Evaluation of glomerular hemodynamic changes by sodium-glucose-transporter 2 inhibition in type 2 diabetic rats using in vivo imaging.

The mechanisms responsible for glomerular hemodynamic regulation with sodium-glucose co-transporter 2 (SGLT2) inhibitors in kidney disease due to type 2 diabetes remain unclear. Therefore, we investigated changes in glomerular hemodynamic function using an animal model of type 2 diabetes, treated with an SGLT2 inhibitor alone or in combination with a renin-angiotensin-aldosterone system inhibitor using male Zucker lean (ZL) and Zucker diabetic fatty (ZDF) rats. Afferent and efferent arteriolar diameter and single-nephron glomerular filtration rate (SNGFR) were evaluated in ZDF rats measured at 0, 30, 60, 90, or 120 minutes after the administration of a SGLT2 inhibitor (luseogliflozin). Additionally, we assessed these changes under the administration of the adenosine A1 receptor (A1aR) antagonist (8-cyclopentyl-1,3-dipropylxanthine), along with coadministration of luseogliflozin and an angiotensin II receptor blocker (ARB), telmisartan. ZDF rats had significantly increased SNGFR, and afferent and efferent arteriolar diameters compared to ZL rats, indicating glomerular hyperfiltration. Administration of luseogliflozin significantly reduced afferent vasodilatation and glomerular hyperfiltration, with no impact on efferent arteriolar diameter. Urinary adenosine levels were increased significantly in the SGLT2 inhibitor group compared to the vehicle group. A1aR antagonism blocked the effect of luseogliflozin on kidney function. Co-administration of the SGLT2 inhibitor and ARB decreased the abnormal expansion of glomerular afferent arterioles, whereas the efferent arteriolar diameter was not affected. Thus, regulation of afferent arteriolar vascular tone via the A1aR pathway is associated with glomerular hyperfiltration in type 2 diabetic kidney disease.

Gait pattern can alter aesthetic visual impression from a third-person perspective.

Beauty is related to our lives in various ways and examining it from an interdisciplinary approach is essential. People are very concerned with their appearance. A widely accepted beauty ideal is that the thinner an individual is, the more beautiful they are. However, the effect of continuous motion on body form aesthetics is unclear. Additionally, an upright pelvic posture in the sagittal plane during walking seems to affect the aesthetic judgments of female appearance. We directly analyzed the influence of body form and walking pattern on aesthetic visual impressions from a third-person perspective with a two-way analysis of variance. Captured motion data for three conditions-upright pelvis, normal pelvis, and posteriorly tilted pelvic posture-were applied to each of three mannequins, representing thin, standard, and obese body forms. When participants watched stimulus videos of the mannequins walking with various postures, a significantly higher score for aesthetic visual impression was noted for an upright pelvic posture than for a posteriorly tilted pelvic posture, irrespective of body form (F(2, 119) = 79.89, p < 0.001, η2 = 0.54). These findings show that the third-person perspective of beauty can be improved even without being thin by walking with an upright pelvic posture.

Activation of the inflammasome drives peritoneal deterioration in a mouse model of peritoneal fibrosis.

During peritoneal dialysis (PD), the peritoneum is exposed to a bioincompatible dialysate, deteriorating the tissue and limiting the long-term effectiveness of PD. Peritoneal fibrosis is triggered by chronic inflammation induced by a variety of stimuli, including peritonitis. Exposure to PD fluid alters peritoneal macrophages phenotype. Inflammasome activation triggers chronic inflammation. First, it was determined whether inflammasome activation causes peritoneal deterioration. In the in vivo experiments, the increased expression of the inflammasome components, caspase-1 activity, and concomitant overproduction of IL-1ß and IL-18 were observed in a mouse model of peritoneal fibrosis. ASC-positive and F4/80-positive cells colocalized in the subperitoneal mesothelial cell layer. These macrophages expressed high CD44 levels indicating that the CD44-positive macrophages contribute to developing peritoneal deterioration. Furthermore, intravital imaging of the peritoneal microvasculature demonstrated that the circulating CD44-positive leukocytes may contribute to peritoneal fibrosis. Bone marrow transplantation in ASC-deficient mice suppressed inflammasome activation, thereby attenuating peritoneal fibrosis in a high glucose-based PD solution-injected mouse model. Our results suggest inflammasome activation in CD44-positive macrophages may be involved in developing peritoneal fibrosis. The inflammasome-derived pro-inflammatory cytokines might therefore serve as new biomarkers for developing encapsulating peritoneal sclerosis.

