Association between circulatory complement activation and hypertensive renal damage: a case-control study.

OBJECTIVE: The aim of this study was to investigate the potential importance of complement system activation, with particular emphasis on the complement alternative pathway (AP), in the pathogenesis of hypertensive renal damage. METHODS: Serum complement C3, complement Factor H (CFH) and AP activation were assessed in 66 participants with established essential hypertension with renal damage (RD). Fifty-nine patients with age- and sex-matched essential hypertension without renal damage (NRD) and 58 healthy participants (normal) were selected. RESULTS: Our study revealed that C3 and AP50 continuously increased from normal to NRD to RD (p < 0.05, respectively), while CFH was significantly lower than that in NRD and healthy participants (p < 0.05, respectively). After multifactorial logistic regression analysis corrected for confounders, elevated serum C3 (p = 0.001) and decreased CFH (p < 0.001) were found to be independent risk factors for hypertension in healthy participants; elevated serum C3 (p = 0.034), elevated AP50 (p < 0.001), decreased CFH (p < 0.001), increased age (p = 0.011) and increased BMI (p = 0.013) were found to be independent risk factors for the progression of hypertension to hypertensive renal damage; elevated serum C3 (p = 0.017), elevated AP50 (p = 0.023), decreased CFH (p = 0.005) and increased age (p = 0.041) were found to be independent risk factors for the development of hypertensive renal damage in healthy participants. CONCLUSION: Abnormal activation of complement, particularly complement AP, may be a risk factor for the development and progression of hypertensive renal damage.

Canagliflozin attenuates kidney injury, gut-derived toxins, and gut microbiota imbalance in high-salt diet-fed Dahl salt-sensitive rats.

PURPOSE: To investigate the effects of canagliflozin (20 mg/kg) on Dahl salt-sensitive (DSS) rat gut microbiota and salt-sensitive hypertension-induced kidney injury and further explore its possible mechanism. METHODS: Rats were fed a high-salt diet to induce hypertension and kidney injury, and physical and physiological indicators were measured afterwards. This study employed 16S rRNA sequencing technology and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolic profiling combined with advanced differential and association analyses to investigate the correlation between the microbiome and the metabolome in male DSS rats. RESULTS: A high-salt diet disrupted the balance of the intestinal flora and increased toxic metabolites (methyhistidines, creatinine, homocitrulline, and indoxyl sulfate), resulting in severe kidney damage. Canagliflozin contributed to reconstructing the intestinal flora of DSS rats by significantly increasing the abundance of Corynebacterium spp., Bifidobacterium spp., Facklamia spp., Lactobacillus spp., Ruminococcus spp., Blautia spp., Coprococcus spp., and Allobaculum spp. Moreover, the reconstruction of the intestinal microbiota led to significant changes in host amino acid metabolite concentrations. The concentration of uremic toxins, such as methyhistidines, creatinine, and homocitrulline, in the serum of rats was decreased by canagliflozin, which resulted in oxidative stress and renal injury alleviation. CONCLUSION: Canagliflozin may change the production of metabolites and reduce the level of uremic toxins in the blood circulation by reconstructing the intestinal flora of DSS rats fed a high-salt diet, ultimately alleviating oxidative stress and renal injury.

Canagliflozin and irbesartan ameliorate renal fibrosis via the TGF-ß1/Smad signaling pathway in Dahl salt-sensitive rats.

OBJECTIVES: This study assessed the antifibrotic effects of canagliflozin, with or without irbesartan, on renal injury in Dahl salt-sensitive (SS) rats fed a high-salt (HS) diet. METHODS: After the preconditioning stage, Dahl SS rats (n = 47) were divided into five experimental groups as follows: low-salt (LS, n = 7), HS (n = 10), HS with canagliflozin (n = 10), HS with irbesartan (n = 10), and HS with canagliflozin and irbesartan (n = 10). RESULTS: The HS diet increased systolic blood pressure (SBP), renal fibrosis, fibrotic protein expression, and transforming growth factor-ß1 (TGF-ß1)/Smad2/3 pathway protein expression compared with the findings in the LS group. Irbesartan reduced SBP and slowed the loss of renal function. Canagliflozin significantly reduced body weight and renal fibrosis and suppressed the TGF-ß1/Smad2/3 pathway. The combined therapy exerted better renoprotective effects on all outcome parameters. CONCLUSIONS: These results indicate that canagliflozin and irbesartan exert different effects on renal injury in SS hypertensive rats, and the combined regimen could have stronger effects than either monotherapy.

