Bilateral or Unilateral Aldosterone Hypersecretion and Responsiveness to Therapy Are Associated with Differences in Calcium/Phosphate Homeostasis in Patients with Primary Aldosteronism.

Introduction Primary aldosteronism is characterized by the autonomous excretion of aldosterone, which may induce bone mineral disorders. Methods A total of 96 patients with primary aldosteronism were analyzed to identify differences in the regulation of serum calcium/phosphate balance between patients with unilateral and bilateral aldosterone hypersecretion and to determine whether or not adrenalectomy or mineralocorticoid receptor blockers affected such differences. Results Serum phosphate concentrations were significantly lower in patients with unilateral aldosterone hypersecretion than in patients with bilateral aldosterone hypersecretion (2.96±0.45 vs. 3.36±0.55 mg/dL, p<0.05), and recovered after adrenalectomy (2.96±0.45 vs. 3.49±0.32 mg/dL, p<0.01). In patients with bilateral aldosterone hypersecretion, the baseline serum phosphate levels were significantly lower in responders to mineralocorticoid receptor blocker treatment, defined as post-treatment plasma renin activity ≥1 ng/mL/h, than in non-responders. In responders, these levels tended to recover after treatment. A weak negative correlation between the plasma aldosterone concentration (PAC) and serum phosphate was observed, but there were no associations between the PAC and serum calcium concentration or between the aldosterone renin ratio and serum calcium and phosphate concentrations. Conclusion The effects on calcium/phosphate homeostasis may differ according to the primary aldosteronism subtype.

Antihypertensive Drugs and Cancer Risk.

Hypertension is the most prevalent comorbidity in cancer patients. Consequently, many cancer patients are prescribed antihypertensive drugs before cancer diagnosis or during cancer treatment. However, whether antihypertensive drugs affect the incidence, treatment efficacy, or prognosis of cancer remains unanswered. For instance, renin-angiotensin and ß-adrenergic signaling may be involved not only in blood pressure elevation but also in cell proliferation, angiogenesis, and tissue invasion. Therefore, the inhibition of these pathways may have beneficial effects on cancer prevention or treatment. In this article, we reviewed several studies regarding antihypertensive drugs and cancer. In particular, we focused on the results of clinical trials to evaluate whether the use of antihypertensive drugs affects future cancer risk and prognosis. Unfortunately, the results are somewhat inconsistent, and evidence demonstrating the effect of antihypertensive drugs remains limited. We indicate that the heterogeneity in the study designs makes it difficult to clarify the causal relationship between antihypertensive drugs and cancer. We also propose that additional experimental studies, including research with induced pluripotent cells derived from cancer patients, single-cell analyses of cancer cell clusters, and clinical studies using artificial intelligence electronic health record systems, might be helpful to reveal the precise association between antihypertensive drugs and cancer risk.

New Concept of Onco-Hypertension and Future Perspectives.

Owing to aging populations, the prevalence of hypertension and associated cardiovascular events has been increasing worldwide. The morbidity and mortality due to cancer have also been increasing with aging populations. Several small-molecule inhibitors have been used in cancer therapy, which have a positive impact on the prognosis and survival of patients with cancer. Consequently, the number of cancer survivors with hypertension has been rapidly increasing. Anticancer therapy, including vascular endothelial growth factor inhibitors, increases blood pressure. However, both clinical and laboratory evidence are lacking regarding optimal blood pressure control in patients with hypertension with cancer. Here, we propose the concept of onco-hypertension, which is an evolving subspecialty focused on the complex pathophysiology of hypertension and cancer. In this review, we highlight blood pressure changes in cancer, hypertension induced by anticancer therapy, and optimal blood pressure management in patients with hypertension with cancer. In addition, we discuss needed studies to further establish this new onco-hypertension concept.

Evaluation of various confirmatory tests for the diagnosis of aldosterone-producing adenoma.