Evidence for Hypoxia-Induced Shift in ATP Production from Glycolysis to Mitochondrial Respiration in Pulmonary Artery Smooth Muscle Cells in Pulmonary Arterial Hypertension.

BACKGROUND: The metabolic state of pulmonary artery smooth muscle cells (PASMCs) from patients with pulmonary arterial hypertension (PAH) is not well understood. In this study, we examined the balance between glycolysis and mitochondrial respiration in non-PAH-PASMCs and PAH-PASMCs under normoxia and hypoxia. METHODS: We investigated the enzymes involved in glycolysis and mitochondrial respiration, and studied the two major energy-yielding pathways (glycolysis and mitochondrial respiration) by measuring extracellular acidification rate (ECAR) and cellular oxygen consumption rate (OCR) using the Seahorse extracellular flux technology. RESULTS: Under both normoxia and hypoxia, the mRNA and protein levels of pyruvate dehydrogenase kinase 1 and pyruvate dehydrogenase were increased in PAH-PASMCs compared with non-PAH-PASMCs. The mRNA and protein levels of lactate dehydrogenase, as well as the intracellular lactate concentration, were also increased in PAH-PASMCs compared with non-PAH-PASMCs under normoxia. However, these were not significantly increased in PAH-PASMCs compared with non-PAH-PASMCs under hypoxia. Under normoxia, ATP production was significantly lower in PAH-PASMCs (59 ± 5 pmol/min) than in non-PAH-PASMCs (70 ± 10 pmol/min). On the other hand, ATP production was significantly higher in PAH-PASMCs (31 ± 5 pmol/min) than in non-PAH-PASMCs (14 ± 3 pmol/min) under hypoxia. CONCLUSIONS: There is an underlying change in the metabolic strategy to generate ATP production under the challenge of hypoxia.

Posttraumatic Growth as a Process Beginning Before Bereavement: New Perspectives on Theory Development.

Calhoun and Tedeschi's growth model focuses on cognitive processing after bereavement but it does not show the change in life narrative from beforehand. Our qualitative study aimed to clarify bereaved family growth and revealed new perspectives on posttraumatic growth (PTG), including that the PTG process involves a pre-bereavement experience and is not limited to positive psychological changes.Based on the two new perspectives, a discussion of PTG theory reveals that bereaved families' PTG can only be accurately captured if the pre-loss experience is included; thus, Calhoun and Tedeschi's growth model, which only captures the post-loss process, is insufficient. Additionally, positive psychological changes are not the only type of growth. When considering growth, one must focus on the process, including the experience of the person realizing that it is "okay to be who they are."

Growth Experience Bereaved of a Spouse by Cancer: Relying on Merleau-Ponty's Reorganization of the Body Schemes.

The grief experienced by bereaved families can lead to positive changes, and its relevance to the emerging concept of posttraumatic growth has been explored. However, studies on survivors bereaved of a spouse by cancer are scarce; consequently, the nature of growth remains poorly understood. This study aimed to explore the growth experiences of survivors bereaved of a spouse by cancer. Based on Merleau-Ponty's theory of the body, we phenomenologically analyzed narratives/qualitative data collected through interviews of 21 survivors bereaved of a spouse by cancer. The assessment of the growth of survivors bereaved of a spouse by cancer began before the bereavement, with the questioning of habits with the living spouse because of illness and prognosis announcement and/or bereavement, reaffirming the connection with the spouse, realizing that it provides emotional support, and becoming accustomed to who they are now in the new environment.

