Syringaresinol inhibits cardiorenal fibrosis through HSP90 in a cardiorenal syndrome type 2.

BACKGROUND: Syringaresinol processes anti-inflammatory and antioxidative activity. However, the effects of syringaresinol on cardiorenal fibrosis caused by cardiorenal syndrome type 2 (CRS2) are unclear. METHODS: Molecular docking predicted binding activity of syringaresinol to heat shock protein 90 (HSP90). The toxicity of a 4-weeks treatment with 20 mg/kg of syringaresinol was observed by measuring serum pro-inflammatory cytokines levels and by cardiorenal pathology. A CRS2 rad model was established by myocardial infarction using ligation over an 8 week-period. Rats were divided into five groups, including sham, CRS2, pimitespib, syringaresinol, and HSP90 + syringaresinol. Rats were received a 4-weeks daily treatment with 10 mg/kg pimitespib (a HSP90 inhibitor) or 20 mg/kg syringaresinol. Recombinant adeno-associated virus (rAAV) carrying a periostin (PE) promoter driving the expression of wild-type HSP90 (rAAV9-PE-HSP90, 1 × 1011 µg) was treated intravenously once in CRS2 model rats. Cardiorenal function and pathology were assessed. Expressions of HSP90 and TGF-ß1 in the myocardium and kidney were measured by immunohistochemistry and western blotting. RESULTS: Syringaresinol showed good binding activity with HSP90, and no signs of toxicity in rats following treatment. Pimitespib or syringaresinol significantly improved the cardiorenal function and fibrosis in rats with CRS2. Meanwhile, the rAAV9-PE-HSP90 injection obviously blocked the effects of syringaresinol. CONCLUSIONS: Syringaresinol targets HSP90 to suppress CRS2-induced cardiorenal fibrosis, providing a promising therapeutic drug for CRS2.

Attenuation of indoxyl sulfate-induced cell damage by cinchonidine-a Cinchona alkaloid-through the downregulation of p53 signaling pathway by promoting MDM2 cytoplasmic-nuclear shuttling in endothelial cells.

Renocardiac syndromes are a critical concern among patients with chronic kidney disease (CKD). High level of indoxyl sulfate (IS), a protein-bound uremic toxin, in plasma is known to promote the pathogenesis of cardiovascular diseases by impairing endothelial function. However, the therapeutic effects of the adsorbent of indole, a precursor of IS, on renocardiac syndromes is still debated. Therefore, novel therapeutic approaches should be developed to treat IS-associated endothelial dysfunction. In the present study, we have found that cinchonidine, a major Cinchona alkaloid, exhibited superior cell-protective effects among the 131 test compounds in IS-stimulated human umbilical vein endothelial cells (HUVECs). IS-induced cell death, cellular senescence, and impairment of tube formation in HUVECs were substantially reversed after treatment with cinchonidine. Despite the cinchonidine did not alter reactive oxygen species formation, cellular uptake of IS and OAT3 activity, RNA-Seq analysis showed that the cinchonidine treatment downregulated p53-modulated gene expression and substantially reversed IS-caused G0/G1 cell cycle arrest. Although the mRNA levels of p53 were not considerably downregulated by cinchonidine in IS-treated HUVECs, the treatment of cinchonidine promoted the degradation of p53 and the cytoplasmic-nuclear shuttling of MDM2. Cinchonidine exhibited cell-protective effects against the IS-induced cell death, cellular senescence, and impairment of vasculogenic activity in HUVECs through the downregulation of p53 signaling pathway. Collectively, cinchonidine may be a potential cell-protective agent to rescue IS-induced endothelial cell damage.

Molecular and Cellular Mechanisms Involved in Adipose-derived stem cell and their extracellular vesicles in an Experimental Model of Cardio- renal Syndrome type 3: Histological and Biochemical Study.

