Effects of RAAS Inhibitors in Patients with Kidney Disease

Association between proteinuria changes and colorectal cancer incidence: evidence from a nationwide cohort study

BACKGROUND

The presence of excess proteins in the urine, known as proteinuria, has been linked to various health conditions, including chronic kidney disease and cancer. Emerging evidence suggests an association between proteinuria and colorectal cancer, a leading global cause of cancer-related morbidity and mortality. However, the impact of changes in proteinuria status on colorectal cancer risk remains unclear. Understanding this relationship may identify proteinuria as a modifiable risk factor for colorectal cancer prevention.

METHODS

This retrospective cohort study analyzed data from 3,043,138 adults aged over 19 years who participated in biennial health screenings by the South Korean National Health Insurance Service in 2010 and 2012. Participants were classified into four groups based on changes in proteinuria status: no proteinuria, newly developed proteinuria, recovered proteinuria, and persistent proteinuria. Proteinuria was measured using dipstick urinalysis, and colorectal cancer diagnoses were identified using medical records. Cox proportional hazards models adjusted for age, sex, body mass index, lifestyle behaviors, and other confounders were used to estimate cancer risk.

RESULTS

Over a median follow-up period of 9.19 years, 36,846 participants (1.2%) developed colorectal cancer. After adjusting for multiple confounding factors, including age, sex, lifestyle behaviors, medication use, diabetes, hypertension, dyslipidemia, and chronic kidney disease, the persistent proteinuria group demonstrated a significantly higher risk of colorectal cancer compared with the proteinuria-free group (adjusted hazard ratio [aHR], 1.27; 95% CI, 1.13-1.42). Additionally, greater severity of proteinuria was associated with progressively increased colorectal cancer risk (aHR for overt proteinuria [+ 2 to + 4], 1.17; 95% CI, 1.05-1.29).

CONCLUSIONS

Changes in proteinuria status are significantly associated with colorectal cancer risk. Persistent proteinuria poses the highest risk, while transient proteinuria also elevates risk compared to individuals without proteinuria. Regular monitoring and management of proteinuria could potentially be beneficial in identifying individuals at higher colorectal cancer risk, suggesting its possible role as an indicator for targeted prevention strategies. However, further research, including randomized controlled trials, is necessary to confirm any causal relationship.

Efficacy and safety of guselkumab in patients with active lupus nephritis: results from a phase 2, randomized, placebo-controlled study

OBJECTIVE

Evaluate the efficacy and safety of guselkumab, an IL-23p19-subunit inhibitor, in a phase 2, multicentre, randomized, double-blind, placebo-controlled study of patients with active LN.

METHODS

Adults (18-75 years) with active LN [Class III-IV proliferative nephritis (kidney biopsy) and urine protein-to-creatinine ratio (UPCR) of ≥1 mg/mg despite standard-of-care therapy] were randomized (1:1; planned sample = 60) to receive i.v. infusions of guselkumab 400 mg or placebo at weeks 0, 4 and 8, then s.c. injections (guselkumab 200 mg or placebo) at week 12 and every 4 weeks through week 48 in addition to their background therapy. The primary endpoint was achievement of ≥50% decrease in proteinuria from baseline at week 24. Major secondary endpoints (week 24) were achievement of complete renal response (CRR), sustained reduction in steroid dose (≤10 mg/day prednisone/equivalent) from weeks 16-24, UPCR <0.5 mg/mg; <0.75 mg/mg, time to achieving CRR, and time to treatment failure. Safety was assessed through the end of the study.

RESULTS

Following enrolment challenges (COVID-19 pandemic; Ukraine/Russia crisis), the sponsor terminated the study early; 33 participants were randomized (placebo, n = 16; guselkumab, n = 17). At week 24, 56.3% (9/16) in the placebo group and 35.3% (6/17) in the guselkumab group achieved the primary endpoint. No apparent differences were observed in the secondary endpoints. Through end-of-study, 75% of placebo patients and 71% of guselkumab patients reported ≥1 adverse event; most were of mild-to-moderate severity.

CONCLUSION

Guselkumab+background therapy did not demonstrate superior reduction in proteinuria vs placebo+background therapy in this small cohort of patients with active LN. Safety results were consistent with the known safety profile of guselkumab.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04376827.

Predictors of hyperkalemia in pediatric patients on dialysis: international prospective observational study

BACKGROUND

Hyperkalemia is an important issue in kidney failure. The aim of the study was to investigate the predictors of hyperkalemia in children receiving maintenance dialysis.

METHODS

This was an international prospective cross-sectional observational study involving patients < 18 years receiving chronic hemodialysis or peritoneal dialysis. Hyperkalemia was defined as serum potassium (sK+) ≥ 5 mEq/L based on the Pediatric Renal Nutrition Taskforce recommendations. We recorded age, dialysis vintage, urine output (24-h urine collection); dietary K+, energy, protein and sodium intake (three-day diaries); office blood pressure (BP) in children < 5 years and 24-h ABPM in older patients; biochemistry (creatinine, urea, sodium, bicarbonate, hemoglobin, phosphate, albumin) and antihypertensive drugs.

RESULTS

Forty-one patients were enrolled (10 peritoneal dialysis, 31 hemodialysis), median age 13.3 (IQR 10.6-15.8) years; 15 of them (36.6%) showed hyperkalemia, and median sK+ was 4.7 (4.4-5.0) mEq/L. Renin-angiotensin-aldosterone system inhibitors (RAASi) were prescribed in 9/15 patients with hyperkalemia (60%) and 7/26 (26.9%) without hyperkalemia (p = 0.04). Patients with hyperkalemia were older and had higher urea and creatinine than those with normal sK+. A backward stepwise multivariable model showed that the only predictors of hyperkalemia were age (b = 0.53, p = 0.01), urea (b = 0.02, p = 0.03) and treatment with RAASi (b = 2.75, p = 0.021).

CONCLUSIONS

While higher age, higher urea levels and treatment with RAASi independently predicted the occurrence of hyperkalemia, K+ intake was not associated with sK+ in children on dialysis. This emphasizes the importance of considering non-dietary causes of hyperkalemia and considering the bioavailability of K+ more than the total dietary K+ intake.

Endocrine and metabolic alterations in response to systemic inflammation and sepsis: a review article

Severe sepsis is cognate with life threatening multi-organ dysfunction. There is a disturbance in endocrine functions with alterations in several hormonal pathways. It has frequently been linked with dysfunction in the hypothalamic pituitary-adrenal axis (HPA). Increased cortisol or cortisolemia is evident throughout the acute phase, along with changes in the hypothalamic pituitary thyroid (HPT) axis, growth hormone-IGF-1 axis, insulin-glucose axis, leptin, catecholamines, renin angiotensin aldosterone axis, ghrelin, glucagon, hypothalamic pituitary gonadal (HGA) axis, and fibroblast growth factor-21. These changes and metabolic alterations constitute the overall response to infection in sepsis. Further research is essential to look into the hormonal changes that occur during sepsis, not only to understand their potential relevance in therapy but also because they may serve as prognostic indicators.