Pemafibrate Prevents Rupture of Angiotensin II-Induced Abdominal Aortic Aneurysms.

Background: Abdominal aortic aneurysm (AAA) is a life-threatening disease that lacks effective preventive therapies. This study aimed to evaluate the effect of pemafibrate, a selective peroxisome proliferator-activated receptor alpha (PPARα) agonist, on AAA formation and rupture. Methods: Experimental AAA was induced by subcutaneous angiotensin II (AngII) infusion in ApoE - / - mice for 4 weeks. Pemafibrate (0.1 mg/kg/day) was administered orally. Dihydroethidium staining was used to evaluate the reactive oxygen species (ROS). Results: The size of the AngII-induced AAA did not differ between pemafibrate- and vehicle-treated groups. However, a decreased mortality rate due to AAA rupture was observed in pemafibrate-treated mice. Pemafibrate ameliorated AngII-induced ROS and reduced the mRNA expression of interleukin-6 and tumor necrosis factor-α in the aortic wall. Gelatin zymography analysis demonstrated significant inhibition of matrix metalloproteinase-2 activity by pemafibrate. AngII-induced ROS production in human vascular smooth muscle cells was inhibited by pre-treatment with pemafibrate and was accompanied by an increase in catalase activity. Small interfering RNA-mediated knockdown of catalase or PPARα significantly attenuated the anti-oxidative effect of pemafibrate. Conclusion: Pemafibrate prevented AAA rupture in a murine model, concomitant with reduced ROS, inflammation, and extracellular matrix degradation in the aortic wall. The protective effect against AAA rupture was partly mediated by the anti-oxidative effect of catalase induced by pemafibrate in the smooth muscle cells.

Impact of shear wave dispersion slope analysis for assessing the severity of myocarditis.

This study aimed to elucidate the utility of a novel ultrasound-based technique, shear wave dispersion slope (SWDS) analysis, which estimates tissue viscosity, for evaluating the severity of myocardial inflammation. Experimental autoimmune myocarditis (EAM) at different disease phases [3-week (acute phase): n = 10, 5-week (subacute phase): n = 9, and 7-week (late phase): n = 11] were developed in male Lewis rats. SWDS was measured in the right and the left ventricular free walls (RVFW and LVFW) under a retrograde perfusion condition. Histological myocardial inflammation was evaluated by CD68 staining. The accumulation of CD68-positive cells was severe in the myocardium of the EAM 3-week group. The median (interquartile range) SWDS of RVFW was significantly higher in the EAM 3-week group [9.9 (6.5-11.0) m/s/kHz] than in the control group [5.4 (4.5-6.8) m/s/kHz] (P = 0.034). The median SWDS of LVFW was also significantly higher in the EAM 3-week group [8.1 (6.4-11.0) m/s/kHz] than in the control group [4.4 (4.2-4.8) m/s/kHz] (P = 0.003). SWDS and the percentage of CD68-positive area showed a significant correlation in RVFW (R2 = 0.64, P < 0.001) and LVFW (R2 = 0.73, P < 0.001). This study showed that SWDS was elevated in ventricular walls with acute inflammation and also significantly correlated with the degree of myocardial inflammation. These results suggest the potential of SWDS in estimating the histological severity of acute myocarditis.

Efficacy of shear wave elasticity for evaluating myocardial hypertrophy in hypertensive rats.