A cardio-renal syndrome (CRS) is a medical condition in which kidney problems are accompanied by heart problems and diagnosed when acute kidney injury contributes to the development of acute cardiac injury. Regenerative medicine is becoming increasingly interested in adipose stem cells. We evaluated the effect of both adipose-derived stem cell extracellular vesicles (ADSCs-EVs) and adipose stem cells (ADSCs) on an experimental model of CRSIII. In this study, isolation, and further identification of ADSCs and ADSCs-EVs by transmission electron microscopy and flow cytometric analysis. Cardio-renal syndrome in rats was induced by renal artery ligation RAL followed by a single dose injection of both ADSCs and ADSCs-EVs in separate groups. The effects of ADSCs-EVs and ADSCs against induced CRSIII were evaluated by both renal and cardiac oxidant/antioxidant biomarkers, renal function, and mRNA gene expression quantitation for atrial natriuretic peptide (ANP), p300, and myocyte enhancer factor 2 (MEF2C and MEF2A), as well as myocardin (MYOCD), as molecules associated with cardiac hypertrophy. Additionally, histological and immunohistochemical studies of cardiac and renal tissues were done. ADSCs-EVs were effectively isolated and characterized. ADSCs-EVs and ADSCs reversed induced CRSIII, evidenced by considerably decreased serum urea and creatinine levels. Returned oxidant/antioxidant stability, and decreased caspase 3-mediated apoptotic programmed cell death in cardiac and renal tissues. Additionally, they led to successful down-regulation of hypertrophic cardiac genes levels and reversed histopathological cardiac and renal injures. ADSCs-derived extracellular vesicles and ADSCs injection restored damaged cardiac and renal tissue and improved its function greatly following induced CRSIII. They could therefore be useful as a means of protecting the heart from the deleterious effects of acute renal injury and reprogramed injured cardiac cells by activating regenerative processes. SIMPLE SUMMARY: Cardiorenal syndrome (CRS) type III is a subcategory of CRS whereby acute kidney injury (AKI) could contribute to the development of acute cardiac dysfunction. This study provided innovatory data regarding the role of adipose-derived stem cell extracellular vesicles ADSCs-EVs and adipose stem cells (ADSCs) in acute renal and cardiac dysfunction and renal biopsy specimens in the form of interstitial inflammation/tubular degeneration. The main cause of renal and cardiac dysfunction is identified to be the activation and accumulation of inflammatory cells and oxidants in the interstitium, surrounded by increased amounts of extracellular matrix, and ADSCs-EVs have been proposed as a contributor factor. The study has evidenced that both ADSCs-EVs and adipose stem cells display beneficial effects on renal and cardiac tissues survival in terms of the frequent occurrence of cardio-renal syndrome, ADSC-EVs treatment repaired damaged renal and cardiac tissues and recovered their function. ADSC-EVs reversed the effects of cardio-renal syndrome and reprogramed injured cells by activating regenerative processes. The clinical significance of the results presented in future studies needs to be investigated further.

Adipose-derived stem cell and their extracellular vesicles ameliorates immune function, and cardiac markers in experimental model of cardiorenal syndrome type III: TNF-α, IFN-γ and IL-10 cytokine production and their correlation with genotype.

Cardio-renal syndrome (CRS) denotes the convergence of heart-kidney interactions across several mechanisms. The current study is conducted to evaluate the anti-inflammatory role of adipose tissue-derived stem cells (ASCs) versus adipose stem cell-derived extracellular vesicles (ADSCs-EVs) in experimental model of cardiorenal syndrome type III. The study was conducted on 50 male rats that were equally divided to: group I (control group); Group II (experimental cardiorenal syndrome group) which induced by right renal artery ligation (ICRSIII); Group III (Sham-operated control group) which underwent surgical incision without renal artery ligation; Group IV (ICRSIII which received ADSCs-extracellular vesicles (ADSCs-EVs); Group V (ICRSIII which received adipose tissue stem cells (ASCs). Assessment of pro-inflammatory cytokines; IL-10, IL-1α, IL-6, IL-1 ß, IFN-γ, NF-α and their mRNA gene expression quantitation, (NGAL), and brain natriuretic peptide (BNP) as markers of cardiac dysfunction, as well as histopathological examination of renal tissue was examined by H& E, Masson trichrome and periodic acid-Schiff stains (PAS). The ICRS group exhibited significant acute tubular injury with tubular dilation, loss of brush borders, epithelial flattening, and occasional sloughed cells in lumen. Use of either ADSCs-EVs or ASCs significantly ameliorated the histological findings of tubular injury. Proinflammatory cytokines, BNP and NGAL were significantly elevated in ICRSIII group as compared to all other studied groups. Administration of ADSCs-EVs or ASCs led to significant decrease in all proinflammatory cytokines as well as BNP and NGAL levels with no significant difference between them. In conclusion, ADSCs-EXs and ASCs exhibited significant repairing effects in experimental-induced cardiorenal syndrome type III as evidenced by amelioration of histological findings of tubular injury, anti-inflammatory effects, and the significant decrease in markers of cardiac dysfunction. ADSC-EVs reprogramed injured cardiac cells by activating regenerative processes.

Combined levosimendan and Sacubitril/Valsartan markedly protected the heart and kidney against cardiorenal syndrome in rat.

