New mechanism leading to alleviation of salt-sensitive hypertension by a powerful angiotensin receptor blocker, azilsartan

Hypertension is one of the most life-threatening health problems in the modern world. Particularly, salt-sensitive hypertension is often associated with cardiovascular disease and defects in the circadian rhythm of the blood pressure. To date, the effects of angiotensin receptor blocker (ARB) against salt sensitivity and the blood pressure’s circadian rhythm have been obscure. A strong ARB, azilsartan, was previously reported to improve the circadian rhythm of blood pressure in hypertensive patients. In a recently published study, we investigated the mechanism by which azilsartan brought about this reaction. We speculated that azilsartan modulated sodium transporters located in the renal tubules because the circadian rhythm of blood pressure is linked to salt handling in the kidney. We discovered that one sodium transporter, NHE3 protein, in the proximal tubules was greatly attenuated in the kidneys of 5/6 nephrectomized mice that had been treated with azilsartan, although the expression of other sodium transporter proteins remained unchanged. The genetic expression of NHE3, however, was not changed by azilsartan. In a subsequent in vitro study using OKP cells, we found that NHE3 protein reduction was induced by enhanced protein degradation by proteasomes, not lysosomes, leading to enhanced sodium excretion. It is suggested that diminished salt sensitivity in the 5/6 nephrectomized mice treated with azilsartan was due to a change in sodium handling induced by the reduction of NHE3 protein in the proximal tubules. These mechanisms underlying the decreased salt sensitivity by azilsartan treatment may lead to totally new drug discoveries

Promoter Polymorphism of RGS2 Gene Is Associated with Change of Blood Pressure in Subjects with Antihypertensive Treatment: The Azelnidipine and Temocapril in Hypertensive Patients with Type 2 Diabetes Study

We performed a prospective study to examine the genetic effect on the response to a calcium (Ca) channel blocker, azelnidipine and an ACE inhibitor, temocapril treatment in patients with hypertension, as a part of the prior clinical trial, the Azelnidipine and Temocapril in Hypertensive Patients with Type 2 Diabetes Study (ATTEST). Methods and Results. All subjects who gave informed consent for genetic research were divided into two groups: the subjects treated with azelnidipine or temocapril, for 52 weeks. We selected 18 susceptible genes for hypertension and determined their genotypes using TaqMan PCR method. RNA samples were extracted from peripheral blood, and quantitative real time PCR for all genes was performed using TaqMan method. One of the polymorphisms of the RGS2 gene was extracted as being able to influence the effect of these treatments to reduce BP. At eight weeks, BP change showed a significant interaction between the A-638G polymorphism of Regulator of G protein signaling-2 (RGS2) gene and treatment with azelnidipine or temocapril. There was no gene whose expression was associated with BP phenotypes or the polymorphisms of each gene. Conclusions. A-638G polymorphism of the RGS-2 gene could be a predictive factor for therapeutic performance of Ca channel blockers

Helicobacter cinaedi-associated Carotid Arteritis

A 65-year-old Japanese man with bilateral carotid atherosclerosis presented with right neck pain and fever. Contrast-enhanced computed tomography suggested carotid arteritis, and carotid ultrasonography showed an unstable plaque. The patient developed a cerebral embolism, causing a transient ischemic attack. Helicobacter cinaedi was detected in blood culture, and H. cinaedi-associated carotid arteritis was diagnosed. Empirical antibiotic therapy was administered for 6 weeks. After readmission for recurrent fever, he was treated another 8 weeks. Although the relationship between H. cinaedi infection and atherosclerosis development remains unclear, the atherosclerotic changes in our patient’s carotid artery might have been attributable to H. cinaedi infection

Glycemic Control and Insulin Improve Muscle Mass and Gait Speed in Type 2 Diabetes: The MUSCLES-DM Study

Ken Sugimoto, Hiroshi Ikegami, Yasunori Takata, Tomohiro Katsuya, Masahiro Fukuda, Hiroshi Akasaka, Yasuharu Tabara, Haruhiko Osawa, Yoshihisa Hiromine, Hiromi Rakugi, Glycemic Control and Insulin Improve Muscle Mass and Gait Speed in Type 2 Diabetes: The MUSCLES-DM Study, Journal of the American Medical Directors Association, 2020, https://doi.org/10.1016/j.jamda.2020.11.003