Updates in Chronic Kidney Disease

Chronic kidney disease (CKD) affects approximately 14% of adults in the United States and is present in at least 10% of the population worldwide. Blood glucose and blood pressure control are imperative to adequately manage CKD as they are the only primary prevention measures for the condition. Recent changes in CKD evaluation and medication therapies that modify disease progression and aid in managing complications such as anemia of CKD have emerged, including a newly approved mineralocorticoid receptor antagonist and hypoxia-inducible factor-prolyl hydroxylase inhibitor, respectively. This focused update on CKD evaluation and management will review the most recent evidence and approved agents to support patients with CKD, including a review of glomerular filtration rate measurement methods such as CKD-EPI 2021 and utilization of cystatin C, Kidney Disease Improving Global Outcomes (KDIGO) guidelines, American Diabetes Association (ADA) guidelines, and primary literature supporting the use of newer agents in CKD. Checklists for managing blood pressure and blood glucose, CKD-mineral bone disorder, and anemia of CKD targeted for pharmacists are also provided. Additionally, a discussion of Centers for Medicare & Medicaid (CMS) coverage of agents approved for managing complications of CKD is included.

Polysaccharides from Sacha Inchi shell reduces renal fibrosis in mice by modulating the TGF-β1/Smad pathway and intestinal microbiota

Renal fibrosis is a common pathway involved in the progression of various chronic kidney to end-stage diseases, posing a substantial global public health challenge in the search for effective and safe treatments. This study investigated the effects and mechanisms of sacha inchi shell polysaccharide (SISP) on renal fibrosis induced by a high-salt diet (HSD) in mice. By analysing kidney-related protein pathways and the structure of gut microbiota, we found that SISP significantly reduced urinary protein levels induced by a HSD from 41.08 to 22.95 μg/mL and increased urinary creatinine from 787.43 to 1294.50 μmol/L. It reduced renal interstitial collagen fibres by 11.30 %, thereby improving the kidney function. SISP lowered the mRNA expression of TGF-B1, fibronectin, α-SMA, Smad2/3, and TGFBRII, leading to decreased protein levels of TGF-β1, p-Smad2/3, p-TGFβRII, fibronectin, α-SMA, p-Smad2/3/Smad2/3, and p-TGFβRII/TGFβRII. These changes blocked downstream transcription in the TGF-β1/Smad signalling pathway, thereby attenuating renal fibrosis in HSD mice. In addition, SISP altered the intestinal flora imbalance in HSD mice by reducing the relative abundance of the genera, Akkermansia, Faecalibaculum, and unidentified_Ruminococcaceae, and reversing the decline in the levels of the genera, Lactobacillus and Bacteroides. In conclusion, SISP is a promising nutraceutical for renal fibrosis management.

Prognostic significance of preoperative nutritional status for heart transplantation patients

BACKGROUND

The association between malnutrition and outcomes of heart transplantation (HTx) has not been well studied. The purpose of this article was to evaluate the prognostic value of three different nutrition indices in HTx, including CONUT (Controlling Nutritional Status), NRI (Nutritional Risk Index) and GNRI (Geriatric Nutritional Risk Index).

METHODS

A total of 438 patients who underwent THx from January 2015 to December 2020 were included in this study. The nutritional status of the patients was evaluated by CONUT, NRI and GNRI. Kaplan-Meier (KM) curves were constructed to compare the difference in overall survival (OS) between the normal and malnutrition groups in each index. Cox regression analysis was used to identify the independent risk factors of OS. The predictive power was compared by time-dependent ROC and time-dependent ccurves. Logistic regression model was used to evaluate the relationship between these three nutrition indices and postoperative clinical events.

RESULTS

336 (76.7%), 183 (43.8%), and 190 (43.4%) patients had malnutrition according to CONUT, NRI and GNRI calculations. 102 (23.3%) patients had died at the end of follow-up. After adjustment for confounding variables, multivariate Cox analysis showed that CONUT [HR 1.286 (95%CI 1.166 ~ 1.419); p < 0.001], NRI [HR 0.942 (95%CI 0.923 ~ 0.962); p < 0.001] and GNRI [HR 0.959 (95%CI 0.939 ~ 0.979); p < 0.001] were all independent predictors for OS. The predictive power of CONUT score was higher than that of NRI (p = 0.045) and GNRI (p < 0.001). Regarding the postoperative complications, multivariate logistic regression model showed that malnutrition assessed by CONUT [HR 1.156 (95%CI 1.032 ~ 1.294); p = 0.012] and NRI [HR 1.543 (95%CI 1.008 ~ 2.362); p = 0.046] was independent risk factors for posttransplant infections.

CONCLUSION

Poor nutritional status, as assessed by CONUT, NRI and GNRI, was associated with an increased risk of mortality after HTx. CONUT displayed the highest predictive power compared to the other two indices. CONUT and NRI were also independently associated with posttransplant infections.

Quantification of endogenous Angiotensin 1-10, 1-9, 1-8, 1-7, and 1-5 in human plasma using micro-UHPLC-MS/MS: Outlining the importance of the pre-analytics for reliable results

Angiotensin peptides (ANGs) play a central role in the renin-angiotensin-aldosterone system, rendering them interesting biomarkers associated with hypertension. Precise quantification of circulating ANGs holds the potential to assess the activity of angiotensin-converting enzyme (ACE), a key protease targeted by widely prescribed drugs, namely ACE inhibitors. This ability could pave the way for personalised medicine, offering insights into the prescription of inhibitors targeting either the proteases or the receptors within the system. Despite recent developments in liquid chromatography-mass spectrometry (LC-MS) methods for measuring circulating ANG concentrations, comprehensive stability studies of ANGs in human plasma are absent in the literature, raising concerns about the reliability of measured concentrations and their link to clinical conditions. To address this critical gap, we conducted an exhaustive evaluation of the pre-analytical stability of ANG1-10, ANG1-9, ANG1-8, ANG1-7, and ANG1-5. By employing surfactants to mitigate non-specific adsorption and a dedicated mix of protease inhibitors to limit protease activity, we established an MS-based assay for these five peptides. We used this method to quantify circulating concentrations of ANGs in the plasma of 11 healthy donors and 3 patients under kidney dialysis. Our findings revealed that ANG1-10 and ANG1-8 circulate at concentrations ranging from 1 to 10 pM in healthy subjects and exhibit a high degree of correlation. Notably, ANG1-9, ANG1-7, and ANG1-5 were undetectable in any of the 14 patients, despite a sub-picomolar limit of detection. This strikingly contrasts with the reference concentrations reported in the literature, which typically fall within the picomolar range. In light of these discrepancies, we strongly advocate for rigorous pre-analytical considerations and comprehensive stability studies to ensure reliable results. We emphasise the pivotal role of heightened pre-analytical awareness within the clinical chemistry community, and we hope for continued growth in this critical area.