BACKGROUND: Cardiorenal syndrome (CRS) remains the leading cause of death in hospitalized patients for all disease entities. Sacubitril/Valsartan (Sac/Val) therapy has been proved to improve prognostic outcome in patients with heart failure or chronic kidney disease. This study tested the hypothesis that combined levosimendan and Sac/Val was superior to just one therapy on protecting the heart and kidney against simultaneous heart and kidney ischemia (I) (for 50-min)-reperfusion (R) (for 7-days) (i.e., double IR) injury (defined as CRS). METHODS AND RESULTS: Adult-male Spraque-Dawley rats (n = 40) were equally categorized into group 1 (sham-operated control), group 2 (double IR), group 3 [double IR+levosimendan (10 mg/kg by intra-peritoneum administration at 30 min/followed by days 1-5 once daily after IR procedure)], group 4 [double IR+Sac/Val (10 mg/kg, orally at 30 min/followed by days 1-5 twice daily after IR procedure)], and group 5 (double IR+Sac/Val+levosimendan). By day 7 after double-IR, the left-ventricular-ejection fraction (LVEF)/left-ventricular-fraction-shortening (LVFS) were highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3/4, but they showed no difference between groups 3/4, whereas the circulatory heart-failure (brain-natriuretic peptide)/proinflammatory (suppression of tumorigenicity-2) biomarkers, blood-urea-nitrogen/creatinine and ratio of urine protein to creatinine (all p < 0.0001) exhibited an opposite pattern of LVEF among the groups. The protein expressions of inflammatory (tumor necrosis factor-α/interleukin-1ß/matrix metalloproteinase-9)/oxidative-stress (NOX-1/NOX-2/NOX-4)/apoptotic (mitochondrial-Bax/caspase-3/poly-(ADP-ribose)-polymerase)/fibrotic (Smad3/transforming growth factor-ß)/mitochondrial-damaged (cytosolic-cytochrome-C)/myocardial-hypertrophic (ß-MHC) biomarkers in LV myocardium exhibited an opposite pattern of LVEF among the groups (all p < 0.0001). The cellular expressions of inflammatory (CD68)/DNA-damaged (γ-H2AX) biomarkers and infarct/fibrotic areas in LV myocardium and kidney displayed an opposite pattern of LVEF among the groups (all p < 0.0001). CONCLUSION: Combined levosimendan and Sac/Val was superior to merely one therapy on protecting the heart and kidney as well as preserving their functions against double IR injury.

Comparative cardioprotective effects of carvedilol versus atenolol in a rat model of cardiorenal syndrome type 4.

The incidence of chronic kidney disease is escalating; cardiorenal syndrome (CRS) type 4 is gaining a major health concern causing significant morbidity and mortality, putting major burdens on the healthcare system. This study was designed to compare the cardioprotective effects of carvedilol versus atenolol against CRS type 4 induced by subtotal 5/6 nephrectomy in rats and to explore the underlying mechanisms. Immediately after surgery, carvedilol (20 mg/kg/day) or atenolol (20 mg/kg/day) was added to drinking water for 10 weeks. Carvedilol was more effective than atenolol in improving kidney functions, decreasing elevated blood pressures, attenuating cardiac hypertrophy, reducing serum brain natriuretic peptide, and diminished cardiac fibrous tissue deposition. However, carvedilol was equivalent to atenolol in modulating ß1-adrenergic receptors (ß1ARs) and cardiac diacylglycerol (DAG) signaling, but carvedilol was superior in modulating ß-arrestin2, phosphatidyl inositol 4,5 bisphosphates (PIP2), and caspase 3 levels. Carvedilol has superior cardioprotective effects than atenolol in a rat model of CRS type 4. These protective effects are mediated through modulating cardiac ß1ARs/ß-arrestin2/PIP2/DAG as well as abating cardiac apoptotic signaling pathways (caspase3/pS473 protein kinase B (Akt)).

Tyrosine and Tryptophan vibrational bands as markers of kidney injury: a renocardiac syndrome induced by renal ischemia and reperfusion study.

Renal injury caused by renal ischemia and reperfusion strongly influences heart morphology, electrophysiology, and redox unbalance. The so-called cardiorenal syndrome is an important class of dysfunction since heart and kidneys are responsible for hemodynamic stability and organ perfusion through a complex network. In the present work we investigate the vibrational spectral features probed by Fourier-Transform Raman (FT-Raman) spectroscopy due to physiological alterations induced by renal ischemic reperfusion aiming to detect molecular markers related to progression of acute to chronic kidney injury and mortality predictors as well. C57BL/6J mice were subjected to unilateral occlusion of the renal pedicle for 60 min and reperfusion for 5, 8, and 15 days. Biopsies of heart and kidney tissues were analyzed. Our findings indicated that cysteine/cystine, fatty acids, methyl groups of Collagen, α-form of proteins, Tyrosine, and Tryptophan were modulated during renal ischemia and reperfusion process. These changes are consistent with fibroblast growth factors and Collagen III contents changes. Interestingly, Tyrosine and Tryptophan, precursor molecules for the formation of uremic toxins such as indoxyl sulfate and p-cresyl sulfate were also modulated. They are markers of kidney injury and their increase is strongly correlated to cardiovascular mortality. Regarding this aspect, we notice that monitoring the Tyrosine and Tryptophan bands at 1558, 1616, and 1625 cm-1 is a viable and and advantageous way to predict fatality in cardiovascular diseases both "in vivo" or "in vitro", using the real-time, multiplexing, and minimally invasive advantages of FT-Raman spectroscopy.

