Dimethyl Fumarate Ameliorated Cardiorenal Anemia Syndrome and Improved Overall Survival in Dahl/Salt-Sensitive Rats.

Cardiovascular disease, chronic kidney disease, and anemia are known to adversely affect each other. Inflammation is commonly involved in these diseases. Cardiorenal anemia syndrome (CRAS) is the name given to this mutually harmful condition. Dimethyl fumarate (DMF) is a Food and Drug Administration-approved antioxidant and anti-inflammatory agent. The purpose of this study was to investigate the effects of DMF on Dahl/salt-sensitive (DS) rats as a CRAS model. Six-week-old DS rats were divided into three groups: the control group, the high-salt (HS) group, and the HS+DMF group. The HS and HS+DMF groups were fed a high-salt diet (8% NaCl) from 6 weeks of age. In the HS+DMF group, DMF (90 mg/kg per day) was orally administered from 6 to 15 weeks of age. Systolic blood pressure was measured every 2 weeks. The heart and renal injuries were assessed with histopathological analysis. The heart and renal expression of mRNAs was assessed by reverse-transcription polymerase chain reaction. DMF significantly improved overall survival, which was shortened by HS in DS rats. Systolic blood pressure increased in the HS group compared with the control group, and DMF tended to suppress this change. DMF ameliorated the cardiac and renal abnormalities confirmed in the HS group by histopathological analysis. Furthermore, the changes in mRNA expressions associated with disease exacerbation in the HS group were suppressed by DMF. DMF also improved anemia. This study suggests that DMF improves overall survival in DS rats through organ-protective effects and is effective against cardiorenal anemia syndrome. SIGNIFICANCE STATEMENT: Dimethyl fumarate was found to improve overall survival in Dahl/salt-sensitive rats, associated with its ability to ameliorate anemia and induce cardioprotective and renoprotective effects through anti-inflammatory and antifibrotic effects.

Juzentaihoto improves adenine-induced chronic renal failure in BALB/c mice via suppression of renal fibrosis and inflammation.

Renal inflammation and fibrosis are observed in underlying diseases associated with the pathological progression of chronic kidney disease (CKD). The inhibition of renal inflammation and fibrosis is one method to suppress the progression of CKD. Juzentaihoto (TJ-48), a Kampo medicine, effectively relieves chronic wasting diseases and fatigue and has been reported to decrease inflammation. In this study, we investigated whether TJ-48 has a renal protective effect and its underlying mechanism in mice with adenine-induced CKD. BALB/c mice were divided into four groups for examination: (1) control, (2) dietary restriction, (3) adenine, and (4) adenine + TJ-48. Biochemical and histological analyses, gene expression analysis, and complete blood counts were performed. TJ-48 treatment decreased tubular damage and fibrosis. TJ-48 also decreased creatinine levels exacerbated by adenine, suppressed the mRNA expression of tumor necrosis factor-α, chemokine ligand 2, transforming growth factor-ß, and kidney injury molecule-1, and decreased the neutrophil/lymphocyte ratio increased by adenine. TJ-48 exerts a renoprotective effect possibly via the suppression of fibrosis and inflammation.

Low Quality of Warfarin Therapy is Associated With Female Gender but Not With Polypharmacy in Patients With Atrial Fibrillation.

Background: We examined the impact of polypharmacy on the quality of the anticoagulation therapy in patients with atrial fibrillation. We also examined the factors that affect the stability of warfarin therapy. Methods and Results: This retrospective study was conducted using data from 157 consecutive outpatients with atrial fibrillation in a single tertiary referral hospital. Patients who were prescribed warfarin continuously and for whom PT-INR was examined at least three times in a year were included in this study. We examined the quality of warfarin therapy using time in the therapeutic INR range (TTR), percentage of PT-INR determinations in range (PINRR), and the coefficient variation (CV) of PT-INR. We found that the number of prescribed medicines was significantly associated with high BMI and low eGFR, but not with TTR, PINRR, and the coefficient variation of PT-INR in patients with atrial fibrillation. We also found that female gender was independently associated with low PINRR in this study population. Conclusion: Polypharmacy did not deteriorate the quality of warfarin therapy in patients with atrial fibrillation treated in the tertiary referral hospital. Female gender was an independent predictor of the low quality of warfarin therapy.