Results from a Phase 1 Study Assessing the Pharmacokinetics of the Aldosterone Synthase Inhibitor Baxdrostat in Participants with Varying Degrees of Renal Function

Baxdrostat is a selective small-molecule aldosterone synthase inhibitor in development for treatment of hypertension and chronic kidney disease. This phase 1, open-label, parallel-group study assessed the safety and pharmacokinetics (PK) of baxdrostat in participants with varying degrees of renal function. Participants were enrolled into control (estimated glomerular filtration rate [eGFR] ≥60 mL/min), moderate to severe renal impairment (eGFR 15-59 mL/min), or kidney failure (eGFR <15 mL/min) groups and received a single 10-mg baxdrostat dose followed by 7 days of inpatient PK blood and urine sampling. Safety was assessed by adverse events, clinical laboratory evaluations, vital signs, physical examinations, and electrocardiograms (ECGs). Thirty-2 participants completed the study. There were no deaths and only 1 mild drug-related adverse event (diarrhea). No clinically meaningful changes in laboratory values, vital signs, physical examinations, or ECGs occurred. Plasma concentration-time curves of baxdrostat were similar among all groups. Urine PK parameters were similar (approximately 12% excreted) in the moderate to severe renal impairment and control groups. Inadequate urine production in the kidney failure group resulted in minimal urinary baxdrostat excretion. Renal impairment had no significant impact on systemic exposure or clearance of baxdrostat, suggesting that dose adjustment due to PK differences in patients with kidney disease is unnecessary.

Letter: Impact of antiviral treatment on renal function in patients with chronic hepatitis B

This article is linked to Hong et al papers. To view these articles, visit https://doi.org/10.1111/apt.17819 and https://doi.org/10.1111/apt.17937

The role of a novel mineralocorticoid receptor antagonist, finerenone, in chronic kidney disease: mechanisms and clinical advances

BACKGROUND

Chronic kidney disease (CKD) poses a significant health risk in contemporary society. Current CKD treatments primarily involve renin-angiotensin-aldosterone system inhibitors and mineralocorticoid receptor antagonists, albeit associated with hyperkalemia risks. A novel selective mineralocorticoid receptor antagonist, finerenone, offers a promising, safer alternative for CKD therapy. This review comprehensively assesses the role and efficacy of finerenone in CKD treatment by analyzing clinical and animal studies. Emerging evidence consistently supports finerenone's ability to effectively slow the progression of CKD. By targeting the mineralocorticoid receptor, finerenone not only mitigates renal damage but also exhibits a favorable safety profile, minimizing hyperkalemia concerns.

CONCLUSION

Finerenone emerges as a valuable addition to CKD therapy, demonstrating potential benefits in delaying CKD progression while minimizing side effects. Nevertheless, further clinical trials are necessary to provide a comprehensive understanding of its safety and efficacy.

Potential therapeutic medicines for renal fibrosis: Small-molecule compounds and natural products

Renal fibrosis is the pathological change process of chronic kidney disease deteriorating continuously. When the renal organ is stimulated by external stimuli, it will trigger the damage and phenotypic changes of some intrinsic cells in the kidney. When the body's autoimmune regulation or external treatment is not prompted enough to restore the organ, the pathological process is gradually aggravating, inducing a large amount of intracellular collagen deposition, which leads to the appearance of fibrosis and scarring. The renal parenchyma (including glomeruli and tubules) begins to harden, making it difficult to repair the kidney lesions. In the process of gradual changes in the kidney tissue, the kidney units are severely damaged and the kidney function shows a progressive decline, eventually resulting in the clinical manifestation of end-stage renal failure, namely uremia. This review provides a brief description of the diagnosis, pathogenesis, and potential therapeutic inhibitors of renal fibrosis. Since renal fibrosis has not yet had a clear therapeutic target and related drugs, some potential targets and relevant inhibitors are discussed, especially pharmacological effects and interactions with targets. Some existing natural products have potential efficacy for renal fibrosis, which is also roughly summarized, hoping that this article would have reference significance for the treatment of renal fibrosis.

Common mechanisms underlying diabetic vascular complications: focus on the interaction of metabolic disorders, immuno-inflammation, and endothelial dysfunction

Diabetic vascular complications (DVCs), including macro- and micro- angiopathy, account for a high percentage of mortality in patients with diabetes mellitus (DM). Endothelial dysfunction is the initial and role step for the pathogenesis of DVCs. Hyperglycemia and lipid metabolism disorders contribute to endothelial dysfunction via direct injury of metabolism products, crosstalk between immunity and inflammation, as well as related interaction network. Although physiological and phenotypic differences support their specified changes in different targeted organs, there are still several common mechanisms underlying DVCs. Also, inhibitors of these common mechanisms may decrease the incidence of DVCs effectively. Thus, this review may provide new insights into the possible measures for the secondary prevention of DM. And we discussed the current limitations of those present preventive measures in DVCs research. Video Abstract.

Prevalence of Chronic Kidney Disease Among US Adults With Hypertension, 1999 to 2018

BACKGROUND

Hypertension is a major cause of end-stage renal disease. Assessing temporal trends in the prevalence of chronic kidney disease (CKD) in hypertension could provide information for public health policies and plans.

METHODS

From the National Health and Nutrition Examination Survey from 1999 to 2018, a probability sample of adults aged ≥20 years was collected. The primary outcomes were classified according to the estimated glomerular filtration rate and urinary albumin. Trend tests were performed to assess age-standardized prevalence trends of CKD, albuminuria, and macroalbuminuria in US adults with hypertension.

RESULTS

A total of 23 120 US adults with hypertension were included in this study. The prevalence of any CKD, albuminuria, or macroalbuminuria in hypertension remained relatively stable. However, the age-standardized prevalence of stage 1 CKD in hypertension increased from 4.9% in 2003 to 2006 to 7.0% in 2015 to 2018 (P=0.0077 for trend). The age-standardized prevalence of stage 3b CKD in hypertension decreased from 2.9% in 2011 to 2014 to 2.1% in 2015 to 2018 (P=0.0350 for trend). A similar trend was observed for the age-standardized prevalence of stages 3 to 5 CKD in hypertension, which declined from 10.9% in 2011 to 2014 to 8.9% in 2015 to 2018 (P=0.0160 for trend).

CONCLUSIONS

Among US adults with hypertension, the prevalence of any CKD, albuminuria, and macroalbuminuria remained relatively stable from 1999 to 2018, whereas the hypertensive population showed an increasing trend in stage 1 CKD from 2003 to 2006 to 2015 to 2018 and a decreasing trend in the prevalence of stages 3 to 5 and 3b CKD from 2011 to 2014 to 2015 to 2018.

Trends in renal function in Northern Sweden 1986-2014: data from the seven cross-sectional surveys within the Northern Sweden MONICA study

OBJECTIVE

The prevalence of chronic kidney disease (CKD) is increasing globally, and CKD is closely related to cardiovascular disease (CVD). CKD and CVD share several risk factors (RF), such as diabetes, hypertension, obesity and smoking, and the prevalence of these RF has changed during the last decades, and we aimed to study the effect on renal function over time.

DESIGN

Repeated cross-sectional population-based studies.

SETTING

The two Northern counties (Norr- and Västerbotten) in Sweden.

PARTICIPANTS

Within the MONitoring Trends and Determinants of CArdiovascular Disease (MONICA) study, seven surveys were performed between 1986 and 2014, including participants aged 25-64 years (n=10 185).

INTERVENTIONS

None.