Shear wave (SW) imaging is a novel ultrasound-based technique for assessing tissue characteristics. SW elasticity may be useful to assess the severity of hypertensive left ventricular (LV) hypertrophy. This study aimed to evaluate the efficacy of SW elasticity for assessing the degree of myocardial hypertrophy using hypertensive rats. Rats were divided into hypertension group and control group. SW elasticity was measured on the excised heart. Myocardial hypertrophy was assessed histologically. LV weight was greater in hypertension group. An increase in interventricular septum and LV free wall thicknesses was observed in hypertension group. SW elasticity was significantly higher in hypertension group than in control group (14.6 ± 4.3 kPa vs. 6.5 ± 1.1 kPa, P < 0.01). The cross-sectional area of cardiomyocytes was larger in hypertension group than in control group (397 ± 50 µm2 vs. 243 ± 14 µm2, P < 0.01), and SW elasticity was positively correlated with the cross-sectional area of cardiomyocytes (R = 0.96, P < 0.01). This study showed that SW elasticity was higher in hypertensive rats and was closely correlated with the degree of myocardial hypertrophy, suggesting the efficacy of SW elasticity for estimating the severity of hypertensive LV hypertrophy.

Endothelial Dysfunction Accelerates Impairment of Mitochondrial Function in Ageing Kidneys via Inflammasome Activation.

Chronic kidney disease is a common problem in the elderly and is associated with increased mortality. We have reported on the role of nitric oxide, which is generated from endothelial nitric oxide synthase (eNOS), in the progression of aged kidneys. To elucidate the role of endothelial dysfunction and the lack of an eNOS-NO pathway in ageing kidneys, we conducted experiments using eNOS and ASC-deficient mice. C57B/6 J mice (wild type (WT)), eNOS knockout (eNOS KO), and ASC knockout (ASC KO) mice were used in the present study. Then, eNOS/ASC double-knockout (eNOS/ASC DKO) mice were generated by crossing eNOS KO and ASC KO mice. These mice were sacrificed at 17-19 months old. The Masson positive area and the KIM-1 positive area tended to increase in eNOS KO mice, compared with WT mice, but not eNOS/ASC DKO mice. The COX-positive area was significantly reduced in eNOS KO mice, compared with WT and eNOS/ASC DKO mice. To determine whether inflammasomes were activated in infiltrating macrophages, the double staining of IL-18 and F4/80 was performed. IL-18 and F4/80 were found to be co-localised in the tubulointerstitial areas. Inflammasomes play a pivotal role in inflammaging in ageing kidneys. Furthermore, inflammasome activation may accelerate cellular senescence via mitochondrial dysfunction. The importance of endothelial function as a regulatory mechanism suggests that protection of endothelial function may be a potential therapeutic target.

Effect of zinc deficiency on chronic kidney disease progression and effect modification by hypoalbuminemia.

Serum zinc (Zn) levels tend to be low in chronic kidney disease (CKD) patients. This cohort study was conducted to investigate the relationship between zinc deficiency and CKD progression. Patients were classified into two groups based on Zn levels < 60 µg/dl (low-Zn group, n = 160) and ≥ 60 µg/dl (high-Zn group, n = 152). The primary outcome was defined as end-stage kidney disease (ESKD) or death and was examined over a 1-year observation period. Overall, the mean Zn level was 59.6 µg/dl and the median eGFR was 20.3 ml/min/1.73 m2. The incidence of the primary outcome was higher in the low-Zn group (p<0.001). Various Cox proportional hazards models adjusted for baseline characteristics showed higher risks of the primary outcome in the low-Zn group than in the high-Zn group. Competing risks analysis showed that low Zn levels were associated with ESKD but not with death. Moreover, in propensity score-matched analysis, the low-Zn group showed a higher risk of the primary outcome [adjusted hazard ratio 1.81 (95% confidence interval 1.02, 3.24)]. Furthermore, an interaction was observed between Zn and serum albumin levels (interaction p = 0.026). The results of this study indicate that zinc deficiency is a risk factor for CKD progression.

Efficacy of shear wave elastography for evaluating right ventricular myocardial fibrosis in monocrotaline-induced pulmonary hypertension rats.