Reduced lifespan of erythrocytes in Dahl/Salt sensitive rats is the cause of the renal proximal tubule damage.

We studied the mechanisms of anemia and the influence of anemia on renal pathology in Dahl/Salt Sensitive (Dahl/SS) rat, a model of cardio-renal-anemia syndrome. Erythrocyte lifespan was shortened and associated with decreased hemoglobin level in the Dahl/SS rats given high-salt diet. Serum haptoglobin decreased, reticulocytes increased, and erythropoiesis in the bone marrow and extramedullary hematopoiesis in the spleen was markedly stimulated by increased serum erythropoietin in them. As a mechanism of hemolysis, we investigated the incidence of eryptosis, suicidal death of erythrocytes. Eryptosis was increased, and red blood cell-derived microparticles, small particle which are generated in hemolytic disease, were also increased in Dahl/SS rats fed with high-salt diet. Deposition of hemosiderin and mitochondrial morphologic abnormality, a sign of ferroptosis, in proximal renal tubules was associated with intravascular hemolysis. Treatment with deferasirox, an oral iron chelator, reduced the renal proximal tubular injury and the glomerular sclerosis in Dahl/SS rats fed with high-salt diet. In conclusion, reduced half-life of erythrocytes induced by hemolysis is the major cause of anemia in Dahl/SS rat. Iron accumulation induced by hemolysis causes renal proximal tubule injury and accelerates renal damage in this model.

Polypharmacy Is Associated With Accelerated Deterioration of Renal Function in Cardiovascular Outpatients.

BACKGROUND: Polypharmacy is associated with poor prognosis of patients with various diseases. However, it has not been precisely addressed how polypharmacy affects the clinical characteristics of the cardiovascular outpatients. The aim of this study is to search for the clinical characteristics related to the number of prescribed drugs in the cardiovascular outpatients. Also, we examine whether the number of the prescribed drugs affects the worsening of renal function. METHODS: This retrospective study was conducted using the data of 259 continuous cardiovascular outpatients who were examined complete blood count (CBC) and serum creatinine. RESULTS: In the univariate analysis, the number of prescribed drugs were associated with the number of cardiovascular diseases or their risk factors, age, white blood cells, platelet, body mass index, anemia, and chronic kidney disease stage 3b or higher. In the multivariable analysis, independent variables that significantly correlated with the number of prescribed drugs were the number of cardiovascular diseases or their risk factors, anemia, and chronic kidney disease stage 3b or higher. Among 259 patients, 208 patients received follow-up examination of serum creatinine. The number of prescribed drugs was the only factor that was associated with accelerated deterioration of renal function. CONCLUSIONS: Polypharmacy is associated not only with poor renal function but with accelerated deterioration of renal function. Polypharmacy may be causally related with renal dysfunction.

Neutrophil/lymphocyte ratio elevation in renal dysfunction is caused by distortion of leukocyte hematopoiesis in bone marrow.

OBJECTIVE: We investigate the mechanism of neutrophil/lymphocyte ratio (NLR) elevation, a useful prognostic marker in patients with cardiovascular diseases (CVDs). METHODS: In this clinical study, we retrospectively searched for factors associated with NLR elevation in cardiovascular outpatients. In animal experiments using mice with adenine-induced nephropathy, we further examined the hematopoietic process in bone marrow and explored the mechanism of NLR elevation. RESULT: In patients with CVDs or their risk factors, multiple regression analysis revealed that decrease in estimated glemerular filtration rate and increase in white blood cell count were significantly associated with increase in NLR. In mice with adenine-induced nephropathy, NLR and serum indoxyl sulfate (IS) levels were increased. Fluorescence-activated cell sorting revealed the increase in the number of myeloid progenitors and decrease in the number of common lymphoid progenitors, suggesting biased granulocyte side in the hematopoietic process in bone marrow. Treatment with oral charcoal adsorbent AST-120 decreased serum concentration of IS and normalized NLR and bone marrow abnormalities in mice with adenine-induced nephropathy. CONCLUSION: Renal function was a strong determinant of NLR in cardiovascular outpatients. NLR elevation due to renal impairment is caused by distortion of the hematopoietic process in bone marrow. IS plays a significant role in these processes.