MEASURES

Information on anthropometry, blood pressure and cardiovascular risk factors was collected. Creatinine and cystatin C were analysed in stored blood samples and the estimated glomerular filtration rate (eGFR) calculated using the creatinine-based Lund-Malmö revised and Chronic Kidney Disease Epidemiology Collaboration (eGFRcrea) equations as well as the cystatin C-based Caucasian, Asian, Paediatric and Adult cohort (CAPA) equation (eGFRcysC). Renal function over time was analysed using univariable and multivariable linear regression models.

RESULTS

Renal function, both eGFRcrea and eGFRcysC, decreased over time (both p<0.001) and differed between counties and sexes. In a multivariable analysis, study year remained inversely associated with both eGFRcrea and eGFRcysC (both p<0.001) after adjustment for classical cardiovascular RF.

CONCLUSION

Renal function has deteriorated in Northern Sweden between 1986 and 2014.

Crataeva nurvala Bark (Capparidaceae) Extract Modulates Oxidative Stress-Related Gene Expression, Restores Antioxidant Enzymes, and Prevents Oxidative Stress in the Kidney and Heart of 2K1C Rats

Objective

Crataeva nurvala is a medicinal plant, which contains a wide range of polyphenolic and bioactive compounds. The aim of the study was to evaluate the renal-protective activity of Crataeva nurvala in two-kidney, one-clip (2K1C) rats.

Methods

In this study, the ethanol extract of Crataeva nurvala bark at a dose of 100 mg/kg was orally used to treat 2K1C rats for four weeks. At the end of the experiment, all rats were sacrificed and tissue samples were collected for further biochemical and histological assessments.

Results

This investigation showed that Crataeva nurvala treatment prevented the kidney dysfunction in 2K1C rats. Uric acid and creatinine concentration and CK-MB activities increased in 2K1C rats which were normalized by Crataeva nurvala. 2K1C rats also showed increased oxidative stress, depicted by the elevated level of MDA, NO, and APOP in plasma and tissues. Oxidative stress parameters declined in 2K1C rats by the treatment of Crataeva nurvala. These results could be attributed to the restoration of antioxidant enzyme activities such as catalase and SOD. Crataeva nurvala extracts also upregulated antioxidant gene expression in the kidneys of 2K1C rats. Moreover, several anti-inflammatory genes were suppressed by Crataeva nurvala treatment in 2K1C rats. Furthermore, fibrosis and collagen deposition in the kidneys were also lowered by the treatment of the Crataeva nurvala extract.

Conclusion

The experimental data suggest that the Crataeva nurvala extract protected renal damage and oxidative stress, probably by restoring antioxidant enzymes activities in 2K1C rats.

Clustering-based spatial analysis (CluSA) framework through graph neural network for chronic kidney disease prediction using histopathology images

Machine learning applied to digital pathology has been increasingly used to assess kidney function and diagnose the underlying cause of chronic kidney disease (CKD). We developed a novel computational framework, clustering-based spatial analysis (CluSA), that leverages unsupervised learning to learn spatial relationships between local visual patterns in kidney tissue. This framework minimizes the need for time-consuming and impractical expert annotations. 107,471 histopathology images obtained from 172 biopsy cores were used in the clustering and in the deep learning model. To incorporate spatial information over the clustered image patterns on the biopsy sample, we spatially encoded clustered patterns with colors and performed spatial analysis through graph neural network. A random forest classifier with various groups of features were used to predict CKD. For predicting eGFR at the biopsy, we achieved a sensitivity of 0.97, specificity of 0.90, and accuracy of 0.95. AUC was 0.96. For predicting eGFR changes in one-year, we achieved a sensitivity of 0.83, specificity of 0.85, and accuracy of 0.84. AUC was 0.85. This study presents the first spatial analysis based on unsupervised machine learning algorithms. Without expert annotation, CluSA framework can not only accurately classify and predict the degree of kidney function at the biopsy and in one year, but also identify novel predictors of kidney function and renal prognosis.

Role of the Renin Angiotensin Aldosterone System in the Pathogenesis of Sepsis-Induced Acute Kidney Injury: A Systematic Review

BACKGROUND

Sepsis is a life-threatening condition responsible for up to 20% of all global deaths. Kidneys are among the most common organs implicated, yet the pathogenesis of sepsis-induced acute kidney injury (S-AKI) is not completely understood, resulting in the treatment being nonspecific and responsive. In situations of stress, the renin angiotensin aldosterone system (RAAS) may play a role. This systematic review focuses on analyzing the impact of the RAAS on the development of S-AKI and discussing the use of RAAS antagonists as an emerging therapeutic option to minimize complications of sepsis.

METHODS

Studies were identified using electronic databases (Medline via PubMed, Google Scholar) published within the past decade, comprised from 2014 to 2023. The search strategy was conducted using the following keywords: sepsis, S-AKI, RAAS, Angiotensin II, and RAAS inhibitors. Studies on human and animal subjects were included if relevant to the keywords.

RESULTS

Our search identified 22 eligible references pertaining to the inclusion criteria. Treatment of sepsis with RAAS inhibitor medications is observed to decrease rates of S-AKI, reduce the severity of S-AKI, and offer an improved prognosis for septic patients.

CONCLUSION

The use of RAAS antagonists as a treatment after the onset of sepsis has promising findings, with evidence of decreased renal tissue damage and rates of S-AKI and improved survival outcomes.

REGISTRATION

INPLASY202360098.

Research Progress of Cordyceps sinensis and Its Fermented Mycelium Products on Ameliorating Renal Fibrosis by Reducing Epithelial-to-Mesenchymal Transition

Renal fibrosis is a hallmark and common outcome of various chronic kidney diseases (CKDs) and manifests pathologically as accumulation and deposition of extracellular matrix (ECM) in the kidney. Epithelial-to-mesenchymal transition (EMT) has been shown to be an important mechanism involved in renal fibrosis. Cordyceps sinensis, a traditional Chinese medicine, has long been used for the treatment of renal fibrosis. As research on the mycelium of C. sinensis progressed, a variety of medicines developed from fermented mycelium were used to treat CKD. However, their efficacies and mechanisms have not been fully summarized. In this review, five medicines developed from fermented mycelium of C. sinensis are presented. The pharmacodynamic effects of C. sinensis on different animal models of renal fibrosis are summarized. The in vitro studies and related mechanisms of C. sinensis on renal cells are detailed. Finally, the application and efficacy of these five commercial medicines that meet national standards in different types of CKD are summarized. From this review, it can be concluded that C. sinensis can alleviate various causes of renal fibrosis to some extent, and its mechanism is related to TGF-β1 dependent signaling, inhibition of inflammation, and improvement of renal function. Further research on rigorously designed, large-sample, clinically randomized controlled trial studies and detailed mechanisms should be conducted.