Canagliflozin Ameliorates Ventricular Remodeling through Apelin/Angiotensin-Converting Enzyme 2 Signaling in Heart Failure with Preserved Ejection Fraction Rats.

INTRODUCTION: The aim of this study was to investigate the effect of canagliflozin (CANA) on ventricular remodeling in patients with preserved ejection fraction (HFpEF) heart failure and to further investigate its possible molecular mechanisms. METHODS: A high-salt diet was used to induce the formation of HFpEF model in salt-sensitive rats. The rats were fed with CANA and irbesartan, respectively. The mice were divided into control group, model group, CANA group, irbesartan group, and combined drug group. After 12 weeks of feeding, the rats were evaluated by measuring the relevant indexes and echocardiography for cardiac function. Histological analysis was performed using Masson trichrome staining and immunohistochemical staining. RT-qPCR and Western blot were used to quantify the relevant genes and proteins. RESULTS: In this study, CANA exhibited diuresis, decreased blood pressure, weight loss, and increased food and water intake. Following a high-salt diet, Dahl salt-sensitive rats developed hypertension followed by left ventricular diastolic dysfunction, myocardial fibrosis, and left ventricular remodeling. Myocardial hypertrophy and fibrosis were reduced, and left ventricular diastolic function and ventricular remodeling improved after CANA treatment. The combination of CANA and irbesartan was superior to monotherapy in reducing blood pressure and improving cardiac insufficiency and left ventricular diastolic dysfunction in rats. CANA improves myocardial fibrosis, left ventricular diastolic dysfunction, and ventricular remodeling by upregulating apelin, activating angiotensin-converting enzyme 2 (ACE2), and increasing ACE2/Ang (1-7)/MASR axis levels. CONCLUSION: CANA improves myocardial fibrosis, left ventricular diastolic dysfunction, and ventricular remodeling in HFpEF rats through upregulation of apelin/ACE2 signaling.

MiR-21 attenuates FAS-mediated cardiomyocyte apoptosis by regulating HIPK3 expression.

MicroRNA-21 (miR-21) plays an anti-apoptotic role following ischemia-reperfusion (I/R) injury (IRI) in vivo; however, its underlying mechanism remains unclear. The present study explored the effects of miR-21 and homeodomain interacting protein kinase 3 (HIPK3) on cardiomyocyte apoptosis induced by hypoxia/reoxygenation (H/R) in vitro. To this end, the rat cardiomyocyte H9C2 cell line was exposed to H/R and the roles of miR-21 and HIPK3 in regulating cell viability and apoptosis were evaluated by cell counting kit-8 assay, terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling, and flow cytometry. Immunofluorescence and Western blotting were performed to detect the expression/phosphorylation of apoptosis-related proteins. miR-21 expression was measured with quantitative real-time polymerase chain reaction. The putative interaction between miR-21 and HIPK3 was evaluated using the luciferase reporter assay. Our results showed that (i) miR-21 overexpression or HIPK3 down-regulation significantly attenuated H9C2 cells apoptosis after H/R, (ii) suppression of miR-21 expression promoted apoptosis, (iii) miR-21 overexpression inhibited HIPK3 expression, (iv) HIPK3 was the direct and main target of miR-21, (v) miR-21/HIPK3 formed part of a reciprocal, negative feedback loop, and (vi) HIPK3 down-regulation decreased FAS-mediated apoptosis by inhibiting the phosphorylation of FADD, which subsequently inhibited the expression of BAX and cleaved caspase-3 and increased the expression of BCL2. Our study indicates that miR-21 attenuates FAS-mediated cardiomyocyte apoptosis by regulating HIPK3 expression, which could eventually have important clinical implications for patients with acute myocardial infarction.

Canagliflozin ameliorates epithelial-mesenchymal transition in high-salt diet-induced hypertensive renal injury through restoration of sirtuin 3 expression and the reduction of oxidative stress.