BACKGROUND: Right ventricular (RV) function is important for outcomes in pulmonary hypertension. Evaluation of RV myocardial characteristics is useful to assess the disease severity. Shear wave elastography (SWE) provides information of shear wave (SW) elasticity, which is related to tissue hardness, and SW dispersion slope, which reflects tissue viscosity. This study aimed to test the hypothesis that SW elasticity is increased and SW dispersion slope is decreased in the right ventricle of monocrotaline (MCT)-induced pulmonary hypertension rats. METHODS: Rats were divided into MCT-induced pulmonary hypertension group (n = 10) and control group (n = 10). SW elasticity and SW dispersion slope were measured on excised hearts. Myocardial fibrosis was evaluated histologically. RESULTS: RV hypertrophy was observed in the MCT group. SW elasticity of right ventricle was higher in the MCT group than in the control group (3.5 ± 0.9 kPa vs. 2.5 ± 0.4 kPa, p < 0.01). SW dispersion slope of right ventricle was lower in the MCT group than in the control group (5.3 ± 1.7 m/s/kHz vs. 7.7 ± 1.5 m/s/kHz, p < 0.01). The fibrosis area of right ventricle was increased in MCT group compared with control group (18 ± 5% vs. 8 ± 3%, p < 0.01), and was positively related to SW elasticity and negatively related to SW dispersion slope. CONCLUSIONS: Higher SW elasticity and lower SW dispersion slope were observed in the fibrotic myocardium of right ventricle in MCT-induced pulmonary hypertension rats. SWE may have the potential to evaluate RV function by assessing myocardial characteristics.

Inhibitory effects of RAGE-aptamer on development of monocrotaline-induced pulmonary arterial hypertension in rats.

BACKGROUND: The receptor for advanced glycation end products (RAGE), a transmembrane receptor belonging to the immunoglobulin superfamily, is overexpressed in pulmonary artery smooth muscle cells (PASMCs) in patients with pulmonary arterial hypertension (PAH) and is implicated in the etiology of PAH. Recently, we reported that RAGE-aptamer, a short and single-stranded DNA directed against RAGE, inhibited an inappropriate increase in cultured PASMCs in PAH. The aim of this study was to determine the efficacy of RAGE-aptamer in monocrotaline-induced PAH in rats. METHODS AND RESULTS: Rats were assigned to either an untreated control group, a group that received continuous subcutaneous administration of RAGE-aptamer immediately after monocrotaline injection, or a group that received control-aptamer immediately after monocrotaline injection. All rats survived 21 days after injection of monocrotaline and control-aptamer or RAGE-aptamer. Injection of monocrotaline with continuous subcutaneous delivery of control-aptamer resulted in higher right ventricular systolic pressure compared with controls. This increase was attenuated by continuous subcutaneous delivery of RAGE-aptamer. The proportion of small pulmonary arteries with full muscularization was greater in the monocrotaline and control-aptamer group than in the control group. Continuous subcutaneous delivery of RAGE-aptamer significantly reduced the percentage of small pulmonary arteries with full muscularization. CONCLUSIONS: Continuous subcutaneous delivery of RAGE-aptamer suppresses development of monocrotaline-induced PAH in rats. Inhibition of RAGE ameliorates muscularization of small pulmonary arteries. Treatment with RAGE-aptamer might be a new therapeutic option for PAH.

Combination therapy with pemafibrate (K-877) and pitavastatin improves vascular endothelial dysfunction in dahl/salt-sensitive rats fed a high-salt and high-fat diet.