INTRODUCTION: Adrenal venous sampling is useful for discriminating unilateral and bilateral hypersecretion in patients with primary aldosteronism, but it is relatively invasive. To determine the site of hypersecretion more non-invasively, we evaluated predictors of unilateral hypersecretion. MATERIALS AND METHODS: We evaluated the baseline characteristics and the results of confirmatory tests of 123 patients with primary aldosteronism who underwent adrenal venous sampling. RESULTS: Unilateral hypersecretion was identified in 22.0%. The plasma aldosterone concentration and aldosterone-renin ratio were significantly higher and serum potassium concentration and plasma renin activity were significantly lower in patients with unilateral hypersecretion. Plasma aldosterone concentrations after captopril challenge test, saline infusion test and rapid adrenocorticotropic hormone stimulation test were significantly higher among patients with unilateral hypersecretion. The plasma aldosterone concentration reduction ratio in saline infusion test and plasma aldosterone concentration elevation ratio during rapid adrenocorticotropic hormone stimulation test were significantly higher in patients with unilateral hypersecretion. However, areas under the curve for these parameters were not superior to the values after confirmatory tests. CONCLUSIONS: The plasma aldosterone concentration values after captopril challenge test, saline infusion test and rapid adrenocorticotropic hormone stimulation test were useful for identifying patients with unilateral hypersecretion. However, value changes or ratios during confirmatory tests are less useful for this aim.

Forced expression of vascular endothelial growth factor-A in podocytes decreases mesangial cell numbers and attenuates endothelial cell differentiation in the mouse glomerulus.

BACKGROUND: Glomerular podocyte-derived vascular endothelial growth factor (VEGF) is indispensable for the migration and proliferation of glomerular endothelial cells. In contrast, podocyte-specific Vegf overexpression leads to the collapse of glomerular tufts; however, the mechanisms underlying this outcome have not yet been reported. METHODS: To further clarify the effects of elevated levels of Vegf expression on glomerular cells, we established a dual transgenic mouse line in which Vegf was exclusively and inducibly expressed in podocytes under the control of the "Tet-on system" (Podocin-rtTA/TetO-Vegf164 mice). RESULTS: Macroscopic and microscopic examination of Podocin-rtTA/TetO-Vegf164 animals following Vegf induction identified the presence of prominent red bloody spots. In addition, the endothelial cell number was increased along with enlargement of the subendothelial spaces. We also observed impaired endothelial fenestrations and aberrant plasmalemmal vesicle-associated protein-1 (PV-1) expression. In contrast, the mesangial cell number markedly decreased, resulting in a glomerular tuft intussusceptive splitting defect. Furthermore, whereas platelet-derived growth factor-B (PDGF-B) expression in the glomerular cells of Podocin-rtTA/TetO-Vegf164 mice was not decreased, phospho-PDGF receptor immunoreactivity in the mesangial cells was significantly decreased when compared to wild-type animals. CONCLUSION: Taken together, the results of this study indicated that the upregulation of podocyte VEGF decreased the number of mesangial cells, likely owing to inhibition of PDGF-B-mediated signaling.

Plasma cell-rich rejection accompanied by acute antibody-mediated rejection in a patient with ABO-incompatible kidney transplantation.

We report a case of plasma cell-rich rejection accompanied by acute antibody-mediated rejection in a patient with ABO-incompatible kidney transplantation. A 33-year-old man was admitted for an episode biopsy; he had a serum creatinine (S-Cr) level of 5.7 mg/dL 1 year following primary kidney transplantation. Histological features included two distinct entities: (1) a focal, aggressive tubulointerstitial inflammatory cell (predominantly plasma cells) infiltration with moderate tubulitis; and (2) inflammatory cell infiltration (including neutrophils) in peritubular capillaries. Substantial laboratory examination showed that the patient had donor-specific antibodies for DQ4 and DQ6. Considering both the histological and laboratory findings, we diagnosed him with plasma cell-rich rejection accompanied by acute antibody-mediated rejection. We started 3 days of consecutive steroid pulse therapy three times every 2 weeks for the former and plasma exchange with intravenous immunoglobulin (IVIG) for the latter histological feature. One month after treatment, a second allograft biopsy showed excellent responses to treatment for plasma cell-rich rejection, but moderate, acute antibody-mediated rejection remained. Therefore, we added plasma exchange with IVIG again. After treatment, allograft function was stable, with an S-Cr level of 2.8 mg/dL. This case report demonstrates the difficulty of the diagnosis of, and treatment for, plasma cell-rich rejection accompanied by acute antibody-mediated rejection in a patient with ABO-incompatible kidney transplantation. We also include a review of the related literature.

[Study on the predictors for superimposed preeclampsia in patients with IgA nephropathy].