Hypertensive nephropathy is characterized by long-term damage to renal tissues by chronic uncontrolled hypertension, and ultimately leads to the development of renal fibrosis. The epithelial-mesenchymal transition (EMT) potentially contributes to the promotion of renal fibrosis in chronic kidney disease (CKD). In this study, we investigated the potential roles of canagliflozin (Cana) on renal EMT and oxidative stress through its effects on sirtuin 3 (SIRT3) expression. High-salt diet (HSD)-induced Dahl salt-sensitive rats hypertensive renal injury led to decreased SIRT3 expression and an increase in EMT and oxidative stress. In contrast, Cana administration rescued SIRT3 expression, decreased both EMT and levels of oxidative stress, and ameliorated renal injury. Furthermore, we compared the antihypertensive and renoprotective properties of Cana when combined with irbesartan (Irb), a renin-angiotensin system (RAS) blocker. We concluded that administration of Cana in combination with Irb had a significantly greater effect in lowering systolic blood pressure when compared to Cana monotherapy. However, no statistical differences were observed between combined therapy and monotherapy groups with regards to the lowering of diastolic blood pressure and renoprotection. Utilizing the human renal proximal tubular epithelial cell line (HK-2), Angiotensin II (AngⅡ) induced HK-2 negatively regulated the expression of SIRT3, FOXO3a, catalase, and promoted EMT, all of which were reversed by Cana. Furthermore, SIRT3 silencing abolished Cana-mediated rescue of forkhead box O3a (FOXO3a) and catalase expression and Cana-mediated suppression of EMT in AngⅡ induced HK-2. Taken together, Cana acts as a renoprotective agent by suppressing EMT in the pathology of renal fibrosis via interaction with the SIRT3-FOXO3a pathway.

Canagliflozin Attenuates Hepatic Steatosis and Atherosclerosis Progression in Western Diet-Fed ApoE-Knockout Mice.

Purpose: To investigate the effect of canagliflozin (20 mg/kg) on hepatic steatosis and atherosclerosis, and further to explore its possible mechanism. Methods: Blood glucose, blood lipid, oxidative stress response and inflammatory cytokines were examined by intraperitoneal glucose tolerance test and ELISA assay. HE and Oil Red O staining were used to estimate the extent of hepatic steatosis and atherosclerosis. RNA-seq and qRT-PCR were used to further investigate the potential mechanism. The effects of canagliflozin on autophagy were detected using transmission electron microscopy and Western blotting. The endothelial function-related markers were determined by qRT-PCR. Results: Canagliflozin notably alleviated the elevation in blood glucose and insulin resistance in western diet-fed ApoE-/- mice. In ApoE-/-+Cana group, ApoE-/- mice had lower levels of TG, TC, LDL-C, TNF-α, IL-6, IL-1ß, and MCP-1. HE and Oil Red O staining presented that canagliflozin restrained the atherosclerotic plaque development and lipid accumulation. RNA-seq showed that 87 DEGs were relevant to improvement of hepatic steatosis and atherosclerosis by canagliflozin. Among them, CPS1, ASS1, ASL, ARG1, MATLA, GLS2, GOT1, SREBP1, Plin5, Retreg1, and C/EBPß were verified. KEGG enrichment analysis indicated that DEGs were mainly involved in amino acid metabolism. Besides, we observed that canagliflozin reduced the contents of aspartic acid and citrulline in liver. Western blotting showed that ASS1 and p-AMPK/AMPK was remarkably elevated after administration of canagliflozin. Correspondingly, canagliflozin down-regulated SREBP1, FAS, ACC1, HMGCR, p-mTOR/m-TOR, p-ULK1/ULK1 and p62, but up-regulated CPT1, Beclin 1 and LC3 II/LC3I. TEM showed that canagliflozin reduced the number of lipid droplets and increased the autophagosomes. Moreover, we found that canagliflozin elevated the aortic endothelial function-associated markers including ASS1, ASL and eNOS. Conclusion: Canagliflozin may attenuate hepatic steatosis by improving lipid metabolism, enhancing autophagy, and reducing inflammatory response through ASS1/AMPK pathway. Besides, canagliflozin further effectively improves the aortic endothelial function, thereby suppressing atherosclerosis development.