Understanding and Treatment Strategies of Hypertension and Hyperkalemia in Chronic Kidney Disease

Hypertension and potassium imbalance are commonly observed in chronic kidney disease (CKD) patients. The development of hypertension would be related to several mechanisms. Hypertension is related to body mass index, dietary salt intake, and volume overload and is treated with antihypertensives. In CKD patients, managing hypertension can provide important effects that can slow the progression of CKD or reduce complications associated with reduced glomerular filtration rate. The prevalence of hyperkalemia and hypokalemia in CKD patients was similar at 15-20% and 15-18%, respectively, but more attention needs to be paid to treating and preventing hyperkalemia, which is related to a higher mortality rate, than hypokalemia. Hyperkalemia is prevalent in CKD due to impaired potassium excretion. Serum potassium level is affected by renin-angiotensin-aldosterone system inhibitors and diuretics and dietary potassium intake and can be managed by potassium restriction dietary, optimized renin-angiotensin-aldosterone system inhibitor, sodium polystyrene sulfonate, patiromer, and hemodialysis. This review discussed strategies to mitigate and care for the risk of hypertension and hyperkalemia in CKD patients.

[Renal pathophysiology and pharmacological mechanisms of nephroprotection]

Several risk factors may affect the progression of chronic kidney disease (CKD). Arterial hypertension, proteinuria, obesity, intraglomerular hypertension, smoking and metabolic control in diabetes mellitus are the main modifiable risk factors for progression. The progression of CKD involves many cellular processes that originate in specific compartments of the kidney, the vascular compartment with nephroangiosclerosis and the tubulointerstitial compartment with fibrosis and tubulointerstitial atrophy, and there may be overlap between both mechanisms. Given the involvement of so many risk factors and so many pathogenic pathways in the progression of CKD, the best hope for delaying or preventing the progression of CKD lies in a combined and multidisciplinary therapeutic approach, based on the existing evidence and acting on all these processes and pathways from the mechanistic point of view, and on a global process that is cardiovascular and renal risk to improve the prognosis of patients.

Therapeutic potential of a novel peripherally restricted CB1R inverse agonist on the progression of diabetic nephropathy

Objective

This study assessed the efficacy of INV-202, a novel peripherally restricted cannabinoid type-1 receptor (CB1R) inverse agonist, in a streptozotocin-induced type-1 diabetes nephropathy mouse model.

Methods

Diabetes was induced in 8-week-old C57BL6/J male mice via intraperitoneal injection of streptozotocin (45 mg/kg/day for 5 days); nondiabetic controls received citrate buffer. Diabetic mice were randomized to 3 groups based on blood glucose, polyuria, and albuminuria, and administered daily oral doses for 28-days of INV-202 at 0.3 or 3 mg/kg or vehicle.

Results

INV-202 did not affect body weight but decreased kidney weight compared with the vehicle group. While polyuria was unaffected by INV-202 treatment, urinary urea (control 30.77 ± 14.93; vehicle 189.81 ± 31.49; INV-202 (0.3 mg/kg) 127.76 ± 20; INV-202 (3 mg/kg) 93.70 ± 24.97 mg/24h) and albumin (control 3.06 ± 0.38; vehicle 850.08 ± 170.50; INV-202 (0.3 mg/kg) 290.65 ± 88.70; INV-202 (3 mg/kg) 111.29 ± 33.47 µg/24h) excretion both decreased compared with vehicle-treated diabetic mice. Compared with the vehicle group, there was a significant improvement in the urinary albumin to creatinine ratio across INV-202 groups. Regardless of the dose, INV-202 significantly reduced angiotensin II excretion in diabetic mice. The treatment also decreased Agtr1a renal expression in a dose-dependent manner. Compared with nondiabetic controls, the glomerular filtration rate was increased in the vehicle group and significantly decreased by INV-202 at 3 mg/kg. While the vehicle group showed a significant loss in the mean number of podocytes per glomerulus, INV-202 treatment limited podocyte loss in a dose-dependent manner. Moreover, in both INV-202 groups, expression of genes coding for podocyte structural proteins nephrin (Nphs1), podocin (Nphs2), and podocalyxin (Pdxl) were restored to levels similar to nondiabetic controls. INV-202 partially limited the proximal tubular epithelial cell (PTEC) hyperplasia and normalized genetic markers for PTEC lesions. INV-202 also reduced expression of genes contributing to oxidative stress (Nox2, Nox4, and P47phox) and inflammation (Tnf). In addition, diabetes-induced renal fibrosis was significantly reduced by INV-202.

Conclusions

INV-202 reduced glomerular injury, preserved podocyte structure and function, reduced injury to PTECs, and ultimately reduced renal fibrosis in a streptozotocin-induced diabetic nephropathy mouse model. These results suggest that INV-202 may represent a new therapeutic option in the treatment of diabetic kidney disease.

Levistolide A ameliorates fibrosis in chronic kidney disease via modulating multitarget actions in vitro and in vivo

AIMS

The increasing incidence of chronic kidney disease (CKD) urgently calls for effective nephroprotective agents. Traditional Chinese Medicine Angelica sinensis and its formula are well known for CKD therapy, but the underlying mechanisms and effective substances of reno-protective effects remain unclear. To this end, we isolated eleven ligustilide dimers (1-11) from A. sinensis and examined the molecular mechanism of their nephroprotective effects.

MAIN METHODS

Because of internal RAS playing an important role in CKD, we used renin expression as a target and screened preliminarily for antifibrotic effects of ligustilide dimers (1-11) by constructing a dual luciferase reporter gene in vitro. Furthermore, the reno-protective effects of the ligustilides and their underlying mechanism were investigated in TGF-β1-stimulated HK-2 cells and 5/6 nephrectomy (Nx) mice.

KEY FINDINGS

The ligustilide dimers exhibited anti-fibrotic effects by inhibiting human renin (hREN) promoter activity to decrease renin expression and down-regulate the expression of fibrosis-related factors, including α-SMA, collagen I, and fibronectin in vitro. Levistolide A (LA) and angeolide keto ester (AK) were screened out to identify their ability and underlying mechanism for treating CKD. Experimental validation further indicated that LA or AK treatment inhibited the expression of key molecules in RAS, TGF-β1/Smad, and MAPK pathways to downregulate ECM deposition. Furthermore, LA obviously meliorated renal injury in 5/6 Nx mice through ameliorating oxidant stress, inflammation, apoptosis and renal fibrosis.

SIGNIFICANCE

The experimental results demonstrated that ligustilide dimers were potential nephroprotective agents. LA might be an attractive drug candidate for renin-targeted CKD therapy.

Nephrotic Syndrome and Renin-angiotensin System: Pathophysiological Role and Therapeutic Potential

Idiopathic Nephrotic Syndrome (INS) is the most frequent etiology of glomerulopathy in pediatric patients and one of the most common causes of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in this population. In this review, we aimed to summarize evidence on the pathophysiological role and therapeutic potential of the Renin-Angiotensin System (RAS) molecules for the control of proteinuria and for delaying the onset of CKD in patients with INS. This is a narrative review in which the databases PubMed, Web of Science, and Sci- ELO were searched for articles about INS and RAS. We selected articles that evaluated the pathophysiological role of RAS and the effects of the alternative RAS axis as a potential therapy for INS. Several studies using rodent models of nephropathies showed that the treatment with activators of the Angiotensin-Converting Enzyme 2 (ACE2) and with Mas receptor agonists reduces proteinuria and improves kidney tissue damage. Another recent paper showed that the reduction of urinary ACE2 levels in children with INS correlates with proteinuria and higher concentrations of inflammatory cytokines, although data with pediatric patients are still limited. The molecules of the alternative RAS axis comprise a wide spectrum, not yet fully explored, of potential pharmacological targets for kidney diseases. The effects of ACE2 activators and receptor Mas agonists show promising results that can be useful for nephropathies including INS.

