Phase I Study to Assess the Safety and Immunogenicity of an Intradermal COVID-19 DNA Vaccine Administered Using a Pyro-Drive Jet Injector in Healthy Adults.

We conducted a nonrandomized, open-label phase I study to assess the safety and immunogenicity of an intradermal coronavirus disease 2019 (COVID-19) DNA vaccine (AG0302-COVID-19) administered using a pyro-drive jet injector at Osaka University Hospital between Yanagida November 2020 and December 2021. Twenty healthy volunteers, male or female, were enrolled in the low-dose (0.2 mg) or high-dose (0.4 mg) groups and administered AG0302-COVID19 twice at a 2-week interval. There were no adverse events that led to discontinuation of the study drug vaccination schedule. A serious adverse event (disc protrusion) was reported in one patient in the high-dose group, but the individual recovered, and the adverse event was not causally related to the study drug. In the analysis of the humoral immune response, the geometric mean titer (GMT) of serum anti-SARS-CoV-2 spike glycoprotein-specific antibody was low in both the low-dose and high-dose groups (246.2 (95% CI 176.2 to 344.1, 348.2 (95% CI 181.3 to 668.9)) at the 8 weeks after first vaccination. Regarding the analysis of the cellular immune, the number of IFN-γ-producing cells responsive to the SARS-CoV-2 spike glycoprotein increased with individual differences after the first dose and was sustained for several months. Overall, no notable safety issues were observed with the intradermal inoculations of AG0302-COVID19. Regarding immunogenicity, a cellular immune response was observed in some subjects after AG0302-COVID19 intradermal inoculation, but no significant antibody production was observed.

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.

Double Deletion of Angiotensin II Type 2 and Mas Receptors Accelerates Aging-Related Muscle Weakness in Male Mice.

Background The activation of AT2 (angiotensin II type 2 receptor ) and Mas receptor by angiotensin II and angiotensin-(1-7), respectively, is the primary process that counteracts activation of the canonical renin-angiotensin system (RAS). Although inhibition of canonical RAS could delay the progression of physiological aging, we recently reported that deletion of Mas had no impact on the aging process in mice. Here, we used male mice with a deletion of only AT2 or a double deletion of AT2 and Mas to clarify whether these receptors contribute to the aging process in a complementary manner, primarily by focusing on aging-related muscle weakness. Methods and Results Serial changes in grip strength of these mice up to 24 months of age showed that AT2/Mas knockout mice, but not AT2 knockout mice, had significantly weaker grip strength than wild-type mice from the age of 18 months. AT2/Mas knockout mice exhibited larger sizes, but smaller numbers and increased frequency of central nucleation (a marker of aged muscle) of single skeletal muscle fibers than AT2 knockout mice. Canonical RAS-associated genes, inflammation-associated genes, and senescence-associated genes were highly expressed in skeletal muscles of AT2/Mas knockout mice. Muscle angiotensin II content increased in AT2/Mas knockout mice. Conclusions Double deletion of AT2 and Mas in mice exaggerated aging-associated muscle weakness, accompanied by signatures of activated RAS, inflammation, and aging in skeletal muscles. Because aging-associated phenotypes were absent in single deletions of the receptors, AT2 and Mas could complement each other in preventing local activation of RAS during aging.

RAGE ligands stimulate angiotensin II type I receptor (AT1) via RAGE/AT1 complex on the cell membrane.

The receptor for advanced glycation end-products (RAGE) and the G protein-coupled angiotensin II (AngII) type I receptor (AT1) play a central role in cardiovascular diseases. It was recently reported that RAGE modifies AngII-mediated AT1 activation via the membrane oligomeric complex of the two receptors. In this study, we investigated the presence of the different directional crosstalk in this phenomenon, that is, the RAGE/AT1 complex plays a role in the signal transduction pathway of RAGE ligands. We generated Chinese hamster ovary (CHO) cells stably expressing RAGE and AT1, mutated AT1, or AT2 receptor. The activation of two types of G protein α-subunit, Gq and Gi, was estimated through the accumulation of inositol monophosphate and the inhibition of forskolin-induced cAMP production, respectively. Rat kidney epithelial cells were used to assess RAGE ligand-induced cellular responses. We determined that RAGE ligands activated Gi, but not Gq, only in cells expressing RAGE and wildtype AT1. The activation was inhibited by an AT1 blocker (ARB) as well as a RAGE inhibitor. ARBs inhibited RAGE ligand-induced ERK phosphorylation, NF-κB activation, and epithelial-mesenchymal transition of rat renal epithelial cells. Our findings suggest that the activation of AT1 plays a central role in RAGE-mediated cellular responses and elucidate the role of a novel molecular mechanism in the development of cardiovascular diseases.