BACKGROUND: Statins suppress the progression of atherosclerosis by reducing low-density lipoprotein (LDL) cholesterol levels. Pemafibrate (K-877), a novel selective peroxisome proliferator-activated receptor α modulator, is expected to reduce residual risk factors including high triglycerides (TGs) and low high-density lipoprotein (HDL) cholesterol during statin treatment. However, it is not known if statin therapy with add-on pemafibrate improves the progression of atherosclerosis. The aim of this study was to assess the effect of combination therapy with pitavastatin and pemafibrate on lipid profiles and endothelial dysfunction in hypertension and insulin resistance model rats. METHODS: Seven-week-old male Dahl salt-sensitive (DS) rats were divided into the following five treatment groups (normal diet (ND) plus vehicle, high-salt and high-fat diet (HD) plus vehicle, HD plus pitavastatin (0.3 mg/kg/day), HD plus pemafibrate (K-877) (0.5 mg/kg/day), and HD plus combination of pitavastatin and pemafibrate) and treated for 12 weeks. At 19 weeks, endothelium-dependent relaxation of the thoracic aorta in response to acetylcholine was evaluated. RESULTS: After feeding for 12 weeks, systolic blood pressure and plasma levels of total cholesterol were significantly higher in the HD-vehicle group compared with the ND-vehicle group. Combination therapy with pitavastatin and pemafibrate significantly reduced systolic blood pressure, TG levels, including total, chylomicron (CM), very LDL (VLDL), HDL-TG, and cholesterol levels, including total, CM, VLDL, and LDL-cholesterol, compared with vehicle treatment. Acetylcholine caused concentration-dependent relaxation of thoracic aorta rings that were pre-contracted with phenylephrine in all rats. Relaxation rates in the HD-vehicle group were significantly lower compared with the ND-vehicle group. Relaxation rates in the HD-combination of pitavastatin and pemafibrate group significantly increased compared with the HD-vehicle group, although neither medication alone ameliorated relaxation rates significantly. Western blotting experiments showed increased phosphorylated endothelial nitric oxide synthase protein expression in aortas from rats in the HD-pemafibrate group and the HD-combination group compared with the HD-vehicle group. However, the expression levels did not respond significantly to pitavastatin alone. CONCLUSIONS: Combination therapy with pitavastatin and pemafibrate improved lipid profiles and endothelial dysfunction in hypertension and insulin resistance model rats. Pemafibrate as an add-on strategy to statins may be useful for preventing atherosclerosis progression.

Deficiency of CD44 prevents thoracic aortic dissection in a murine model.

Thoracic aortic dissection (TAD) is a life-threatening vascular disease. We showed that CD44, a widely distributed cell surface adhesion molecule, has an important role in inflammation. In this study, we examined the role of CD44 in the development of TAD. TAD was induced by the continuous infusion of ß-aminopropionitrile (BAPN), a lysyl oxidase inhibitor, and angiotensin II (AngII) for 7 days in wild type (WT) mice and CD44 deficient (CD44-/-) mice. The incidence of TAD in CD44-/- mice was significantly reduced compared with WT mice (44% and 6%, p < 0.01). Next, to evaluate the initial changes, aortic tissues at 24 hours after BAPN/AngII infusion were examined. Neutrophil accumulation into thoracic aortic adventitia in CD44-/- mice was significantly decreased compared with that in WT mice (5.7 ± 0.3% and 1.6 ± 0.4%, p < 0.01). In addition, BAPN/AngII induced interleukin-6, interleukin-1ß, matrix metalloproteinase-2 and matrix metalloproteinase-9 in WT mice, all of which were significantly reduced in CD44-/- mice (all p < 0.01). In vitro transmigration of neutrophils from CD44-/- mice through an endothelial monolayer was significantly decreased by 18% compared with WT mice (p < 0.01). Our findings indicate that CD44 has a critical role in TAD development in association with neutrophil infiltration into adventitia.

Klotho is a novel therapeutic target in peritoneal fibrosis via Wnt signaling inhibition.