HE4 Predicts Progressive Fibrosis and Cardiovascular Events in Patients With Dilated Cardiomyopathy.

Background Cardiac fibrosis plays a crucial role in the pathogenesis of dilated cardiomyopathy (DCM). HE4 (human epididymis protein 4) is a secretory protein expressed in activated fibroblasts that exacerbates tissue fibrosis. In the present study, we investigated the clinical utility of HE4 measurement in patients with DCM and its pathophysiological role in preclinical experiments in vivo and in vitro. Methods and Results We measured serum HE4 levels of 87 patients with DCM. Endomyocardial biopsy expressed severe fibrosis only in the high HE4 group (P<0.0001). Echocardiography showed that left ventricular end-diastolic diameter tends to decrease over time (58±7.3 to 51±6.6 mm; P<0.0001) in the low HE4 group (<59.65 pmol/L [median value]). HE4 was significantly associated with risk reduction of mortality and cardiovascular hospitalization in multivariate Cox model. In vivo, HE4 was highly expressed in kidney and lung tissue of mouse, and scarcely expressed in heart. In genetically induced DCM mouse model, HE4 expression increased in kidney but not in heart and lung. In vitro, supernatant from HE4-transfected human embryonic kidney 293T cells enhanced transdifferentiation of rat neonatal fibroblasts and increased expression of fibrosis-related genes, and this was accompanied by the activation of extracellular signal-regulated kinase signaling in cardiac fibroblasts. Treatment with an inhibitor of upstream signal of extracellular signal-regulated kinase or a neutralizing HE4 antibody canceled the profibrotic properties of HE4. Conclusions HE4 functions as a secretory factor, activating cardiac fibroblasts, thereby inducing cardiac interstitial fibrosis. HE4 could be a promising biomarker for assessing ongoing fibrosis and a novel therapeutic target in DCM. Registration URL: https://upload.umin.ac.jp/cgi-open-bin/ctr; Unique identifier: UMIN000043062.

Vascular growth factors as potential new treatment in cardiorenal syndrome in diabetes.

BACKGROUND: Cardiorenal syndrome in diabetes is characterised by alterations of the cardiovascular system paralleled by kidney disease with progressive renal function decline. In diabetes, chronic metabolic and haemodynamic perturbations drive endothelial dysfunction, inflammation, oxidative stress and progressive tissue fibrosis which, in turn, lead to heart and renal anatomo-functional damage. In physiology, vascular growth factors have been implicated in vascular homeostasis; their imbalance, in disease setting such as diabetes, leads to vascular dysfunction and cardiorenal damage. AIMS: To define the role of vascular growth factors and angiopoietins in cardiorenal syndrome. MATERIAL AND METHODS: We will focus on the two most studied vascular growth factors, vascular endothelial growth factor (VEGF) and angiopoietins (Angpt). The balance and crosstalk between these growth factors are important in organ development and in the maintenance of a healthy vasculature, heart and kidney. The observed alterations in expression/function of these vascular growth factors, as seen in diabetes, are a protective response against external perturbations. RESULTS: The chronic insults driving diabetes-mediated cardiorenal damage results in a paradoxical situation, whereby the vascular growth factors imbalance becomes a mechanism of disease. Studies have explored the possibility of modulating the expression/action of vascular growth factors to improve disease outcome. Experimental work has been conducted in animals and has been gradually translated in humans. DISCUSSION: Difficulties have been encountered especially when considering the magnitude, timing and duration of interventions targeting a selective vascular growth factor. Targeting VEGF in cardiovascular disease has been challenging, while modulation of the Angpt system seems more promising. CONCLUSION: Future studies will establish the translatability of therapies targeting vascular growth factors for heart and kidney disease in patients with diabetes.

TWEAK-Fn14 as a common pathway in the heart and the kidneys in cardiorenal syndrome.

There is a complex relationship between cardiac and renal disease, often referred to as the cardiorenal syndrome. Heart failure adversely affects kidney function, and both acute and chronic kidney disease are associated with structural and functional changes to the myocardium. The pathological mechanisms and contributing interactions that surround this relationship remain poorly understood, limiting the opportunities for therapeutic intervention. The cytokine tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor, fibroblast growth factor-inducible 14 (Fn14), are abundantly expressed in injured kidneys and heart. The TWEAK-Fn14 axis promotes responses that drive tissue injury such as inflammation, proliferation, fibrosis, and apoptosis, while restraining the expression of tissue protective factors such as the anti-aging factor Klotho and the master regulator of mitochondrial biogenesis peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). High levels of TWEAK induce cardiac remodeling, and promote inflammation, tubular and podocyte injury and death, fibroblast proliferation, and, ultimately, renal fibrosis. Accordingly, targeting the TWEAK-Fn14 axis is protective in experimental kidney and heart disease. TWEAK has also emerged as a biomarker of kidney damage and cardiovascular outcomes and has been successfully targeted in clinical trials. In this review, we update our current knowledge of the roles of the TWEAK-Fn14 axis in cardiovascular and kidney disease and its potential contribution to the cardiorenal syndrome. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Associations of urinary polymeric immunoglobulin receptor peptides in the context of cardio-renal syndrome.