Eplerenone inhibits the macrophage-to-myofibroblast transition in rats with UUO-induced type 4 cardiorenal syndrome through the MR/CTGF pathway

Cardiovascular complications are the leading causes of death in patients with chronic kidney disease (CKD), accounting for approximately 50% of deaths. Despite significant advances in the understanding of cardiac disease due to CKD, the underlying mechanisms involved in many pathological changes have not been fully elucidated. In our previous study, we observed severe fibrosis in the contralateral kidney of a 6-month-old rat UUO model. In the present experiment, we also observed severe fibrosis in the hearts of rats subjected to UUO and the macrophage-to-myofibroblast transition (MMT). These effects were inhibited by the mineralocorticoid receptor (MR) blocker eplerenone. Notably, in vitro, aldosterone-activated MR induced the MMT and subsequently promoted the secretion of CTGF, the target of MR, from macrophages; these changes were inhibited by eplerenone. The CTGF also induced the MMT and both the aldosterone and CTGF-induced MMT could be alleviated by the CTGF blocker. In conclusion, our results suggest that targeting the MR/CTGF pathway to inhibit the MMT may be an effective therapeutic strategy for the treatment of cardiac fibrosis.

Canagliflozin reverses Th1/Th2 imbalance and promotes podocyte autophagy in rats with membranous nephropathy

Idiopathic membranous nephropathy is the main cause of chronic kidney disease (CKD). Studies have shown sodium-glucose co-transporter 2 (SGLT2) inhibitors significantly delay renal outcomes in patients with CKD, but the exact mechanism remains unknown. In this study, we investigated the mechanism by which the SGLT2 inhibitor canagliflozin attenuates podocyte injury by reversing the imbalance in Helper T cell 1 (Th1)/Helper T cell 2 (Th2) in peripheral blood of rats with membranous nephropathy (MN). MN rats were gavaged with canagliflozin (10 mg/kg/d) and losartan (10 mg/kg/d), respectively, for eight weeks. Compared with the MN group, the urinary ratio of total protein and the creatinine levels of the canagliflozin group decreased significantly. Canagliflozin improved the glomerulus pathological damage, increased the expression levels of podocyte marker proteins. The protective effect of canagliflozin on kidneys was more obvious than that of losartan. Treatment with canagliflozin increased the proportion of Th1 cells by 2.3 times, decreased the proportion of Th2 cells by 68.5%, and significantly restrained the synthesis of immunoglobulin G1 in B-cells and glomerulus subepithelial immune complex deposition. Co-culture of B-cells derived from MN rats with podocytes triggered the activation of phosphorylation of mTOR and ULK1 of podocytes, inhibited podocyte autophagy and resulted in podocyte injury. B-cells derived from canagliflozin treatment rats reversed these effects above. In conclusion, canagliflozin exerts a protective effect on kidneys by reversing the imbalance in Th1/Th2 cells in MN rats and restoring the autophagy of podocytes inhibited by the abnormal immunoglobulin G secretion from B-cells.

Kidney-Targeted Drug Delivery System Based on Metformin-Grafted Chitosan for Renal Fibrosis Therapy

Our previous study demonstrated that metformin plays an anti-fibrotic role in addition to its hypoglycemic effect. Worryingly, it often requires more than 5 times the hypoglycemic dose to achieve a satisfactory anti-fibrotic effect, which greatly increases the risk of systemic acidosis caused by metformin overdose. Low-molecular-weight chitosan (LMWC) has natural kidney-targeting properties and good biocompatibility and degradability. Thus, we synthesized a novel carrier metformin-grafted chitosan (CS-MET) based on an imine reaction between oxidized chitosan and metformin. Then, GFP was recruited to form GFP-loaded CS-MET nanoparticles (CS-MET/GFP NPs) with controllable particle size. We hypothesized that CS-MET/GFP NPs would enrich in the kidney and be absorbed by HK-2 cells via megalin-mediated endocytosis by intravenous injection, which may avoid systemic acidosis caused by metformin overdose. Subsequently, the nanoparticle ruptures and releases metformin to exert its anti-apoptotic, anti-inflammatory, and anti-fibrotic effects. Our results showed that CS-MET/GFP NPs have great transfection efficiency and could enter HK-2 cells mainly through megalin-mediated endocytosis. Compared to the free metformin, CS-MET/GFP NPs showed similar anti-apoptotic ability but better therapeutic effects on cellular inflammation and fibrosis in vitro. On the other hand, CS-MET/GFP NPs showed great kidney-targeting ability and superior anti-apoptotic, anti-inflammatory, and anti-fibrotic effects in vivo.

Crosstalk between kidney and liver in non-alcoholic fatty liver disease: mechanisms and therapeutic approaches

Liver and kidney are vital organs that maintain homeostasis and injury to either of them triggers pathogenic pathways affecting the other. For example, non-alcoholic fatty liver disease (NAFLD) promotes the progression of chronic kidney disease (CKD), vice versa acute kidney injury (AKI) endorses the induction and progression of liver dysfunction. Progress in clinical and basic research suggest a role of excessive fructose intake, insulin resistance, inflammatory cytokines production, activation of the renin-angiotensin system, redox imbalance, and their impact on epigenetic regulation of gene expression in this context. Recent developments in experimental and clinical research have identified several biochemical and molecular pathways for AKI-liver interaction, including altered liver enzymes profile, metabolic acidosis, oxidative stress, activation of inflammatory and regulated cell death pathways. This review focuses on the current preclinical and clinical findings on kidney-liver crosstalk in NAFLD-CKD and AKI-liver dysfunction settings and highlights potential molecular mechanisms and therapeutic targets.

Improving Postoperative Acute Kidney Injury Rates Following Primary Total Joint Arthroplasty

BACKGROUND

Perioperative hip and knee arthroplasty complications remain a significant clinical and financial burden. Our institution has shifted to developing protocols to decrease these perioperative complications. This study focuses on acute kidney injury (AKI) rate status post primary total joint arthroplasty (TJA). Current literature demonstrates a 2%-15% incidence of AKI following TJA. However, there is a paucity of published literature on protocols that have effectively reduced AKI rates following TJA. The purpose of this study is to evaluate the effect that our institutionally developed perioperative renal protocol had on the postoperative AKI rates.

METHODS

A retrospective cohort study was performed. Patient demographics, baseline creatinine, and postoperative creatinine values during the patient's hospitalization were collected and analyzed. The preintervention cohort data contained all patients at our institution who underwent a primary TJA from November 1, 2016 to January 1, 2018. The postintervention cohort included all primary TJA patients from July 1, 2018 to February 2, 2020. AKI was defined using the AKI Network classification system comparing baseline and postoperative creatinine values. A multivariate analysis was performed to determine the statistical significance of our results.