BACKGROUND: Long-term exposure to bioincompatible peritoneal dialysate causes the loss of mesothelial cells and accumulation of matrix proteins, leading to an increase in the thickness of the submesothelial layer, thereby limiting the long-term effectiveness of peritoneal dialysis (PD). However, the detailed molecular mechanisms underlying the process of peritoneal fibrosis have not been clearly elucidated. Wnt/ß-catenin signaling pathway activation has been suggested to play a pivotal role in the development of organ fibrosis. Moreover, Klotho protein can regulate Wnt/ß-catenin signaling. We examined the role of Klotho protein in reducing peritoneal fibrosis by inhibiting Wnt/ß-catenin signaling. METHODS: The ß-catenin-activated transgenic (BAT) driving expression of nuclear ß-galactosidase reporter transgenic (BAT-LacZ) mice, the alpha-Klotho gene under control of human elongation factor 1 alpha promoter [Klotho transgenic (KLTG) and C57BL/6 background] and C57BL/6 mice [wild-type (WT)] were used. The mice received daily intraperitoneal (i.p.) injections of 4.25% glucose with lactate (PD solution) or saline as a control for 4 weeks. Other mice received daily i.p. injections of the same volume of saline (normal control). RESULTS: After exposure to PD, Wnt signal activation was observed on the peritoneal mesothelial cells in WT-PD mice. The peritoneal fibrosis was also accelerated in WT-PD mice. The protein expression of ß-catenin and Wnt-inducible genes were also remarkably increased in WT-PD mice. On the other hand, KLTG-PD mice attenuated activation of Wnt/ß-catenin signaling after exposure to PD and ameliorated the progression of peritoneal fibrosis. CONCLUSIONS: Overexpression of Klotho protein protects the peritoneal membrane through attenuation of the Wnt/ß-catenin signaling pathway. The availability of recombinant Klotho protein would provide a novel potential therapeutic target in peritoneal fibrosis.

Age control of the first appearance datum for Javanese Homo erectus in the Sangiran area.

The chronology of the World Heritage Site of Sangiran in Indonesia is crucial for the understanding of human dispersals and settlement in Asia in the Early Pleistocene (before 780,000 years ago). It has been controversial, however, especially regarding the timing of the earliest hominin migration into the Sangiran region. We use a method of combining fission-track and uranium-lead dating and present key ages to calibrate the lower (older) Sangiran hominin-bearing horizons. We conclude that the first appearance datum for the Sangiran hominins is most likely ~1.3 million years ago and less than 1.5 million years ago, which is markedly later than the dates that have been widely accepted for the past two decades.

Inhibitory Effects of Tofogliflozin on Cardiac Hypertrophy in Dahl Salt-Sensitive and Salt-Resistant Rats Fed a High-Fat Diet.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are drugs for diabetes and might prevent heart failure. In this study, we investigated the effects of tofogliflozin, an SGLT2 inhibitor, on cardiac hypertrophy and metabolism in hypertensive rats fed a high-fat diet. Dahl salt-sensitive (DS) rats, hypertensive model rats, and Dahl salt-resistant (DR) rats, non-hypertensive model rats, were fed a high-salt and high-fat diet containing tofogliflozin (0.005%) for 9 weeks to examine the effects of this drug on cardiac hypertrophy and metabolism. Tofogliflozin tended to suppress a rise of the systolic blood pressure, relative to the control, throughout the treatment period in both DR and DS rats, and significantly suppress a rise of the systolic blood pressure, relative to the control, at the 9th week in DS rats. Tofogliflozin reduced cardiac hypertrophy (heart weight/body weight) not only in DS rats but also in DR rats. Histological analysis showed that tofogliflozin significantly decreased cardiomyocyte hypertrophy and perivascular fibrosis in both DS and DR rats. Tofogliflozin significantly decreased the expression levels of genes related to cardiac hypertrophy (encoding for natriuretic peptides A and B and interleukin-6), and to cardiac fibrosis (encoding for transforming growth factor-ß1 and collagen type IV), in DS rats. Recent studies have shown that hypertrophied and failing hearts shift to oxidizing ketone bodies as a significant fuel source. We also performed metabolome analysis for ventricular myocardial tissue. Tofogliflozin reduced 3-hydroxybutyrate, a ketone body, and significantly decreased the expression levels of ß-hydroxybutyrate dehydrogenase 1 and 3-oxoacid CoA-transferase, which are related to ketone oxidization. In conclusion, tofogliflozin ameliorated cardiac hypertrophy and fibrosis along with reduction of ketone usage in myocardial tissue.