OBJECTIVE: Pregnancy in chronic kidney disease (CKD) patients is often associated with hypertension and/or the worsening of renal function and neonatal death. The present study explored the clinical characteristics of predictive factors for hypertension in biopsy-proven IgA nephropathy patients with superimposed preeclampsia (SPE). PATIENTS AND METHODS: The subjects were 34 Japanese women with IgA nephropathy whose renal specimen for histological tests was obtained before pregnancy. We retrospectively investigated the relevant clinical factors to explain a rise in blood pressure (BP). The histological findings were evaluated with respect to the quantitative measurements of both global glomerulosclerosis and interstitial damage. RESULTS: Renal biopsies before pregnancies showed that the global glomerular sclerosing index and interstitial damage in the SPE group were significantly higher than in the normal group. The prevalence of SPE was 38.2 % (normal pregnancy 21, SPE 13 cases). The neonatal death rate was 3.0 % (1/34)overall. Just before conception, systolic blood pressure (SBP), serum creatinine (Cr)and blood urea nitrogen (BUN) concentration in the SPE were significantly higher than in normal pregnancies. In contrast, CCr and eGFR were lower in the SPE group than in the normal group. At delivery, serum Cr, BUN and uric acid (UA) concentration in the SPE group were significantly higher than in the normal group. In contrast, CCr and eGFR were lower in the SPE than in the normal group. At delivery, correlation analysis revealed a significant correlation between SBP or diastolic BP (DBP) and the histological severity, between SBP or DBP and daily protein excretion, and between SBP or DBP and serum Cr concentration. With respect to the birth weight of newborns, there was a significant negative correlation between the birth weight and the global glomerular sclerosing rate, and between the birth weight and serum Cr concentration or BUN. A stepwise multiple regression analysis showed that predictive factors for a rise in SBP during pregnancy were the degree of interstitial damage and daily urinary protein excretion. These results suggest that renal function, the magnitude of urinary protein excretion, serum Cr, BUN, UA concentrations, and the severity of histological abnormalities are all associated with SPE occurrence. The predictors of a rise in BP were interstitial damage and urinary protein excretion at pregnancy. In addition, Receiver Operating Characteristic (ROC) analysis showed that both glomerular sclerosis and interstitial damage could be potential predictors for SPE. CONCLUSION: Histological severity in renal biopsy, urinary protein excretion and renal function are associated with SPE in patients with IgA nephropathy. Among these associations, the histological findings and urinary protein excretion may serve as useful predictors for a rise in BP.

Successful effect of triple blockade of renin-angiotensin-aldosterone system on massive proteinuria in a patient with chronic kidney disease.

A patient with chronic kidney disease (CKD) due to membranous nephropathy with daily urinary protein excretion exceeding 5 g did not respond well to dual therapy with an angiotensin converting enzyme inhibitor (ACE-I) and angiotensin II receptor blocker (ARB). Addition of the mineralocorticoid receptor blocker (MRB), spironolactone, led to moderate reduction in daily urinary protein excretion. However, spironolactone had to be inevitably discontinued due to gynecomastia. Replacement of spironolactone with the selective MRB, eplerenone, added to the preceding treatment with ACE-I and ARB, resulted in remarkable reduction of daily urinary protein excretion to less than 0.2 g. This case suggests that triple blockade of renin-angiotensin-aldosterone (RAA) system with ACE-I, ARB, and MRB could be useful for CKD patients with massive proteinuria.

Dimethylarginine dimethylaminohydrolase 2 increases vascular endothelial growth factor expression through Sp1 transcription factor in endothelial cells.

OBJECTIVE: Dimethylarginie dimethylaminohydrolase (DDAH) is a degrading enzyme for asymmetrical dimethylarginine, an endogenous NO synthase inhibitor. The molecular mechanism for DDAH-induced vascular endothelial growth factor (VEGF) expression was examined. METHODS AND RESULTS: Although the transfection of expression vectors for 2 isoforms of DDAH, DDAH1, or DDAH2 increased DDAH activity in bovine aortic endothelial cells and human umbilical vein endothelial cells, expression and secretion of VEGF were increased only in DDAH2-transfected cells. Knocking down the DDAH2 gene reduced VEGF production, and DDAH2 overexpression enhanced both proliferation and migration of endothelial cells. The VEGF promoter activity was increased by DDAH2 transfection, which was not blocked by an NO synthase (NOS) inhibitor but required the Sp1 sites. DDAH2 overexpression increased nuclear protein levels bound to Sp1 oligonucleotides in endothelial cells. Sp1 small interfering RNA blocked DDAH2-induced upregulation of VEGF. DDAH2 transfection increased nuclear and threonine-phosphorylation levels of Sp1 in a protein kinase A (PKA)-dependent manner. Protein-protein interaction between DDAH2 and PKA was enhanced in DDAH2-transfected cells. CONCLUSIONS: DDAH2 upregulated the expression of VEGF through Sp1-dependent and NO/NOS system-independent promoter activation. DDAH2-increased Sp1 DNA binding activity was PKA dependent. These mechanisms may provide a novel therapeutic strategy for VEGF-related vasculopathies such as atherosclerosis.