RESULTS

Before intervention 1013 patients underwent a primary TJA with 68 patients developing an AKI postoperatively. After intervention 2169 patients underwent primary TJA with 90 patients developing an AKI (6.71% vs 4.15%; P = .0015, odds ratio = 0.59, 95% confidence interval = 0.42-0.82).

CONCLUSION

This study demonstrated that implementation of a perioperative renal protocol can significantly reduce AKI rates. A reduction in AKI rates following TJA will result in improved outcomes and secondarily decrease the financial impact of postoperative complications seen following TJA.

Microbiome in Chronic Kidney Disease (CKD): An Omics Perspective

Chronic kidney disease (CKD) is predominant in 10% of the world’s adult population, and is increasingly considered a silent epidemic. Gut microbiota plays an essential role in maintaining host energy homeostasis and gut epithelial integrity. Alterations in gut microbiota composition, functions and, specifically, production of metabolites causing uremic toxicity are often associated with CKD onset and progression. Here, we present the latest omics (transcriptomics, proteomics and metabolomics) studies that explore the connection between CKD and gut microbiome. A review of the available literature using PubMed was performed using the keywords “microb*”, “kidney”, “proteom”, “metabolom” and “transcript” for the last 10 years, yielding a total of 155 publications. Following selection of the relevant studies (focusing on microbiome in CKD), a predominance of metabolomics (n = 12) over transcriptomics (n = 1) and proteomics (n = 6) analyses was observed. A consensus arises supporting the idea that the uremic toxins produced in the gut cause oxidative stress, inflammation and fibrosis in the kidney leading to CKD. Collectively, findings include an observed enrichment of Eggerthella lenta, Enterobacteriaceae and Clostridium spp., and a depletion in Bacteroides eggerthii, Roseburia faecis and Prevotella spp. occurring in CKD models. Bacterial species involved in butyrate production, indole synthesis and mucin degradation were also related to CKD. Consequently, strong links between CKD and gut microbial dysbiosis suggest potential therapeutic strategies to prevent CKD progression and portray the gut as a promising therapeutic target.

ACE2: a key modulator of the renin-angiotensin system and pregnancy

Angiotensin-converting enzyme 2 (ACE2) is a membrane-bound protein containing 805 amino acids. ACE2 shows approximately 42% sequence similarity to somatic ACE but has different biochemical activities. The key role of ACE2 is to catalyze the vasoconstrictor peptide angiotensin (ANG) II to Ang-(1–7), thus regulating the two major counterbalancing pathways of the renin-angiotensin system (RAS). In this way, ACE2 plays a protective role in end-organ damage by protecting tissues from the proinflammatory actions of ANG II. The circulating RAS is activated in normal pregnancy and is essential for maintaining fluid and electrolyte homeostasis and blood pressure. Renin-angiotensin systems are also found in the conceptus. In this review, we summarize the current knowledge on the regulation and function of circulating and uteroplacental ACE2 in uncomplicated and complicated pregnancies, including those affected by preeclampsia and fetal growth restriction. Since ACE2 is the receptor for SARS-CoV-2, and COVID-19 in pregnancy is associated with more severe disease and increased risk of abnormal pregnancy outcomes, we also discuss the role of ACE2 in mediating some of these adverse consequences. We propose that dysregulation of ACE2 plays a critical role in the development of preeclampsia, fetal growth restriction, and COVID-19-associated pregnancy pathologies and suggest that human recombinant soluble ACE2 could be a novel therapeutic to treat and/or prevent these pregnancy complications.

Renin Angiotensin Aldosterone System Inhibitors in Chronic Kidney Disease: A Difficult Equation

Chronic kidney disease (CKD) is a global health problem and is strongly associated with hypertension (HTN) and impaired quality of life. Managing HTN with agents that block the renin angiotensin aldosterone system (RAAS) remains the gold standard, however there is a misleading impression that patients with impaired renal function or those receiving hemodialysis should not be treated with RAAS inhibitors. To date, only a few data in this field are available, given that this population subset is systematically excluded from many major clinical trials. The purpose of this review was to solve the difficult equation regarding the optimal use of RAAS blockade in patients with CKD.

Effect of a sodium restriction diet on albuminuria and blood pressure in diabetic kidney disease patients: a meta-analysis

BACKGROUND

A sodium restriction diet is a key component of chronic kidney disease (CKD) management. However, the efficacy of its use in patients with diabetic kidney disease (DKD) is uncertain. The present meta-analysis explored the effects of restricting sodium intake on albuminuria and blood pressure in DKD patients with albuminuria.

METHODS

We searched the Cochrane Central Register of Controlled Trials, Web of Science, MEDLINE, and EMBASE for randomized controlled trials, and we reviewed the references of all searched articles to avoid omitting other relevant articles. Our primary endpoints were blood pressure, albumin excretion rate, and plasma renin activity. We assessed pooled data using a random-effects model.

RESULTS

Of the 661 articles identified, a total of 12 articles were included in the meta-analysis. The random-effects model indicated that salt-restriction diet interventions led to a poled - 4.72 mmHg (95% CI - 6.71, - 2.73) difference in systolic blood pressure and that the intervention resulted in a 2.33 mmHg lower diastolic blood pressure (95% CI - 3.61, - 1.05). In patients with microalbuminuria, restricted sodium intake decreased the albumin excretion rate (AER) by 12.62 mg/min (95% CI - 19.64, - 5.60). Furthermore, the AER was 127.69 mg/min lower in patients with macroalbuminuria (95% CI - 189.07, - 66.32).

CONCLUSION

Moderate sodium restriction diets reduce urinary albumin excretion and decrease the level of blood pressure, especially for patients with macro-albuminuria. Thus, it is necessary to strengthen the intervention and health education as well as to provide individualized dietary advice.

Molecular Basis, Diagnostic Challenges and Therapeutic Approaches of Alport Syndrome: A Primer for Clinicians

Alport syndrome is a genetic and hereditary disease, caused by mutations in the type IV collagen genes COL4A3, COL4A4 and COL4A5, that affects the glomerular basement membrane of the kidney. It is a rare disease with an underestimated prevalence. Genetic analysis of population cohorts has revealed that it is the second most common inherited kidney disease after polycystic kidney disease. Renal involvement is the main manifestation, although it may have associated extrarenal manifestations such as hearing loss or ocular problems. The degree of expression of the disease changes according to the gene affected and other factors, known or yet to be known. The pathophysiology is not yet fully understood, although some receptors, pathways or molecules are known to be linked to the disease. There is also no specific treatment for Alport syndrome; the most commonly used are renin–angiotensin–aldosterone system inhibitors. In recent years, diagnosis has come a long way, thanks to advances in DNA sequencing technologies such as next-generation sequencing (NGS). Further research at the genetic and molecular levels in the future will complete the partial vision of the pathophysiological mechanism that we have, and will allow us to better understand what is happening and how to solve it.