Exendin-4 Prevents Vascular Smooth Muscle Cell Proliferation and Migration by Angiotensin II via the Inhibition of ERK1/2 and JNK Signaling Pathways.

Angiotensin II (Ang II) is a main pathophysiological culprit peptide for hypertension and atherosclerosis by causing vascular smooth muscle cell (VSMC) proliferation and migration. Exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist, is currently used for the treatment of type-2 diabetes, and is believed to have beneficial effects for cardiovascular diseases. However, the vascular protective mechanisms of GLP-1 receptor agonists remain largely unexplained. In the present study, we examined the effect of exendin-4 on Ang II-induced proliferation and migration of cultured rat aortic smooth muscle cells (RASMC). The major findings of the present study are as follows: (1) Ang II caused a phenotypic switch of RASMC from contractile type to synthetic proliferative type cells; (2) Ang II caused concentration-dependent RASMC proliferation, which was significantly inhibited by the pretreatment with exendin-4; (3) Ang II caused concentration-dependent RASMC migration, which was effectively inhibited by the pretreatment with exendin-4; (4) exendin-4 inhibited Ang II-induced phosphorylation of ERK1/2 and JNK in a pre-incubation time-dependent manner; and (5) U0126 (an ERK1/2 kinase inhibitor) and SP600125 (a JNK inhibitor) also inhibited both RASMC proliferation and migration induced by Ang II stimulation. These results suggest that exendin-4 prevented Ang II-induced VSMC proliferation and migration through the inhibition of ERK1/2 and JNK phosphorylation caused by Ang II stimulation. This indicates that GLP-1 receptor agonists should be considered for use in the treatment of cardiovascular diseases in addition to their current use in the treatment of diabetes mellitus.

Olmesartan inhibits cultured rat aortic smooth muscle cell death induced by cyclic mechanical stretch through the inhibition of the c-Jun N-terminal kinase and p38 signaling pathways.

Acute aortic dissection (AAD) is a life-threating disease; however, there is almost no effective pharmacotherapy for it. An increase in c-Jun N-terminal kinase (JNK) phosphorylation and smooth muscle cell (SMC) apoptosis is observed tissues in patients with AAD. Therefore, we hypothesized that an acute rise in blood pressure leads to SMC death through phosphorylation of JNK or p38, which may cause AAD. We investigated the influence of cyclic mechanical stretch, which mimics an acute increase in blood pressure, on cultured rat aortic SMCs (RASMCs) and examined the changes in JNK and p38 phosphorylation. Further, we investigated the effect of olmesartan, an angiotensin II receptor blocker, on stretch-induced RASMC death. We found that mechanical stretch-induced RASMC death in a time-dependent manner, which correlated with the phosphorylation of JNK and p38. Olmesartan inhibited RASMC death and the phosphorylation of JNK and p38. JNK and p38 inhibitors reversed stretch-induced RASMC death. These results suggest that acute mechanical stretch causes JNK and p38 phosphorylation, which may result in SMC death leading to aortic dissection. Olmesartan may be used for pharmacotherapy to prevent aortic dissection, independent of its blood pressure-lowering effect, through its inhibition of JNK and p38 phosphorylation.

Azelnidipine inhibits cultured rat aortic smooth muscle cell death induced by cyclic mechanical stretch.