The polymeric immunoglobulin receptor (pIgR) transports immunoglobulins from the basolateral to the apical surface of epithelial cells. PIgR was recently shown to be associated with kidney dysfunction. The immune defense is initiated at the apical surface of epithelial cells where the N-terminal domain of pIgR, termed secretory component (SC), is proteolytically cleaved and released either unbound (free SC) or bound to immunoglobulins. The aim of our study was to evaluate the association of pIgR peptides with the cardio-renal syndrome in a large cohort and to obtain information on how the SC is released. We investigated urinary peptides of 2964 individuals available in the Human Urine Proteome Database generated using capillary electrophoresis coupled to mass spectrometry. The mean amplitude of 23 different pIgR peptides correlated negatively with the estimated glomerular filtration rate (eGFR, rho = -0.309, p < 0.0001). Furthermore, pIgR peptides were significantly increased in cardiovascular disease (coronary artery disease and heart failure) after adjustment for eGFR. We further predicted potential proteases involved in urinary peptide generation using the Proteasix algorithm. Peptide cleavage site analysis suggested that several, and not one, proteases are involved in the generation of the SC. In this large cohort, we could demonstrate that pIgR is associated with the cardio-renal syndrome and provided a more detailed insight on how pIgR can be potentially cleaved to release the SC.

Circulating miRNA-21 as a diagnostic biomarker in elderly patients with type 2 cardiorenal syndrome.

Circulating miRNAs have attracted attention as serum biomarkers for several diseases. In this study, we aimed to evaluate the diagnostic value of circulating miRNA-21 (miR-21) as a novel biomarker for elderly patients with type 2 cardiorenal syndrome (CRS-2). A total of 157 elderly patients with chronic heart failure (CHF) were recruited for the study. According to an estimated glomerular filtration rate (eGFR) cut-off of 60 ml/min/1.73 m2, 84 patients (53.5%) and 73 patients (46.5%) were assigned to the CRS group and the CHF group, respectively. Expression levels of serum miR-21 and biomarkers for CRS, such as kidney injury factor-1 (KIM-1), neutrophil gelatinase-related apolipoprotein (NGAL), cystatin C (Cys C), amino-terminal pro-B-type natriuretic peptide (NT-proBNP), N-acetyl-κ-D-glucosaminidase (NAG), and heart-type fatty acid-binding protein (H-FABP), were detected. Serum miR-21, KIM-1, NGAL, Cys C, NT-proBNP and H-FABP levels were significantly higher in the CRS group than in the CHF group (P < 0.01), whereas NAG expression was not significantly different between the two groups (P > 0.05). Cys C, H-FABP and eGFR correlated significantly with miR-21 expression, but correlations with miR-21 were not significant for NT-proBNP, NGAL, NAG and KIM-1. Moreover, multivariate logistic regression found that serum miR-21, increased serum Cys C, serum KIM-1, hyperlipidaemia and ejection fraction (EF) were independent influencing factors for CRS (P < 0.05). The AUC of miR-21 based on the receiver operating characteristic (ROC) curve was 0.749, with a sensitivity of 55.95% and a specificity of 84.93%. Furthermore, combining miR-21 with Cys C enhanced the AUC to 0.902, with a sensitivity of 88.1% and a specificity of 83.6% (P < 0.001). Our findings suggest that circulating miR-21 has medium diagnostic value in CRS-2. The combined assessment of miR-21 and Cys C has good clinical value in elderly patients with CRS-2.

The guanylate cyclase C agonist linaclotide ameliorates the gut-cardio-renal axis in an adenine-induced mouse model of chronic kidney disease.