Rho-kinase as a molecular target for insulin resistance and hypertension.

Rho-kinase plays an important role in hypertension and is reported to interfere with insulin signaling through serine phosphorylation of insulin receptor substrate-1 (IRS-1) in cultured vascular smooth muscle cells. We therefore examined the role of Rho-kinase in the development of insulin resistance in Zucker obese rats. In skeletal muscles and aortic tissues of Zucker obese rats, activation of RhoA/Rho-kinase was observed. Long-term Rho-kinase inhibition by 4 wk treatment with fasudil (a Rho-kinase inhibitor) not only reduced blood pressure but corrected glucose and lipid metabolism, with improvement in serine phosphorylation of IRS-1 and insulin signaling in skeletal muscles. Direct visualization of skeletal muscle arterioles with an intravital CCD videomicroscope demonstrated that both acetylcholine- and sodium nitroprusside-induced vasodilations were blunted, which were restored by the fasudil treatment. Furthermore, both fasudil and Y-27632 prevented the serine phosphorylation of IRS-1 induced by insulin and/or tumor necrosis factor-alpha in skeletal muscle cells. Collectively, Rho-kinase is responsible for the impairment of insulin signaling and may constitute a critical mediator linking between metabolic and hemodynamic abnormalities in insulin resistance.

Divergent action of calcium channel blockers on ATP-binding cassette protein expression.

Calcium channel blockers (CCBs) are widely used in clinical practice, and have been reported to be effective in preventing the progression of atherosclerosis. We examined whether various types of calcium channel blockers affected the expression of ATP binding cassette transporter A1 (ABCA1), a factor contributing to anti-atherogenesis. Undifferentiated monocytic cell line, THP-1 cells were maintained in RPMI 1640 medium and treated with different kinds of calcium channel blockers. Among the calcium channel blockers tested, aranidipine and efonidipine increased ABCA1 protein expression without an increase in ABCA1 mRNA expression, whereas other calcium channel blockers (eg, nifedipine, amlodipine, and nicardipine) or T-type calcium channel blockers (eg, mibefradil and nickel chloride) failed to upregulate ABCA1 expression. H89, a protein kinase A inhibitor inhibited the aranidipine-induced ABCA1 protein expression, whereas genistein (a tyrosine kinase inhibitor), or AG490 (a JAK-2 inhibitor) had no effects. Neither of these inhibitors suppressed the efonidipine-induced ABCA1 protein expression. Intracellular cAMP levels were elevated only by aranidipine, but not by efonidipine. In conclusion, aranidipine and efonidipine have the ability to induce ABCA1 protein by distinct mechanisms; protein kinase A is involved in the aranidipine-induced ABCA1 upregulation. This non-class effect of calcium channel blockers may potentially offer beneficial action in the treatment of hypertensive subjects with atherosclerosis.

Role of Rho-kinase and p27 in angiotensin II-induced vascular injury.

Angiotensin II enhances the development of atherosclerotic lesion in which cellular proliferation and/or migration are critical steps. Although cyclin-dependent kinase inhibitor, p27, and Rho/Rho-kinase pathway have recently been implicated as factors regulating these events cooperatively, their role in vivo has not been fully elucidated. We evaluated the contribution of p27 and Rho-kinase to angiotensin II-induced vascular injury using p27-deficient mice. Two-week angiotensin II (1500 ng/kg per minute SC) infusion elicited similar degrees of elevation in systolic blood pressure in wild-type mice (159+/-5 mm Hg) and p27-deficient mice (157+/-5 mm Hg; P>0.05). Angiotensin II infusion to wild-type mice resulted in increases in the medial thickness of aorta, proliferating cell number, and monocyte/macrophage infiltration within the vasculature. In p27-deficient mice, however, these changes were more prominent than those in wild-type mice. Treatment of wild-type mice with fasudil, a selective Rho-kinase inhibitor, did not alter blood pressure but significantly upregulated p27 expression, decreased medial thickness of aorta, reduced proliferating cell number, and prevented monocyte/macrophage infiltration. These protective effects of fasudil were attenuated in p27-deficient mice. In conclusion, p27 constitutes an important modulator of angiotensin II-induced monocyte/macrophage infiltration and vascular remodeling, which is mediated in part by Rho-kinase stimulation. Inhibition of Rho-kinase activity improves angiotensin II-induced vascular injury through p27-dependent and p27-independent mechanisms.