Fall-related mortality trends in older Japanese adults aged ≥65 years : a nationwide observational study

Objectives Fall-related mortality among older adults is a major public health issue, especially for ageing societies. This study aimed to investigate current trends in fall-related mortality in Japan using nationwide population-based data covering 1997–2016. Design We analysed fall-related deaths among older persons aged ≥65 years using the data provided by the Japanese Ministry of Health, Labour and Welfare. Results The crude and age-standardised mortality rates were calculated per 100 000 persons by stratifying by age (65–74, 75–84 and ≥85 years) and sex. To identify trend changes, a joinpoint regression model was applied by estimating change points and annual percentage change (APC). The total number of fall-related deaths in Japan increased from 5872 in 1997 to 8030 in 2016, of which 78.8% involved persons aged ≥65 years. The younger population (65–74 years) showed continuous and faster-decreasing trends for both men and women. Average APC among men aged ≥75 years did not decrease. Among middle-aged and older women (75–84 and ≥85 years) decreasing trends were observed. Furthermore, the age-adjusted mortality rate of men was approximately twice that of women, and it showed a faster decrease for women. Conclusions Although Japanese healthcare has shown improvement in preventing fall-related deaths over the last two decades, the crude mortality for those aged over 85 years remains high, indicating difficulty in reducing fall-related deaths in the super-aged population. Further investigations to uncover causal factors for falls in older populations are required

Fall-related mortality trends in older Japanese adults aged >= 65 years: a nationwide observational study

OBJECTIVES: Fall-related mortality among older adults is a major public health issue, especially for ageing societies. This study aimed to investigate current trends in fall-related mortality in Japan using nationwide population-based data covering 1997-2016. DESIGN: We analysed fall-related deaths among older persons aged ≥65 years using the data provided by the Japanese Ministry of Health, Labour and Welfare. RESULTS: The crude and age-standardised mortality rates were calculated per 100 000 persons by stratifying by age (65-74, 75-84 and ≥85 years) and sex. To identify trend changes, a joinpoint regression model was applied by estimating change points and annual percentage change (APC). The total number of fall-related deaths in Japan increased from 5872 in 1997 to 8030 in 2016, of which 78.8% involved persons aged ≥65 years. The younger population (65-74 years) showed continuous and faster-decreasing trends for both men and women. Average APC among men aged ≥75 years did not decrease. Among middle-aged and older women (75-84 and ≥85 years) decreasing trends were observed. Furthermore, the age-adjusted mortality rate of men was approximately twice that of women, and it showed a faster decrease for women. CONCLUSIONS: Although Japanese healthcare has shown improvement in preventing fall-related deaths over the last two decades, the crude mortality for those aged over 85 years remains high, indicating difficulty in reducing fall-related deaths in the super-aged population. Further investigations to uncover causal factors for falls in older populations are required

Malt1-Induced Cleavage of Regnase-1 in CD4+ Helper T Cells Regulates Immune Activation

SummaryRegnase-1 (also known as Zc3h12a and MCPIP1) is an RNase that destabilizes a set of mRNAs, including Il6 and Il12b, through cleavage of their 3′ UTRs. Although Regnase-1 inactivation leads to development of an autoimmune disease characterized by T cell activation and hyperimmunoglobulinemia in mice, the mechanism of Regnase-1-mediated immune regulation has remained unclear. We show that Regnase-1 is essential for preventing aberrant effector CD4+ T cell generation cell autonomously. Moreover, in T cells, Regnase-1 regulates the mRNAs of a set of genes, including c-Rel, Ox40, and Il2, through cleavage of their 3′ UTRs. Interestingly, T cell receptor (TCR) stimulation leads to cleavage of Regnase-1 at R111 by Malt1/paracaspase, freeing T cells from Regnase-1-mediated suppression. Furthermore, Malt1 protease activity is critical for controlling the mRNA stability of T cell effector genes. Collectively, these results indicate that dynamic control of Regnase-1 expression in T cells is critical for controlling T cell activation