BACKGROUND: Cardiorenal syndrome is a major cause of mortality in patients with chronic kidney disease (CKD). However, the involvement of detrimental humoral mediators in the pathogenesis of cardiorenal syndrome is still controversial. Trimethylamine-N-oxide (TMAO), a hepatic metabolic product of trimethylamine generated from dietary phosphatidylcholine or carnitine derived by the gut microbiota, has been linked directly with progression of cardiovascular disease and renal dysfunction. Thus, targeting TMAO may be a novel strategy for the prevention of cardiovascular disease and chronic kidney disease. METHODS: Linaclotide, a guanylate cyclase C agonist, was administered to adenine-induced renal failure (RF) mice and changes in renal function and levels of gut-derived uremic toxins, as well as the gut microbiota community, were analyzed using metabolomic and metagenomic methods to reveal its cardiorenal effect. RESULTS: Linaclotide decreased the plasma levels of TMAO at a clinically used low dose of 10 µg/kg in the adenine-induced RF mouse model. At a high concentration of 100 µg/kg, linaclotide clearly improved renal function and reduced the levels of various uremic toxins. A reduction in TMAO levels following linaclotide treatment was also observed in a choline-fed pro-atherosclerotic model. Linaclotide ameliorated renal inflammation and fibrosis and cardiac fibrosis, as well as decreased the expression of collagen I, transforming growth factor-ß, galectin-3 (Gal-3) and ST2 genes. Plasma levels of Gal-3 and ST2 were also reduced. Because exposure of cardiomyocytes to TMAO increased fibronectin expression, these data suggest that linaclotide reduced the levels of TMAO and various uremic toxins and may result in not only renal, but also cardiac, fibrosis. F4/80-positive macrophages were abundant in small intestinal crypts in RF mice, and this increased expression was decreased by linaclotide. Reduced colonic claudin-1 levels were also restored by linaclotide, suggesting that linaclotide ameliorated the 'leaky gut' in RF mice. Metagenomic analysis revealed that the microbial order Clostridiales could be responsible for the change in TMAO levels. CONCLUSION: Linaclotide reduced TMAO and uremic toxin levels and could be a powerful tool for the prevention and control of the cardiorenal syndrome by modification of the gut-cardio-renal axis.

Lipopolysaccharide in systemic circulation induces activation of inflammatory response and oxidative stress in cardiorenal syndrome type 1.

BACKGROUND: Cardiorenal syndrome type 1 (CRS type 1) is characterized by a rapid worsening of cardiac function leading to acute kidney injury. In this study, we evaluate the role of lipopolysaccharide (LPS) and various inflammatory markers in the developing acute kidney injury (AKI) in acute heart failure (AHF) patients. METHODS: We enrolled 31 AHF patients and 20 CRS type 1 (the cause of AKI was presumed to be related to cardiac dysfunction) and 17 healthy volunteers without AHF, AKI or CKD, as control group (CTR). We assessed levels of LPS, proinflammatory cytokines (TNF-α, IL-6, IL-18), and oxidative stress marker (myeloperoxidase, MPO). RESULTS: We observed a significant increase in LPS, TNF-α, IL-6, IL-18 and MPO levels in CRS type 1 and AHF group compared to CTR. LPS levels resulted significantly higher in CRS type 1 patients compared with AHF (118.2 pg/mL, IQR 77.8-217.6 versus 13.5 pg/mL, IQR 12.0-17.0, p = 0.008). We found a cytokines and oxidative stress dysregulation in CRS type 1 patients compared with AHF. Furthermore, we observed a strong positive significant correlation between LPS levels and IL-6 (Spearman's rho = 0.79, p < 0.001), and IL-18 (Spearman's rho = 0.77, p < 0.001) and MPO (Spearman's rho = 0.80, p < 0.001), all confirm by simple linear regression analysis. CONCLUSION: CRS type 1 patients presented an increased level of LPS, pro-inflammatory cytokines, and MPO. Furthermore, there is a direct correlation between LPS and pro-inflammatory cytokines and stress oxidative marker. LPS may play a role in the pathophysiology of CRS type 1 inducing inflammation, oxidative stress and finally kidney damage.

Spironolactone inhibits endothelial-mesenchymal transition via the adenosine A2A receptor to reduce cardiorenal fibrosis in rats.

AIMS: The mechanisms underlying cardiorenal syndromes are complex and not fully understood; Fibrosis seems to be a primary driver of the diseases' pathophysiology. Spironolactone can reduce cardiac or renal fibrosis by inhibiting endothelial-mesenchymal transition (EndMT). Spironolactone protection may rely on activation of adenosine receptors, but the role of the adenosine A2A receptor (A2AR) is unclear. We hypothesize that spironolactone may modulate A2AR to suppress EndMT and reduce cardiorenal remodeling. MAIN METHODS: A model of renal injury followed by heart failure was established by subcutaneous administration of isoprenaline (Iso) to rats. Assessment of cardiac and renal function, fibrosis, EndMT markers, adenosine and A2AR expression was performed. TGF-ß was used to induce EndMT in primary human umbilical vein endothelial cells (HUVECs). Rats or cells were divided into four groups: those that treated with spironolactone alone or in combination with A2AR antagonist ZM241385 or neither, and compared to normal controls. KEY FINDINGS: Isoprenaline-treated rats exhibited cardiac and renal fibrosis, impaired cardiac and renal function, enhanced EndMT, and lower A2AR expression. Spironolactone significantly up-regulated A2AR expression and inhibited EndMT in vivo and in vitro. Moreover, spironolactone improved cardiorenal remodeling and reduced dysfunction. These changes were exacerbated by administration of ZM241385. Together, these findings show that spironolactone up-regulated A2AR to reduce EndMT and ameliorate cardiorenal fibrosis. SIGNIFICANCE: The anti-fibrotic effects of spironolactone may partly depend on the up-regulation of A2AR, and that A2AR might be a potential therapeutic target for the treatment of cardiorenal syndrome.