Canagliflozin mitigates ferroptosis and ameliorates heart failure in rats with preserved ejection fraction.

Recently, hypoglycemic drugs belonging to sodium-glucose cotransporter 2 inhibitors (SGLT2i) have generated significant interest due to their clear cardiovascular benefits for heart failure with preserved ejection fraction (HFpEF) since there are no effective drugs that may improve clinical outcomes for these patients over a prolonged period. But, the underlying mechanisms remain unclear, particularly its effects on ferroptosis, a newly defined mechanism of iron-dependent non-apoptotic cell death during heart failure (HF). Here, with proteomics, we demonstrated that ferroptosis might be a key mechanism in a rat model of high-salt diet-induced HFpEF, characterized by iron overloading and lipid peroxidation, which was blocked following treatment with canagliflozin. Data are available via ProteomeXchange with identifier PXD029031. The ferroptosis was evaluated with the levels of acyl-CoA synthetase long-chain family member 4, glutathione peroxidase 4, ferritin heavy chain 1, transferrin receptor, Ferroportin 1, iron, glutathione, malondialdehyde, and 4-hydroxy-trans-2-nonenal. These findings highlight the fact that targeting ferroptosis may serve as a cardioprotective strategy for HFpEF prevention and suggest that canagliflozin may exert its cardiovascular benefits partly via its mitigation of ferroptosis.

An Effective Sodium-Dependent Glucose Transporter 2 Inhibition, Canagliflozin, Prevents Development of Hypertensive Heart Failure in Dahl Salt-Sensitive Rats.

Background: The aim of the study was to investigate the protective effect of canagliflozin (CANA) on myocardial metabolism and heart under stress overload and to further explore its possible molecular mechanism. Methods: High-salt diet was used to induce heart failure with preserved ejection fraction (HFpEF), and then, the physical and physiological indicators were measured. The cardiac function was evaluated by echocardiography and related indicators. Masson trichrome staining, wheat germ agglutinin, and immunohistochemical staining were conducted for histology analysis. Meanwhile, oxidative stress and cardiac ATP production were also determined. PCR and Western blotting were used for quantitative detection of related genes and proteins. Comprehensive metabolomics and proteomics were employed for metabolic analysis and protein expression analysis. Results: In this study, CANA showed diuretic, hypotensive, weight loss, and increased intake of food and water. Dahl salt-sensitive (DSS) rats fed with a diet containing 8% NaCl AIN-76A developed left ventricular remodeling and diastolic dysfunction caused by hypertension. After CANA treatment, cardiac hypertrophy and fibrosis were reduced, and the left ventricular diastolic function was improved. Metabolomics and proteomics data confirmed that CANA reduced myocardial glucose metabolism and increased fatty acid metabolism and ketogenesis in DSS rats, normalizing myocardial metabolism and reducing the myocardial oxidative stress. Mechanistically, CANA upregulated p-adenosine 5'-monophosphate-activated protein kinase (p-AMPK) and sirtuin 1 (SIRT1) and significantly induced the expression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1a). Conclusion: CANA can improve myocardial hypertrophy, fibrosis, and left ventricular diastolic dysfunction induced by hypertension in DSS rats, possibly through the activation of the AMPK/SIRT1/PGC-1a pathway to regulate energy metabolism and oxidative stress.

Comparison of major bleeding events of uninterrupted non-vitamin K antagonist oral anticoagulants versus uninterrupted vitamin K antagonist during catheter ablation of atrial fibrillation: a meta-analysis of randomised controlled trials.