Acute aortic dissection is the most common life-threatening vascular disease, with sudden onset of severe pain and a high fatality rate. Clarifying the detailed mechanism for aortic dissection is of great significance for establishing effective pharmacotherapy for this high mortality disease. In the present study, we evaluated the influence of biomechanical stretch, which mimics an acute rise in blood pressure using an experimental apparatus of stretching loads in vitro, on rat aortic smooth muscle cell (RASMC) death. Then, we examined the effects of azelnidipine and mitogen-activated protein kinase inhibitors on mechanical stretch-induced RASMC death. The major findings of the present study are as follows: (1) cyclic mechanical stretch on RASMC caused cell death in a time-dependent manner up to 4 h; (2) cyclic mechanical stretch on RASMC induced c-Jun N-terminal kinase (JNK) and p38 activation with peaks at 10 min; (3) azelnidipine inhibited RASMC death in a concentration-dependent manner as well as inhibited JNK and p38 activation by mechanical stretch; and (4) SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor) protected against stretch-induced RASMC death; (5) Antioxidants, diphenylene iodonium and tempol failed to inhibit stretch-induced RASMC death. On the basis of the above findings, we propose a possible mechanism where an acute rise in blood pressure increases biomechanical stress on the arterial walls, which induces RASMC death, and thus, may lead to aortic dissection. Azelnidipine may be used as a pharmacotherapeutic agent for prevention of aortic dissection independent of its blood pressure lowering effect.

Intermittent hypoxia induces the proliferation of rat vascular smooth muscle cell with the increases in epidermal growth factor family and erbB2 receptor.

Obstructive sleep apnea is characterized by intermittent hypoxia (IH), and associated with cardiovascular diseases, such as stroke and heart failure. These cardiovascular diseases have a relation to atherosclerosis marked by the proliferation of vascular smooth muscle cells (VSMCs). In this study, we investigated the influence of IH on cultured rat aortic smooth muscle cell (RASMC). The proliferation of RASMC was significantly increased by IH without changing the level of apoptosis. In order to see what induces RASMC proliferation, we investigated the influence of normoxia (N)-, IH- and sustained hypoxia (SH)-treated cell conditioned media on RASMC proliferation. IH-treated cell conditioned medium significantly increased RASMC proliferation compared with N-treated cell conditioned medium, but SH-treated cell conditioned medium did not. We next investigated the epidermal growth factor (EGF) family as autocrine growth factors. Among the EGF family, we found significant increases in mRNAs for epiregulin (ER), amphiregulin (AR) and neuregulin-1 (NRG1) in IH-treated cells and mature ER in IH-treated cell conditioned medium. We next investigated the changes in erbB family receptors that are receptors for ER, AR and NRG1, and found that erbB2 receptor mRNA and protein expressions were increased by IH, but not by SH. Phosphorylation of erbB2 receptor at Tyr-1248 that mediates intracellular signaling for several physiological effects including cell proliferation was increased by IH, but not by SH. In addition, inhibitor for erbB2 receptor suppressed IH-induced cell proliferation. These results provide the first demonstration that IH induces VSMC proliferation, and suggest that EGF family, such as ER, AR and NRG1, and erbB2 receptor could be involved in the IH-induced VSMC proliferation.

Role of big mitogen-activated protein kinase 1 (BMK1) / extracellular signal-regulated kinase 5 (ERK5) in the pathogenesis and progression of atherosclerosis.

Big mitogen-activated protein kinase 1 (BMK1), also known as extracellular signal-regulated kinase 5 (ERK5), is a newly identified member of the mitogen-activated protein (MAP) kinase family. BMK1 has been reported to be sensitive to various neuro-humoral factors and oxidative stress in various cells. In this review, we focused on the role of BMK1 in atherosclerosis in a cultured rat aortic smooth muscle cell model. Treatment with platelet-derived growth factor caused vascular smooth muscle cell (VSMC) migration in a BMK1 activation-dependent manner. H(2)O(2) caused BMK1 activation and VSMC death, including apoptosis of VSMCs. An inhibitory function for BMK1 against cell death from oxidative stress was discovered using siRNA techniques to downregulate the expression of BMK1. These findings suggest a role for BMK1 in the pathogenesis and/or progression of atherosclerosis.