Cardiorenal status using amino-terminal pro-brain natriuretic peptide and cystatin C on cardiac resynchronization therapy outcomes: From the BIOCRT Study.

BACKGROUND: Cardiorenal syndrome comprises a heterogeneous group of disorders characterized by acute or chronic cardiac and renal dysfunction. OBJECTIVE: The purpose of this study was to determine the effect of cardiorenal status using a dual-marker strategy with amino-terminal pro-brain natriuretic peptide (NT-proBNP) and cystatin C on cardiac resynchronization therapy (CRT) outcomes. METHODS: In 92 patients (age 66 ± 13 years; 80% male; left ventricular ejection fraction 26% ± 7%), NT-proBNP and cystatin C levels were measured at CRT implantation and at 1 month. NT-proBNP >1000 pg/mL and cystatin C >1 mg/L were considered high. Baseline cardiorenal patients were defined as having high NT-proBNP and cystatin C. At 1 month, CRT patients were categorized as (1) irreversible cardiorenal if cystatin C was persistently high; (2) progressive cardiorenal with transition from low to high cystatin C; (3) reversible cardiorenal with transition from high to low cystatin C; and (4) "normal" with stable low cystatin C. Outcomes were 6-month clinical and echocardiographic CRT response and 2 -year major adverse cardiovascular event (MACE). RESULTS: Compared to patients with low NT-proBNP and cystatin C, cardiorenal patients had >9-fold increase risk of CRT nonresponse (odds ratio uncompensated 9.0; compensated 36.4; both P ≤.004) and >6-fold risk of MACE (hazard ratio uncompensated 8.5; P = .005). Compared to "normal" and reversible patients (referent), irreversible patients had a 9-fold increase for CRT nonresponse (odds ratio 9.1; P <.001) and had >4-fold risk of MACE (adjusted hazard ratio 5.1; P <.001). Irreversible patients were most likely echocardiographic CRT nonresponders. CONCLUSION: Cardiorenal status by NT-proBNP and cystatin C can identify high-risk CRT patients, and those with both elevated concentrations have worse prognosis.

Kidney Response to Heart Failure: Proteomic Analysis of Cardiorenal Syndrome.

BACKGROUND/AIMS: Chronic heart failure (HF) disrupts normal kidney function and leads to cardiorenal syndrome that further promotes HF progression. To identify potential participants in HF-related injury, we analyzed kidney proteome in an established HF model. METHODS: HF was induced by chronic volume overload in male HanSD rats using aorto-caval fistula. After 21 weeks, cardiac and renal functions (in-situ kidney study) and renal proteomics were studied in sham-operated (controls) and HF rats, using iTRAQ labeling and LC-MS with Orbitrap Fusion, leading to identification and quantification of almost 4000 proteins. RESULTS: Compared to controls, HF rats had cardiac hypertrophy, systemic and pulmonary congestion. Kidneys of HF rats had reduced renal blood flow, sodium excretion and urine production. While glomerular filtration rate, serum cystatin C and creatinine were still normal compared to controls, HF kidneys showed albuminuria and markedly increased tissue angiotensin-II levels (5-fold). HF kidneys (versus controls) displayed differential expression (˃1.5-fold) of 67 proteins. The most upregulated were angiotensin-converting enzyme (ACE, ˃20-fold), advanced glycosylation product-specific receptor (RAGE, 14-fold), periostin (6.8-fold), caveolin-1 (4.5-fold) and other proteins implicated in endothelial function (vWF, cavins 1-3, T-kininogen 2), proinflammatory ECM activation (MFAP4, collagen-VI, galectin-3, FHL-1, calponin) and proteins involved in glomerular filtration membrane integrity (CLIC5, ZO-1). Carboxylesterase-1D (CES1D), an enzyme that converts ACE inhibitors or sacubitril into active drugs, was also upregulated in HF kidneys. CONCLUSION: Chronic HF leads to latent kidney injury, associated with deep changes in kidney protein composition. These alterations may act in concert with intrarenal renin-angiotensin system activation and may serve as markers and/or targets to tackle cardiorenal syndrome.

Qiliqiangxin Protects against Renal Injury in Rat with Cardiorenal Syndrome Type I through Regulating the Inflammatory and Oxidative Stress Signaling.