The endocytosis of oxidized LDL via the activation of the angiotensin II type 1 receptor.

Arrestin-dependent activation of a G-protein-coupled receptor (GPCR) triggers endocytotic internalization of the receptor complex. We analyzed the interaction between the pattern recognition receptor (PRR) lectin-like oxidized low-density lipoprotein (oxLDL) receptor (LOX-1) and the GPCR angiotensin II type 1 receptor (AT1) to report a hitherto unidentified mechanism whereby internalization of the GPCR mediates cellular endocytosis of the PRR ligand. Using genetically modified Chinese hamster ovary cells, we found that oxLDL activates Gαi but not the Gαq pathway of AT1 in the presence of LOX-1. Endocytosis of the oxLDL-LOX-1 complex through the AT1-ß-arrestin pathway was demonstrated by real-time imaging of the membrane dynamics of LOX-1 and visualization of endocytosis of oxLDL. Finally, this endocytotic pathway involving GPCR kinases (GRKs), ß-arrestin, and clathrin is relevant in accumulating oxLDL in human vascular endothelial cells. Together, our findings indicate that oxLDL activates selective G proteins and ß-arrestin-dependent internalization of AT1, whereby the oxLDL-LOX-1 complex undergoes endocytosis.

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.

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.

Serum albumin/globulin ratio is associated with cognitive function in community-dwelling older people: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study.

AIM: The objective of this study was to clarify the relationship between cognitive function and the serum albumin/globulin ratio (A/G ratio) in community-dwelling Japanese older adults. METHODS: Randomly extracted residents in both urban and rural parts of Japan were enrolled in this study. A total of 1827 participants with a mean age of 70 or 80 years were recruited. A venue survey method was carried out with comprehensive studies, including interviews, blood collection, physical examination and cognitive function tests. RESULTS: Univariate analysis showed a significant positive correlation between the total Japanese version of the Montreal Cognitive Assessment score and the serum A/G ratio at the age of 70 and 80 years, in which better cognitive function was associated with a high serum A/G ratio. Multiple regression analysis with the total Japanese version of the Montreal Cognitive Assessment score as the dependent variable showed that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and sex were related to the Japanese version of the Montreal Cognitive Assessment total score at the age of 70 years, and that the serum albumin level, serum globulin level, serum A/G ratio, C-reactive protein, years of formal education and stroke were related at the age of 80 years. The serum A/G ratio showed a better correlation than the serum globulin levels at the age of 70 and 80 years (70 years: ß = 0.131 vs -0.111, 80 years: ß = 0.108 vs -0.071). CONCLUSIONS: We found a correlation between cognitive function and the serum A/G ratio in community-dwelling older people, suggesting that nutritional status and chronic inflammation might influence cognitive function. Geriatr Gerontol Int 2019; 19: 967-971.

Association between long-term care and chronic and lifestyle-related disease modified by social profiles in community-dwelling people aged 80 and 90; SONIC study.

BACKGROUND: Chronic and lifestyle-related diseases and social status were reported to be associated with long-term care (LTC). The social factors should be treated as social sub-groups of which characteristics show social profiles. However, few previous studies considered that. The present study aimed to investigate the associations between LTC and chronic and lifestyle-related diseases, and whether the associations were modified by the social sub-groups in the community-dwelling elderly. METHOD: A cross-sectional study was conducted among 1004 community-dwelling participants aged 80 and 90. LTC was used as the outcome. Chronic and lifestyle-related diseases (i.e., stroke, heart disease, joint pain, osteoporosis, lung disease, cancer, hypertension, dyslipidemia, and diabetes) were used as the predictors. Education, household income, residential area, and support environment were analyzed by latent class analysis (LCA) to derive social profiles. We obtained odds ratios (ORs) of LTC from those diseases and tested interactions between those diseases and the social profiles by logistic regression analyses. RESULT: The participants were categorized into two sub-groups of social factors (n = 675 and 329) by LCA. Logistic regression analyses showed ORs (95% CI) of LTC were 4.69 (2.49, 8.71) from stroke, 2.22 (1.46, 3.38) from joint pain, 1.99 (1.22, 3.25) from osteoporosis, and 2.05 (1.22, 3.40) from cancer adjusting for the social sub-groups. There were no significant interactions between the social subgroups and those diseases in relation to LTC except for osteoporosis. CONCLUSION: The associations between LTC and chronic and lifestyle-related diseases were significant with adjusting for the social sub-groups, and not modified by that except osteoporosis.

