Effects of interleukin-15 on autophagy regulation in the skeletal muscle of mice.

This study aimed to evaluate the role of skeletal muscle-derived interleukin (IL)-15 in the regulation of skeletal muscle autophagy using IL-15 knockout (KO) and transgenic (TG) mice. Male C57BL/6 wild-type (WT), IL-15 KO, and IL-15 TG mice were used in this study. Changes in muscle mass, forelimb grip strength, succinate dehydrogenase (SDH) activity, gene and protein expression levels of major regulators and indicators of autophagy, comprehensive gene expression, and DNA methylation in the gastrocnemius muscle were analyzed. Enrichment pathway analyses revealed that the pathology of IL-15 gene deficiency was related to the autophagosome pathway. Moreover, although IL-15 KO mice maintained gastrocnemius muscle mass, they exhibited a decrease in autophagy induction. IL-15 TG mice exhibited a decrease in gastrocnemius muscle mass and an increase in forelimb grip strength and SDH activity in skeletal muscle. In the gastrocnemius muscle, the ratio of phosphorylated adenosine monophosphate-activated protein kinase α (AMPKα) to total AMPKα and unc-51-like autophagy activating kinase 1 and Beclin1 protein expression were higher in the IL-15 TG group than in the WT group. IL-15 gene deficiency induces a decrease in autophagy induction. In contrast, IL-15 overexpression could improve muscle quality by activating autophagy induction while decreasing muscle mass. The regulation of IL-15 in autophagy in skeletal muscles may lead to the development of therapies for the autophagy-induced regulation of skeletal muscle mass and cellular quality control.NEW & NOTEWORTHY IL-15 gene deficiency can decrease autophagy induction. However, although IL-15 overexpression induced a decrease in muscle mass, it led to an improvement in muscle quality. Based on these results, understanding the role of IL-15 in regulating autophagy pathways within skeletal muscle may lead to the development of therapies for the autophagy-induced regulation of skeletal muscle mass and cellular quality control.

Preoperative Comprehensive Geriatric Assessment Predicts Postoperative Risk in Older Patients with Esophageal Cancer.

BACKGROUND: Preoperative risk assessment is important in older patients because they often have comorbidities and impaired organ function. We performed preoperative comprehensive geriatric assessment (CGA) for older patients with esophageal cancer. PATIENTS AND METHODS: A total of 217 patients over 75 years old who underwent esophagectomy for thoracic esophageal cancer were analyzed. The CGA was performed preoperatively and included the Mini-Mental State Examination (MMSE), Geriatric Depression Score (GDS), vitality index, Barthel index, and instrumental activities of daily living (IADL). We defined the robust group as patients with normal function on every instrument, and the pre-frail and frail groups as those with functional impairment on one instrument or two or more instruments, respectively. We assessed how the CGA correlated with postoperative complications and prognosis. RESULTS: Of the 217 patients, 86 (39.6%) were in the robust group, 68 (31.3%) in the pre-frail group, and 63 (29.0%) in the frail group. Postoperative pneumonia (P = 0.026) and anastomotic leakage (P = 0.032) were significantly more common in the frail group. The frail group had a significantly longer postoperative hospitalization period (P = 0.016) and significantly lower rate of discharge to home (P = 0.016). Overall survival (OS) was significantly worse in the frail group (5-year overall survival rate, frail group versus others, 37.8% versus 52.0%, P = 0.046), but it was not significant on multivariate analysis. CONCLUSIONS: The preoperative CGA in older patients with esophageal cancer was associated with risk of postoperative complications.

Factors associated with weight loss by age among community-dwelling older people.

BACKGROUND: Factors associated with weight loss in community-dwelling older people have been reported in several studies, but few studies have examined factors associated with weight loss by age groups. The purpose of this study was to clarify factors associated with weight loss by age in community-dwelling older people through a longitudinal study. METHODS: Participants in the SONIC study (Longitudinal Epidemiological Study of the Elderly) were community-dwelling people aged 70 or older. The participants were divided into two groups: 5% weight loss and maintenance groups, and compared. In addition, we examined factors affecting weight loss by age. The analysis method used was the χ2 test, and the t-test was used for comparison of the two groups. Factors associated with 5% weight loss at 3 years were examined using logistic regression analysis with sex, age, married couple, cognitive function, grip strength, and the serum albumin level as explanatory variables. RESULTS: Of the 1157 subjects, the proportions showing 5% weight loss after 3 years among all subjects, those aged 70 years, 80 years, and 90 years, were 20.5, 13.8, 26.8, and 30.5%, respectively. In logistic regression analysis, factors associated with 5% weight loss at 3 years by age were influenced by BMI of 25 or higher (OR = 1.90, 95%CI = 1.08-3.34, p = 0.026), a married couple (OR = 0.49, 95% = 0.28-0.86, p = 0.013), serum albumin level below 3.8 g/dL (OR = 10.75, 95% = 1.90-60.73, p = 0.007) at age 70, and the grip strength at age 90 (OR = 1.24, 95%CI = 1.02-1.51, p = 0.034), respectively. CONCLUSIONS: The results suggest that factors associated with weight loss by age in community-dwelling older people through a longitudinal study differ by age. In the future, this study will be useful to propose effective interventions to prevent factors associated with weight loss by age in community-dwelling older people.