Cardiorenal syndrome (CRS) is a frequently encountered clinical condition when the dysfunction of either the heart or kidneys amplifies the failure progression of the other organ. CRS remains a major global health problem. Qiliqiangxin (QLQX) is a traditional Chinese herbs medication, which can improve cardiac function, urine volume, and subjective symptoms in patients with chronic heart failure. In the present study, we aim to investigate the role of QLQX in the treatment of CRS type I and the possible mechanism through establishment of a rat model of myocardial infarction. Rats in CRS-Q group were orally treated with QLQX daily for 2 weeks or 4 weeks, while in sham group and CRS-C group were treated with saline at the same time. Enzyme-linked immunosorbent assay (ELISA) analysis showed that QLQX significantly reduced the levels of angiotensin II (AngII), brain natriuretic peptides (BNP), creatinine (CRE), cystatin C (CysC), tumor necrosis factor (TNF)-α, interleukin (IL)-6, microalbuminuria (MAU), and neutrophil gelatinase-associated lipocalin (NGAL) in plasma induced by myocardial infarction. Western blot analysis showed that QLQX significantly reduced the expressions of AngII, non-phagocytic cell oxidase (NOX)2, and B-cell lymphoma (Bcl)2 associated X protein (Bax), and increased the expressions of Bcl2 and Angiotensin II Type 1 receptor (ATR) in the kidney as compared with the CRS-C group. Fluorescence microscopy showed that the content of reactive oxygen species (ROS) was significantly reduced in the kidney as compared with the CRS-C group. We also examined the apoptosis level in kidney by using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining, and the result showed that QLQX significantly reduced the apoptosis level in kidney induced by myocardial infarction. Taken together, we suggest that QLQX may be a potentially effective drug for the treatment of CRS by regulating inflammatory/oxidative stress signaling.

Altered expression of intestinal duodenal cytochrome b and divalent metal transporter 1 might be associated with cardio-renal anemia syndrome.

The interaction among heart failure (HF), chronic kidney disease (CKD), and anemia is called cardio-renal anemia syndrome. The mechanism of anemia in cardio-renal anemia syndrome is complex and remains completely unknown. We have previously reported that impaired intestinal iron transporters may contribute to the mechanism of anemia in HF using in vivo HF model rats. In this study, we assessed intestinal iron transporters in CKD model rats to investigate the association of intestinal iron transporters in the mechanism of cardio-renal anemia syndrome. CKD was induced by 5/6 nephrectomy in Sprague-Dawley rats. Sham-operated rats served as a control. After 24-week surgery, CKD rats exhibited normocytic normochromic anemia and normal serum erythropoietin levels despite of anemia. Serum iron levels were decreased in CKD rats compared with the controls. Of interest, intestinal expression of critical iron importers, such as duodenal cytochrome b (Dcyt-b) and divalent metal transporter 1 (DMT-1), was decreased in CKD rats compared with the controls. On the other hand, intestinal expression of ferroportin, an intestinal iron exporter, was not different in the control and CKD groups. Moreover, hepatic expression of hepcidin, a regulator of iron homeostasis, did not differ between the control and CKD groups. These results suggest that impaired intestinal expression of Dcyt-b and DMT-1 might be associated with the reduction of an iron uptake in CKD. Taken together, impaired these intestinal iron transporters may become a novel therapeutic target for cardio-renal anemia syndrome.

Biochemical and electrocardiographic studies on the beneficial effects of gallic acid in cyclophosphamide-induced cardiorenal dysfunction.

Background Cardiac toxicity is one of the life-threatening complications of cancer therapy. Cyclophosphamide (CYP) is an alkylating agent with potent antineoplastic and immunosuppressive properties and possibly the most widely used antineoplastic agent. Chronic cardiotoxicity associated with CYP is characterized by progressive heart failure developing from weeks to years after therapy. Methods In this study, rats were administered with (60 mg/kg and 120 mg/kg) alone or in combination with single intraperitoneal (200 mg/kg) administration of CYP for 7 days. CYP was only administered on day 1. Results The administration of CYP led to a significant (p<0.05) increase in cardiac and renal malondialdehyde (MDA) contents and hydrogen peroxide (H2O2) generation. Also, the activities of catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) levels were significantly (p<0.05) reduced following CYP treatment. A significant (p<0.05) increase in serum myeloperoxidase (MPO) activity was recorded in rats administered CYP only. Electrocardiogram (ECG) showed a significant (p<0.05) increase in heart rate (HR) accompanied by transient decrease in QRS duration. Histologic examination revealed architectural anarchy of both heart and kidney of rats that received only CYP. Conclusions In this study, treatment with gallic acid (60 mg/kg and 120 mg/kg) restored the enzymic and non-enzymic antioxidants and also attenuated cardiotoxic and nephrotoxic effect of CYP through free radical scavenging activity, anti-inflammatory and improvement of antioxidant defence system.