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-converting enzyme 2 deficiency accelerates and angiotensin 1-7 restores age-related muscle weakness in mice.

BACKGROUND: A pharmacologic strategy for age-related muscle weakness is desired to improve mortality and disability in the elderly. Angiotensin-converting enzyme 2 (ACE2) cleaves angiotensin II into angiotensin 1-7, a peptide known to protect against acute and chronic skeletal muscle injury in rodents. Since physiological aging induces muscle weakness via mechanisms distinct from other muscle disorders, the role of ACE2-angiotensin 1-7 in age-related muscle weakness remains undetermined. Here, we investigated whether deletion of ACE2 alters the development of muscle weakness by aging and whether angiotensin 1-7 reverses muscle weakness in older mice. METHODS: After periodic measurement of grip strength and running distance in male ACE2KO and wild-type mice until 24 months of age, we infused angiotensin 1-7 or vehicle for 4 weeks, and measured grip strength, and excised tissues. Tissues were also excised from younger (3-month-old) and middle-aged (15-month-old) mice. Microarray analysis of RNA was performed using tibialis anterior (TA) muscles from middle-aged mice, and some genes were further tested using RT-PCR. RESULTS: Grip strength of ACE2KO mice was reduced at 6 months and was persistently lower than that of wild-type mice (p < 0.01 at 6, 12, 18, and 24-month-old). Running distance of ACE2KO mice was shorter than that of wild-type mice only at 24 months of age [371 ± 26 vs. 479 ± 24 (m), p < 0.01]. Angiotensin 1-7 improved grip strength in both types of older mice, with larger effects observed in ACE2KO mice (% increase, 3.8 ± 1.5 and 13.3 ± 3.1 in wild type and ACE2KO mice, respectively). Older, but not middle-aged ACE2KO mice had higher oxygen consumption assessed by a metabolic cage than age-matched wild-type mice. Angiotensin 1-7 infusion modestly increased oxygen consumption in older mice. There was no difference in a wheel-running activity or glucose tolerance between ACE2KO and wild-type mice and between mice with vehicle and angiotensin 1-7 infusion. Analysis of TA muscles revealed that p16INK4a, a senescence-associated gene, and central nuclei of myofibers increased in middle-aged, but not younger ACE2KO mice. p16INK4a and central nuclei increased in TA muscles of older wild-type mice, but the differences between ACE2KO and wild-type mice remained significant (p < 0.01). Angiotensin 1-7 did not alter the expression of p16INK4a or central nuclei in TA muscles of both types of mice. Muscle ACE2 expression of wild-type mice was the lowest at middle age (2.6 times lower than younger age, p < 0.05). CONCLUSIONS: Deletion of ACE2 induced the early manifestation of muscle weakness with signatures of muscle senescence. Angiotensin 1-7 improved muscle function in older mice, supporting future application of the peptide or its analogues in the treatment of muscle weakness in the elderly population.

High plasma adiponectin levels are associated with frailty in a general old-old population: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study.

AIM: The objective of the present study was to investigate the association between frailty and plasma adiponectin levels in a general population of Japanese older adults. METHODS: The volunteer older adults, aged approximately 83 years, were recruited randomly from a general population in the Japanese Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study. We used the modified Cardiovascular Health Study criteria to assess the frailty status of the study participants. The study participants were classified as non-frail, pre-frail and frail according to their physical activities. We compared plasma adiponectin levels among these three groups and applied a multivariate logistic regression analysis including plasma adiponectin levels to clarify the factors associated with frailty status in the cross-sectional design. RESULTS: The mean age of the participants was 83.1 ± 0.9 years, and 51.8% were men. The frailty index was available to assess 353 participants, of whom 24.6% were classified as non-frail, 62.3% as prefrail and 13.0% as frail. The log-transformed plasma adiponectin levels increased stepwise in the following order: non-frail, pre-frail and frail. A multivariate logistic regression analysis showed that higher plasma adiponectin levels, a higher estimated glomerular filtration rate and lower hemoglobin levels were independent determinants for pre-frail/frail status compared with non-frail status. CONCLUSIONS: The present study showed that higher plasma adiponectin levels were associated with frailty status in older Japanese adults in the general population. Further longitudinal study is essential to clarify the role of plasma adiponectin in the progression of frailty. Geriatr Gerontol Int 2018; 18: 839-846.

A klotho gene single nucleotide polymorphism is associated with the onset of stroke and plasma klotho concentration.