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.

[Relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus: The SONIC study].

AIM: The purpose of this study was to examine the relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus (DM) from insights that contribute to the management of diabetes in consideration of quality of life (QOL). METHODS: We used the data of the Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC) study, a prospective cohort study of community-dwelling older people. The present study included 2,051 older subjects of 70±1 years, 80±1 years and 90±1 years of age. We conducted medical interviews, blood sampling, and the subjects were asked to complete a questionnaire (WHO-5-J) at the venue. Three hundred sixty-eight people were diagnosed with DM. The subjects of this study were 192 people who were undergoing drug therapy for glycemic control. A multiple regression analysis was performed to clarify the relationship between glycemic control (divided as follows: HbA1c<7.0%, good control group; HbA1c≥7.0%, poor control group) and the WHO-5-J score, as the dependent variable, after adjusting for any confounding factors. RESULTS: In subjects of 70 years of age, a negative association was found between glycemic control and the WHO-5-J score, with the good control group showing a significantly lower score (ß: -0.468, p<0.01) in comparison to the poor control group. In detail, we observed a significant difference in the sub-items of WHO-5-J, question item 3, "I have felt active and vigorous" at 70 years of age (good control group, 2.56±1.37; poor control group, 3.21±1.18; p=0.021) and question item 5, "My daily life has been filled with things that interest me" (good control group, 2.44±1.21; poor control group, 3.11±1.11; p=0.009). As for the two questions, the WHO-5-J scores were lower in the good control group. These associations showed no statistical significance at 80 years of age or 90 years of age. CONCLUSION: The results obtained in this study indicated that strict glycemic control management of diabetes mellitus may lead to a lower mental QOL in younger elderly individuals (70 years of age). Therefore, it is important to pay attention to the mental burdens of the management of glycemic control in older people with DM.

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.

Physical performance reference values for Japanese oldest old: a SONIC study.

BACKGROUND: The oldest old, defined as those aged 90 or over, is now the fastest-growing population sector. This study aimed to determine reference values for several physical performance measures (PPMs) among 90-year-olds using internationally standardized measurements and to clarify the characteristics of these indices by comparing their results for 90-year-olds with those for older people 70 and 80. METHODS: We used the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians (SONIC) study data from 2010 to 2018. The study subjects were 70, 80, and 90-year-olds in the target area eligible to participate in the venue. Excluding those certified for long-term care, the final number of eligible persons is 70s cohort 1000 (2010), 80s cohort 973 (2011), and 90s cohort 690. 90s cohort only consisted of three survey waves: 2012, 2015, and 2018. We used hand grip strength and score on the Short Physical Performance Battery (SPPB) for our physical performance measurements. In addition, we statistically analyzed sex and age differences. RESULT: The simple mean ± standard deviation (SD) for the 90-year-old respondents were in men, 24.1 ± 5.4 kg in hand grip strength, 0.80 ± 0.22 m/s in usual gait speed, 17.2 ± 6.73 s in 5times chair stand, 5.89 ± 4.42 s in tandem balance, and 8.3 ± 2.2 in SPPB respectively and in women, 14.4 ± 4.0 kg in hand grip strength, 0.72 ± 0.20 m/s in usual gait speed, 17.8 ± 7.89 s in 5times chair stand, 4.72 ± 4.35 s in tandem balance, and 7.5 ± 2.4 in SPPB, respectively. For all PPMs, the age 90 cohort was statistically significantly different from the age 70 and 80 cohorts (all trends P <  0.001). Hand grip strength decreased with a similar gradient with age cohort increase of 10 years for both sexes. In contrast, SPPB lower limb score showed a larger drop between the age 80 and 90 cohorts than between the age 70 and 80 cohorts. We also constructed sex-specific appraisal standards according to quintiles. CONCLUSIONS: Our study yielded inclusive sex-specific reference values and appraisal standards for major physical performance measures not certified as requiring long-term care, community-dwelling, oldest old Japanese. The characteristics of age-related decline in physical performance differed between the upper and lower extremity assessments.