Apop-1, a Novel Protein Inducing Cyclophilin D-dependent but Bax/Bak-related Channel-independent Apoptosis

In the intrinsic pathway of apoptosis, mitochondria play a crucial role by releasing cytochrome c from the intermembrane space into the cytoplasm. Cytochrome c release through Bax/Bak-dependent channels in mitochondria has been well documented. In contrast, cyclophilin D (CypD), an important component of permeability transition pore-dependent protein release, remains largely undefined, and no apoptogenic proteins that act specifically in a CypD-dependent manner have been reported to date. Here, we describe a novel and evolutionarily conserved protein, apoptogenic protein (Apop). Mouse Apop-1 expression induces apoptotic death by releasing cytochrome c from mitochondria into the cytosolic space followed by activation of caspase-9 and -3. Apop-1-induced apoptosis is not blocked by Bcl-2 or Bcl-xL, inhibitors of Bax/Bak-dependent channels, whereas it is completely blocked by cyclosporin A, an inhibitor of permeability transition pore. Cells lacking CypD were resistant to Apop-induced apoptosis. Moreover, inhibition of Apop expression prevented the cell death induced by apoptosis-inducing substances. Our findings, thus, indicate that the expression of Apop-1 induces apoptosis though CypD-dependent pathway and that Apop-1 plays roles in cell death under physiological conditions

Timp-3 deficiency impairs cognitive function in mice

Extracellular matrix (ECM) degradation is performed primarily by matrix metalloproteinases (MMPs). MMPs have recently been shown to regulate synaptic activity in the hippocampus and to affect memory and learning. The tissue inhibitor of metalloproteinase (Timp) is an endogenous factor that controls MMP activity by binding to the catalytic site of MMPs. At present, four Timp isotypes have been reported (Timp-1 through Timp-4) with 35–50% amino-acid sequence homology. Timp-3 is a unique member of Timp proteins in that it is bound to the ECM. In this study, we used the passive avoidance test, active avoidance test, and water maze test to examine the cognitive function in Timp-3 knockout (KO) mice. Habituation was evaluated using the open-field test. The water maze test showed that Timp-3 KO mice exhibit deterioration in cognitive function compared with wild-type (WT) mice. The open-field test showed decreased habituation of Timp-3 KO mice. Immunostaining of brain slices revealed the expression of Timp-3 in the hippocampus. In situ zymography of the hippocampus showed increased gelatinolytic activity in Timp-3 KO mice compared with WT mice. These results present the first evidence of Timp-3 involvement in cognitive function and hippocampal MMP activity in mice. Moreover, our findings suggest a novel therapeutic target to be explored for improvement of cognitive function in humans

Variantes genéticas en el locus 9p21 contribuyen al desarrollo de arteriosclerosis a través de la modulación de ANRIL y CDKN2A/B

Registro creado en correspondencia al grado de doctora de Ada Congrains Castillo.Los estudios de asociación de todo el genoma (GWAS) han identificado variantes genéticas que contribuyen al riesgo de enfermedad cardiovascular (ECV) en el locus del cromosoma 9p21. La región asociada a CVD es adyacente a los dos inhibidores de quinasas dependientes de ciclina (CDKN) 2A y 2B y los últimos exones del ARN no codificante, ANRIL. Todavía no está claro cuál de estas transcripciones o cómo están involucradas en la patogénesis de la aterosclerosis.Genome-wide association studies (GWAS) have identified genetic variants contributing to the risk of cardiovascular disease (CVD) at the chromosome 9p21 locus. The CVD-associated region is adjacent to the two cyclin dependent kinase inhibitors (CDKN)2A and 2B and the last exons of the non-coding RNA, ANRIL. It is still not clear which of or how these transcripts are involved in the pathogenesis of atherosclerosis.Japón. Programa de Promoción de Estudios Fundamentales en el Instituto Nacional de Innovación Biomédica de Japón (HR: 22-2-5), el Ministerio de Educación, Cultura, Deportes, Ciencia y Tecnología de Japón (KK: 22510211) y la Fundación NOVARTIS para la Investigación Gerontológica (KK).Tesi