BACKGROUND: Previous meta-analyses comparing major bleeding of uninterrupted non-vitamin K antagonist oral anticoagulants (NOACs) versus uninterrupted vitamin K antagonist (VKA) during catheter ablation (CA) of atrial fibrillation (AF) had no consensus. This meta-analysis was performed to comprehensively evaluate the risk of major bleeding events of these two anticoagulant strategies. METHODS: We searched online databases for randomised controlled trials that compared major bleeding events of uninterrupted NOACs and VKA during CA of AF. A fixed-effect model was used if P-value was > 0.10 and I2 was < 50%, otherwise a random- effect model was used. RESULTS: Six studies including 2392 patients were included in the analysis. The incidence of major bleeding was lower in the NOACs group than in the VKA group (OR = 0.56, 95% CI = 0.34 - 0.93, I2 = 38%, p = 0.15). Subgroup analyses showed that the incidence of severe puncture site complications was lower in the NOACs group than in the VKA group (OR = 0.53, 95% CI = 0.30 - 0.96, I2 = 16%, p = 0.32). But the incidence of cardiac tamponade (OR = 0.53, 95% CI = 0.23 - 1.26, I2 = 0%, p = 0.46), intracranial (OR = 0.25, 95% CI = 0.03 - 2.23, I2 = 0%, p = 0.82) and gastrointestinal bleeding (OR = 0.98, 95% CI = 0.18 - 5.39, I2 = 0%, p = 0.43) had no statistically differences between the two groups. CONCLUSION: This meta-analysis suggests that compared to uninterrupted VKA, uninterrupted NOACs are superior in major bleeding during CA of AF, but this superiority existed only in the aspect of severe puncture site complications.

Corticosteroids significantly increase cystatin C levels in the plasma by promoting cystatin C production in rats.

Background: Several studies have shown that non-renal factors such as corticosteroids may increase plasma cystatin C levels without affecting kidney function. However, the mechanisms underlying this are unclear. We hypothesized that corticosteroids may increase cystatin C levels in the plasma by promoting its production in tissues. In the present study, we aimed to test our hypothesis in rats by investigating the effect of corticosteroids on cystatin C production in tissues and the glomerular filtration rate (GFR), as measured by the gold standard method (i.e., inulin clearance). Results: Dexamethasone treatment was associated with much higher concentrations of cystatin C in all organ tissue homogenates tested. Dexamethasone increased plasma cystatin C levels in rats, without any decrease in renal inulin clearance. The impact of dexamethasone on plasma and organ tissue cystatin C levels was abolished by RU486, indicating the effect was glucocorticoid receptor-mediated. Conclusions: Our study provides direct evidence that corticosteroids may increase cystatin C levels in the plasma by promoting its production, without any decrease in GFR.

Dexamethasone-induced diuresis is associated with inhibition of the renin-angiotensin-aldosterone system in rats.

In heart failure (HF) patients, diuretics remain the cornerstone of therapy to relieve fluid retention. However, the resulting volume loss activates the renin-angiotensin-aldosterone system (RAAS), which blunts the decline in volume depletion and blood pressure. RAAS activation, in turn, compromises the diuretic decongesting effect. Although corticosteroids can induce potent diuresis in HF patients, the effects of corticosteroids on RAAS activation remain unclear. Therefore, we assessed the effects of dexamethasone (Dex) on urine output and plasma angiotensin II and aldosterone levels in rats following water deprivation-induced dehydration, following induction of chronic HF (CHF), and following induction of CHF and volume expansion therapy. In the dehydration model, Dex significantly increased urine output and inhibited dehydration-induced RAAS activation. This favorable effect was abolished by the glucocorticoid receptor antagonist RU486, suggesting involvement of the glucocorticoid receptor. In the CHF model, Dex treatments doubled urine output without activating RAAS. Moreover, in acute volume expansion experiments, Dex pretreatments led to potent diuresis during the pretreatment period and restored renal adaptation to acute volume expansion without activating RAAS in rats with CHF. Collectively, these data show that corticosteroids induce potent diuresis without activating RAAS in rats.

Prednisone lowers serum uric acid levels in patients with decompensated heart failure by increasing renal uric acid clearance.

Clinical studies have shown that large doses of prednisone could lower serum uric acid (SUA) in patients with decompensated heart failure (HF); however, the optimal dose of prednisone and underlying mechanisms are unknown. Thirty-eight patients with decompensated HF were randomized to receive standard HF care alone (n = 10) or with low-dose (15 mg/day, n = 8), medium-dose (30 mg/day, n = 10), or high-dose prednisone (60 mg/day, n = 10), for 10 days. At the end of the study, only high-dose prednisone significantly reduced SUA, whereas low- and medium-dose prednisone and standard HF care had no effect on SUA. The reduction in SUA in high-dose prednisone groups was associated with a significant increase in renal uric acid clearance. In conclusion, prednisone can reduce SUA levels by increasing renal uric acid clearance in patients with decompensated HF.