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.

Differential effects of pre-exercise on cancer cachexia-induced muscle atrophy in fast- and slow-twitch muscles.

We hypothesized that pre-exercise may effectively prevent cancer cachexia-induced muscle atrophy in both fast- and slow-twitch muscle types. Additionally, the fast-twitch muscle may be more affected by cancer cachexia than slow-twitch muscle. This study aimed to evaluate the effects of pre-exercise on cancer cachexia-induced atrophy and on atrophy in fast- and slow-twitch muscles. Twelve male Wistar rats were randomly divided into sedentary and exercise groups, and another 24 rats were randomly divided into control, pre-exercise, cancer cachexia induced by intraperitoneal injections of ascites hepatoma AH130 cells, and pre-exercise plus cancer cachexia groups. We analyzed changes in muscle mass and in gene and protein expression levels of major regulators and indicators of muscle protein degradation and synthesis pathways, angiogenic factors, and mitochondrial function in both the plantaris and soleus muscles. Pre-exercise inhibited muscle mass loss, rescued protein synthesis, prevented capillary regression, and suppressed hypoxia in the plantaris and soleus muscles. Pre-exercise inhibited mitochondrial dysfunction differently in fast- and slow-twitch muscles. These results suggested that pre-exercise has the potential to inhibit cancer-cachexia-induced muscle atrophy in both fast- and slow-twitch muscles. Furthermore, the different progressions of cancer-cachexia-induced muscle atrophy in fast- and slow-twitch muscles are related to differences in mitochondrial function.

Association of periodontal disease with atherosclerosis in 70-year-old Japanese older adults.

Periodontal disease and arteriosclerotic disease are greatly affected by aging. In this study, the association of conventional risk factors and periodontal disease with atherosclerosis was longitudinally examined in Japanese older adults. Subjects in this study were 490 community-dwelling septuagenarians (69-71 years) randomly recruited from the Basic Resident Registry of urban or rural areas in Japan. At the baseline examination, all subjects underwent socioeconomic and medical interviews; medical examinations, including examinations for carotid atherosclerosis, hypertension, diabetes mellitus, and dyslipidemia; and conventional dental examinations, including a tooth count and measurement of probing pocket depth (PPD). After 3 years, 182 septuagenarians who had no atherosclerosis at the baseline examination were registered and received the same examination as at the baseline. In the re-examination conducted 3 years after the baseline survey, 131 (72.0%) of the 182 participants who had no atherosclerosis at the baseline examination were diagnosed with carotid atherosclerosis. Adjusting and analyzing the mutual relationships of the conventional risk factors for atherosclerosis by multiple logistic regression analysis for the 171 septuagenarians with a full set of data, the proportion of teeth with PPD ≥ 4 mm was independently related to the prevalence of atherosclerosis (odds ratio: 1.029, P < 0.022). This longitudinal study of Japanese older adults suggests that periodontal disease is associated with the onset/progression of atherosclerosis. Maintaining a healthy periodontal condition may be an important factor in preventing the development and progression of atherosclerosis.

[Decrease in activity and its related factors under COVID-19 crisis in community-dwelling older people].

AIM: To prevent the transmission of the novel coronavirus [COVID-19] and stop its spread, a state of emergency was declared from April to May 2020. People were encouraged to refrain from outings and reduce their contact with people. The purpose of this study was to examine the subjective changes in the amount of activity under COVID-19 crisis among the elderly and the factors related to this decrease in activity. METHODS: This study was part of the SONIC study, an ongoing prospective cohort study targeting community dwelling older people in their 70, 80, 90s, and over 100 years old in different regions (urban and suburban) of Japan. Subjective changes in the amount of activity during the state of emergency were assessed via a mail questionnaire. RESULTS: The percentage decrease in activity for the subjects in their 70s, 80s, and 90s were 68.1% (513/753), 65.3% (324/496), and 56.0% (164/293), respectively. By region, 69.4% in urban, while 57.7% in the suburbs. In the 70- and 80-year-old cohorts, the decrease in activity was more frequent among those in urban areas than in suburban areas. In the 90-year-old cohort, the differences between the regions were attenuated, while the economic status and walking speed were significantly associated with a decrease in activity. CONCLUSIONS: The decrease in activity varied by age group and region, suggesting that approaches to preventing the adverse health effects associated with inactivity due to the COVID-19 crisis are more important in urban areas than in suburban ones.

Obesity predicts persistence of resistant hypertension after surgery in patients with primary aldosteronism.

