies was also increased in KK-Ay mice [type 2 diabetes mellitus (T2DM) model]. In patients with diabetes mellitus, GFAP autoantibody levels were increased in patients with either T1DM or T2DM, and were significantly associated with GAD65 autoantibodies but not zinc transporter 8 autoantibodies. Furthermore, we identified a B-cell epitope of GFAP corresponding to the GFAP autoantibody in both mice and patients with diabetes. Thus, these results indicate that autoantibodies against GFAP could serve as a predictive marker for the development of overt autoimmune diabetes.-Pang, Z., Kushiyama, A., Sun, J., Kikuchi, T., Yamazaki, H., Iwamoto, Y., Koriyama, H., Yoshida, S., Shimamura, M., Higuchi, M., Kawano, T., Takami, Y., Rakugi, H., Morishita, R., Nakagumi, H. Glial fibrillary acidic protein (GFAP) is a novel biomarker for the prediction of autoimmune diabetes.

Therapeutic vaccine against DPP4 improves glucose metabolism in mice.

The increasing prevalence of type 2 diabetes mellitus is associated with a significant economic burden. We developed a dipeptidyl peptidase 4 (DPP4)-targeted immune therapy to increase glucagon-like peptide 1 hormone levels and improve insulin sensitivity for the prevention and treatment of type 2 diabetes mellitus. Immunization with the DPP4 vaccine in C57BL/6J mice successfully increased DPP4 titer, inhibited plasma DPP4 activity, and induced an increase in the plasma glucagon-like peptide 1 level. Moreover, this elevated titer was sustained for 3 mo. In mice fed a high-fat diet, DPP4 vaccination resulted in improved postprandial glucose excursions and insulin sensitivity and, in the diabetic KK-A(y) and db/db mice strains, DPP4 vaccination significantly reduced glucose excursions and increased both plasma insulin and pancreatic insulin content. Importantly, T cells were not activated following challenge with DPP4 itself, which suggests that this vaccine does not induce cell-mediated autoimmunity. Additionally, no significant immune-mediated damage was detected in cells and tissues where DPP4 is expressed. Thus, this DPP4 vaccine may provide a therapeutic alternative for patients with diabetes.

Oxidized LDL (oxLDL) activates the angiotensin II type 1 receptor by binding to the lectin-like oxLDL receptor.

The angiotensin II type 1 receptor (AT1) is a 7-transmembrane domain GPCR that when activated by its ligand angiotensin II, generates signaling events promoting vascular dysfunction and the development of cardiovascular disease. Here, we show that the single-transmembrane oxidized LDL (oxLDL) receptor (LOX-1) resides in proximity to AT1 on cell-surface membranes and that binding of oxLDL to LOX-1 can allosterically activate AT1-dependent signaling events. oxLDL-induced signaling events in human vascular endothelial cells were abolished by knockdown of AT1 and inhibited by AT1 blockade (ARB). oxLDL increased cytosolic G protein by 350% in Chinese hamster ovary (CHO) cells with genetically induced expression of AT1 and LOX-1, whereas little increase was observed in CHO cells expressing only LOX-1. Immunoprecipitation and in situ proximity ligation assay (PLA) assays in CHO cells revealed the presence of cell-surface complexes involving LOX-1 and AT1. Chimeric analysis showed that oxLDL-induced AT1 signaling events are mediated via interactions between the intracellular domain of LOX-1 and AT1 that activate AT1. oxLDL-induced impairment of endothelium-dependent vascular relaxation of vascular ring from mouse thoracic aorta was abolished by ARB or genetic deletion of AT1. These findings reveal a novel pathway for AT1 activation and suggest a new mechanism whereby oxLDL may be promoting risk for cardiovascular disease.

Prognostic impact of regional arterial stiffness in hypertensive patients.

Many reports have shown that brachial-ankle pulse wave velocity (baPWV) and carotid-femoral PWV are prognostic factors for cardiovascular diseases. We evaluated heart-carotid PWV, heart-femoral PWV (hfPWV), and femoral-ankle PWV (faPWV) using carotid and femoral sensors. Our objectives were to reveal correlations among PWVs and to determine the clinical importance of the respective PWVs in predicting the cardiovascular events. This prospective cohort study included 338 patients with essential hypertension (mean age 61.3 ± 0.7, mean follow-up period 6.5 ± 0.1 years) whose regional PWVs were measured. Primary end points were stroke, cardiovascular diseases (CVD), and death. Kaplan-Meier analysis showed that subjects with higher faPWV and baPWV had a significantly higher incidence of stroke (p = 0.0288 and 0.0277, respectively), subjects with higher hfPWV had a significantly higher incidence of CVD (p = 0.0212), subjects with higher baPWV and hfPWV had a significantly higher incidence of stroke + CVD (p = 0.0070 and 0.0463, respectively), and subjects with higher baPWV had a significantly higher mortality rate (p = 0.0367). Cox proportional hazard model revealed that baPWV was a significant risk factor for stroke + CVD after adjustment for traditional risk factors (relative risk: 14.50, p = 0.0288). Higher baPWV may be a risk factor for stroke and CVD, but the prognostic impact of regional PWVs is still unclear in patients with hypertension.

[Treatment of hypertension in the elderly].

Hypertension guideline has been revised as JSH2014. Because the elderly show marked individual differences in the physiological function, the therapeutic strategies should be individually selected, considering their QOL. As to general guidelines, drug therapy should be indicated for patients with a blood pressure of ≤ 140/90mmHg on principle. However, treatment indication must be individually assessed in persons, aged over 75 years, with a systolic blood pressure of 140-149 mmHg or frail elderly. Target blood pressure in persons aged 65-74 years should be < 140/90mmHg and that in those aged over 75 years should be < 150/90 mmHg. If treatment is well tolerated, more aggressive blood pressure control < 140/90mmHg may further improve the outcome. In patients with coronary artery disease, the risk of cardiac events may increase if diastolic blood pressure is < 70mmHg. Therefore, blood pressure control should be performed while monitoring the ischemic findings.

Kruppel-like factor 2 is a transcriptional regulator of chronic and acute inflammation.

Although myeloid cell activation is requisite for an optimal innate immune response, this process must be tightly controlled to prevent collateral host tissue damage. Kruppel-like factor 2 (KLF2) is a potent regulator of myeloid cell proinflammatory activation. As an approximately 30% to 50% reduction in KLF2 levels has been observed in human subjects with acute or chronic inflammatory disorders, we studied the biological response to inflammation in KLF2(+/-) mice. Herein, we show that partial deficiency of KLF2 modulates the in vivo response to acute (sepsis) and subacute (skin) inflammatory challenge. Mechanistically, we link the anti-inflammatory effects of KLF2 to the inhibition of NF-κB transcriptional activity. Collectively, the observations provide biologically relevant insights into KLF2-mediated modulation of these inflammatory processes that could potentially be manipulated for therapeutic gain.