Klotho protects against development of multiple age-related disorders, including cardiovascular diseases. We assessed whether a human klotho single nucleotide polymorphism (SNP) rs650439 is associated with the onset of stroke in hypertensive patients and plasma klotho concentration in the general population. Five hundred and twenty-three patients with hypertension were analyzed for both the presence of rs650439 and onset of stroke. We found that hypertensive patients with the TT genotype of rs650439 (n=52) had a higher incidence of stroke than those with AT (n=257) and AA (n=214) genotypes. Multivariate analysis indicated that the TT genotype was the only risk factor associated with increased incidence of stroke. Plasma klotho concentrations were measured in a general population (age=70±1 years) to assess the association between rs650439 and plasma klotho concentration. A significant trend was observed in the elderly population where plasma klotho concentration decreased as the T alleles in rs650439 increased. Subjects with a TT genotype had lower plasma klotho concentrations than those with AT+AA genotypes. In conclusion, TT genotype of klotho SNP (rs650439) is correlated with an increased incidence of stroke in hypertensive patients, and the mechanism underlying this correlation might involve the effect of rs650439 T allele on plasma klotho concentrations.

Longitudinal association of hypertension and diabetes mellitus with cognitive functioning in a general 70-year-old population: the SONIC study.

Both hypertension and diabetes in middle-aged individuals have been suggested to be predictive indicators of cognitive decline. However, the association of hypertension, diabetes and their combination with cognitive functioning is still controversial in older people. The purpose of this study was to investigate the association between cognitive decline and hypertension, diabetes, and their combination in 70-year-old people based on a 3-year longitudinal analysis. Four hundred and fifty-four people aged 70 (±1) years who participated in the Japanese longitudinal cohort study of Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC) were recruited randomly from a general population and were monitored for 3 years. The data, including most of the demographics, cognitive functioning measured by the Montreal Cognitive Assessment Japanese version (MoCA-J), blood pressure, blood chemistry and other medical histories, were collected at baseline and during the follow-up. The prevalence of hypertension noted in the follow-up survey was significantly higher than than noted at baseline. The mean MoCA-J score at follow-up was not significantly different from the score obtained at baseline. However, the participants with diabetes, especially combined with hypertension at baseline, had significantly lower MoCA-J scores than those without lifestyle-related diseases. The combination of hypertension and diabetes was still a significant risk factor for cognitive decline, considering the MoCA-J scores obtained during the follow-up after adjustments at baseline, relative to sex, body mass index, dyslipidemia, smoking, excessive alcohol intake, antihypertensive treatment and education level (ß=-0.14; P<0.01). Our findings indicate that diabetes and the combination of hypertension and diabetes are clear risk factors for future cognitive decline in elderly individuals who are 70 years of age.

Modified forelimb grip strength test detects aging-associated physiological decline in skeletal muscle function in male mice.

The conventional forelimb grip strength test is a widely used method to assess skeletal muscle function in rodents; in this study, we modified this method to improve its variability and consistency. The modified test had lower variability among trials and days than the conventional test in young C57BL6 mice, especially by improving the variabilities in male. The modified test was more sensitive than the conventional test to detect a difference in motor function between female and male mice, or between young and old male mice. When the modified test was performed on male mice during the aging process, reduction of grip strength manifested between 18 and 24 months of age at the group level and at the individual level. The modified test was similar to the conventional test in detecting skeletal muscle dysfunction in young male dystrophic mice. Thus, the modified forelimb grip strength test, with its improved validity and reliability may be an ideal substitute for the conventional method.

Differences in the association between high blood pressure and cognitive functioning among the general Japanese population aged 70 and 80 years: The SONIC study.

High blood pressure in middle age (up to 64 years) has been proposed as a predictive indicator of dementia. However, the association between hypertension and the cognitive functioning is controversial in older age groups. The aim of this study was to investigate this association in 70-80-year-old participants in the Japanese study of Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC). Participants aged 70 (±1) and 80 (±1) years (n=1000 and 973, respectively) were randomly recruited from the general population in Japan. Cognitive functioning was measured by the Montreal Cognitive Assessment. Blood pressure and other medical and social variables were analyzed by multiple regression analyses. High systolic blood pressure (SBP) was significantly correlated with a reduced cognitive functioning only in participants aged 70 years. Additionally, this correlation became more marked in participants with uncontrolled blood pressure at age 70 years. In contrast, SBP was not significantly correlated with the cognitive functioning at age 80 years. Nutritional status indicators such as serum albumin and frequency of going outdoors were significantly associated with cognitive functioning at age 80 years. Our findings indicate that high SBP has a significant role in cognitive functioning at age 70 years; however, blood pressure is less important as a risk factor for cognitive decline at age 80 years.

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.