Corticosteroids Significantly Increase Serum Cystatin C Concentration without Affecting Renal Function in Symptomatic Heart Failure.

BACKGROUND: Human cystatin C is a single non-glycosylated polypeptide chain consisting of 120 amino acid residues. Its concentration in the circulation is mainly determined by glomerular filtration rate. However, non-renal factors, i.e., drugs, may dramatically affect its levels in the circulation. The aim of this study was to evaluate the effect of corticosteroid treatment on serum cystatin C concentration in patients with symptomatic heart failure. METHODS: Fifty-six symptomatic heart failure patients were treated with prednisone. Concentrations of serum cystatin C and serum creatinine were recorded at baseline, and after about 2 weeks of treatment. Twenty-four hour urinary creatinine was also measured to directly calculate glomerular filtration rate. RESULTS: Prednisone treatment significantly increased serum cystatin C concentration from 1.24 +/- 0.40 mg/L at baseline to 1.61 +/- 0.80 mg/L at the end of study (p < 0.05). However, the elevation in serum cystatin C concentration was not associated with renal function impairment. Prednisone not only significantly decreased serum creatinine concentrations from 89.66 +/- 28.63 pmol/L at baseline to 76.55 +/- 20.80 micromol/L after prednisone treatment (p < 0.05), but also significantly increased fractional excretion of sodium and urine flow rate. The data also showed there was a slight and but nonstatistically significant increase in glomerular filtration rate in such patients after prednisone treatment. CONCLUSIONS: Important non-renal factors, such as corticosteroids, can influence cystatin C concentration. Thus, it needs to be considered when interpreting cystatin C values in patients with heart failure receiving corticosteroid therapy.

Effect of Corticosteroid on Renal Water and Sodium Excretion in Symptomatic Heart Failure: Prednisone for Renal Function Improvement Evaluation Study.

BACKGROUND: Recent evidence indicates that prednisone can potentiate renal responsiveness to diuretics in heart failure (HF). However, the optimal dose of prednisone is not known. METHOD: Thirty-eight patients with symptomatic HF were randomized to receive standard HF care alone (n = 10) or with low-dose (15 mg/d, n = 8), medium-dose (30 mg/d, n = 10), or high-dose prednisone (60 mg/d, n = 10), for 10 days. During this time, we recorded the 24-hour urinary output and the 24-hour urinary sodium excretion, at baseline, on day 5 and day 10. We also monitored the change in the concentration of serum creatinine, angiotensin II, aldosterone, high-sensitive C-reactive protein, tumor necrosis factor-α, interleukin 1ß, and interleukin 6. RESULTS: Low-dose prednisone significantly enhanced urine output. However, the effects of medium- and high-dose prednisone on urine output were less obvious. As for renal sodium excretion, high-dose prednisone induced a more potent natriuresis than low-dose prednisone. Despite the potent diuresis and natriuresis induced by prednisone, serum creatinine, angiotensin II, and aldosterone levels were not elevated. These favorable effects were not associated with an inflammatory suppression by glucocorticoids. CONCLUSIONS: Only low-dose prednisone significantly enhanced urine output. However, high-dose prednisone induced a more potent renal sodium excretion than low-dose prednisone.

Prednisone in Uric Acid Lowering in Symptomatic Heart Failure Patients with Hyperuricemia -- The PUSH-PATH3 Study.

OBJECTIVE: To determine the safety and efficacy of prednisone in patients with symptomatic heart failure (HF) and hyperuricemia. METHODS: Prednisone therapy was administered for a short time to 191 symptomatic HF patients with hyperuricemia (serum uric acid > 7 mg/dl). RESULTS: Prednisone significantly reduced serum uric acid by 2.99 mg/dl (p < 0.01) and serum creatinine by 0.17 mg/dl (p < 0.01). These favorable effects were associated with a remarkable increase in urine output, improvement in renal function, and improvement in clinical status. CONCLUSION: Prednisone can be used safely in symptomatic HF patients with hyperuricemia.