OBJECTIVE: Primary aldosteronism (PA) is considered a major cause of resistant hypertension (RHT). The prevalence of RHT has been recently reported to reach 18% in general hypertension. However, little is known about the prevalence and the outcomes after adrenalectomy of RHT in PA. Therefore, we aimed to clarify the prevalence and surgical outcomes in patients with both PA and RHT. PATIENTS AND DESIGN: Among 550 patients who underwent adrenalectomy for unilateral PA in the Japan PA Study, RHT was defined as an uncontrolled blood pressure (≥140/90 mm Hg) despite treatment with at least any three antihypertensives or hypertension controlled with at least four drugs. Surgical outcome was assessed by the biochemical and clinical outcome. RESULTS: Although 40 (7.3%) patients fulfilled the criteria for preoperative RHT, this should be underestimated because only 36% of patients with postoperative RHT were classified as having preoperative RHT. The prevalence of preoperative RHT was approximately 20% when estimated using the total number of patients with postoperative RHT and the ratio of postoperative RHT in patients with preoperative RHT. Although an improvement in hypertension was achieved in approximately 80% of patients with preoperative RHT, 20% of these exhibited persistent RHT. These patients were more obese than those for whom RHT improved after surgery. Notably, body mass index of ≥25 kg/m2 was an independent predictor of postoperative RHT. CONCLUSIONS: The prevalence of RHT in PA was lower than expected even with the adjustment for underestimation. Furthermore, obesity is an independent factor predicting the postoperative persistence of RHT.

Preventive effects of low-intensity exercise on cancer cachexia-induced muscle atrophy.

We hypothesized that low-intensity endurance exercise might be more effective in preventing cancer cachexia-induced muscle atrophy through both an increase in protein synthesis and a decrease in protein degradation. The purpose of present study was to evaluate the effects and to clarify the mechanism of low-intensity endurance exercise on cancer cachexia-induced muscle atrophy. Twenty-four male Wistar rats were randomly divided into 4 groups: control (Cont), Cont plus exercise (Ex), AH130-induced cancer cachexia (AH130), and AH130 plus Ex. Cancer cachexia was induced by intraperitoneal injections with AH130 Yoshida ascites hepatoma cells; we analyzed the changes in muscle mass and the gene and protein expression levels of major regulators or indicators of skeletal muscle protein degradation and synthesis pathway in the soleus muscles. Low-intensity exercise inhibited the muscle mass loss through a suppression of the ubiquitin-proteasome pathway, increased hypoxia-inducible factor- 1α and phosphorylated AMPK, and inhibited the deactivation of mammalian target of rapamycin pathway in the soleus muscle, which contributed to the prevention of cancer cachexia-induced muscle atrophy. These results suggest that low-intensity exercise has the potential to become an effective therapeutic intervention for the prevention of cancer cachexia-induced muscle atrophy.-Tanaka, M., Sugimoto, K., Fujimoto, T., Xie, K., Takahashi, T., Akasaka, H., Kurinami, H., Yasunobe, Y., Matsumoto, T., Fujino, H., Rakugi, H. Preventive effects of low-intensity exercise on cancer cachexia-induced muscle atrophy.

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.

[Time-sparing screening method for mild cognitive impairment and early Alzheimer's disease: Self- and family reports using the TMIG index of competence].

AIM: To verify the clinical utility of instrumental activities of daily life evaluated using the Tokyo Metropolitan Institute of Gerontology index of competence (TMIG-IC) as a screening tool for patients with early-phase cognitive impairment, including mild cognitive impairment (MCI) and early Alzheimer's disease (AD). METHODS: We recruited healthy subjects from our community-based cohort and consecutive subjects with MCI and AD from our clinic. The TMIG-IC was investigated in all participants and their family members. The total and subscale scores were compared among all groups. We then statistically determined the accuracy of the differentiation of MCI and AD. RESULTS: We registered 187 normal controls (NC), 39 participants with MCI, 50 AD patients with functional assessment staging (FAST) 4, and 19 AD patients with ≥5 FAST. The family-report score was significantly lower in MCI patients than in others, followed by AD patients. The total score was able to differentiate MCI and AD with a sensitivity of 85.7% and a specificity of 90.9% (area under the curve [AUC]=0.913). Differentiation of MCI alone had a low accuracy (AUC=0.787). However, the AUC was 0.847 when only the items with inconsistent responses between self and family reports were used as indices. CONCLUSIONS: The TMIG-IC is a useful tool for evaluating the severity of AD, including early AD. These findings suggest that family-report scores can differentiate MCI and AD from cognitive normal aging with a sufficient degree of accuracy. It was also suggested that inconsistencies between self and family reports were higher when differentiating MCI than the self- and family-reports.

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.