Efficacy and safety of dual vs single renin-angiotensin-aldosterone system blockade in chronic kidney disease: An updated meta-analysis of randomized controlled trials

BACKGROUND

To lower albuminuria and to achieve blood pressure (BP) goals, dual renin-angiotensin-aldosterone system (RAAS) inhibitors are sometimes used in clinical practice for the treatment of CKD. However, the efficacy and safety of dual RAAS blockade therapy remains controversial.

METHODS

PubMed, EMBASE, and Cochrane Library were searched, and random effects model was used to calculate the effect sizes of eligible studies. Potential sources of heterogeneity were detected by meta-regression and subgroup analysis.

RESULTS

The present meta-analysis of 72 randomized controlled trials with 10,296 patients demonstrated that dual RAAS blockade therapy was superior to monotherapy in reducing the urine albumin excretion, urine protein excretion, and BP. These beneficial effects were related to the decrease of glomerular filtration rate, the increase of serum potassium level, and higher rates of hyperkalemia and hypotension. Meanwhile, these effects did not lead to improvements in short-term or long-term outcomes, including doubling of serum creatinine, acute kidney injury, end-stage renal disease, mortality, and hospitalization. Compared with the single therapy, angiotensin-converting enzyme inhibitor (ACEI) in combination with angiotensin-receptor blocker (ARB) was a better dual therapy than ACEI or ARB in combination with renin inhibitor or aldosterone receptor antagonist in decreasing urine albumin excretion, urine protein excretion and BP, and the combination was not associated with a lower glomerular filtration rate.

CONCLUSION

Compared with the single therapy, ACEI in combination with ARB was a better dual therapy than ACEI or ARB in combination with renin inhibitor or aldosterone receptor antagonist. Although ACEI in combination with ARB was associated with higher incidences of hyperkalemia and hypotension, careful individualized management and potassium binders may further expand its application (PROSPERO number CRD42020179398).

Pharmacokinetics and Safety of a Single Dose and Multiple Doses of Allisartan Isoproxil, an Angiotensin II Receptor Blocker, in Healthy Chinese People

Allisartan isoproxil (AI) is a blocker of the angiotensin II type 1 receptor. We evaluated the safety and pharmacokinetics of single- and multiple-dose AI in healthy Chinese individuals. Participants were assigned to receive AI or placebo. Plasma concentration of EXP3174 (carboxylic acid derivative) was measured using liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were determined by noncompartmental methods. Twelve subjects were enrolled, and the ratio of men to women was 5:1. Main pharmacokinetic parameters of EXP3174 after single and multiple doses of AI were a mean maximum concentration in plasma (C_max ) of 2242 ± 1037 ng/mL and median time to reach C_max (T_max ) of 3.5 hours (2.5-8 hours). The median T_max, at steady state was 4.0 hours (1.5-8 hours). The mean C_max at steady state (C_{max, SS} ) was 2047 ± 1050 ng/mL. In terms of EXP3174, there was no significant difference in the C_{max, SS} , area under the curve from time zero to 24 hours of quantifiable concentration at steady state (AUC_{0-24 SS} ), and AUC_0-72 after multiple doses of AI. Serious adverse events did not occur. These data suggest that AI is safe and well tolerated in healthy Chinese individuals at a single dose of 480 or 480 mg once daily for 7 days.

Systematic Review and Meta-Analysis of Renin-Angiotensin-Aldosterone System Blocker Effects on the Development of Cardiovascular Disease in Patients With Chronic Kidney Disease

Background: Cardiovascular events are one of the most serious complications that increase the risk of mortality and morbidity in pre-dialysis and on-dialysis chronic kidney disease (CKD) patients. Activation of the renin-angiotensin-aldosterone system (RAAS) is considered to contribute to the development of cardiovascular events in these populations. Therefore, several kinds of RAAS blockers have been frequently prescribed to prevent cardiovascular events in patients with CKD; however, their effectiveness remains controversial. This systematic review focuses on whether RAAS blockers prevent cardiovascular events in patients with CKD. Method: PubMed were searched to retrieve reference lists of eligible trials and related reviews. Randomized prospective controlled trials that investigated the effects on cardiovascular events in CKD patients that were published in English from 2010 to 2020 were included. Results: Among 167 identified studies, 11 eligible studies (n = 8,322 subjects) were included in the meta-analysis. The meta-analysis showed that RAAS blockers significantly reduced cardiovascular events in on-dialysis patients with CKD [three studies; odds ratio (OR), 0.52; 95% confidence interval (CI), 0.36 to 0.74; p = 0.0003], but there was no significant difference in pre-dialysis patients with CKD because of the heterogeneity in each study (eight studies). We also investigated the effects of each kind of RAAS blocker on cardiovascular events in CKD patients. Among the RAAS blockers, mineralocorticoid receptor antagonists significantly decreased cardiovascular events in pre-dialysis or on-dialysis patients with CKD (four studies; OR, 0.60; 95%CI, 0.50 to 0.73, p < 0.0001). However, angiotensin receptor blockers did not show significant effects (four studies; OR, 0.65; 95%CI, 0.42 to 1.01; p = 0.0529). The effects of angiotensin converting enzyme inhibitors and direct renin inhibitors on cardiovascular events in patients with CKD could not be analyzed because there were too few studies. Conclusion: Mineralocorticoid receptor antagonists may decrease cardiovascular events in pre-dialysis or on-dialysis patients with CKD.

The Angiotensin-converting Enzyme Insertion/Deletion Polymorphism as a Common Risk Factor for Major Pregnancy Complications

Idiopathic pregnancy complications pose a major threat to both maternal and fetal health worldwide. Numerous studies have implicated the role of the renin-angiotensin system (RAS) in the development of obstetric syndromes, since it is crucial for the uteroplacental function. A major RAS component is the angiotensin-converting enzyme (ACE), which hydrolyses angiotensin I to angiotensin II, and not only regulates arterial pressure, but also fibrinolytic activity, indirectly, through the expression of plasminogen activator inhibitor-1. A key functional polymorphism of the ACE gene is the insertion/deletion (I/D) polymorphism, which affects gene expression and product levels, and can therefore lead to high blood pressure and/or reduced fibrinolytic activity. These can cause major pregnancy complications, such as preeclampsia, recurrent pregnancy loss and preterm birth. This review discusses how the ACE I/D is associated with susceptibility towards pregnancy complications, on its own or in combination with other functional gene polymorphisms such, as the angiotensin II receptor type 1 (AT1R) A1166CC, angiotensin II receptor type 2 (AT2R) G1332A, plasminogen activator inhibitor-1 (PAI-1) 4G/5G, matrix metallopeptidase-9 (MMP-9) C1562T, angiotensinogen (AGT) M235T, renin (REN) 83A/G, factor XIII (F13) Val34Leu and endothelial nitric oxide synthase (eNOS) 4a/b.

Extended-release of therapeutic microRNA via a host-guest supramolecular hydrogel to locally alleviate renal interstitial fibrosis

Activated fibroblasts are critical contributors to renal interstitial fibrosis thus becoming the cellular target for fibrosis treatment. Previously, microRNA 29 b (miR-29 b) is shown to be down-regulated in various animal models of renal fibrosis. Herein, we describe a facile strategy to achieve localized and sustained delivery of therapeutic microRNA to the kidney via a host-guest supramolecular hydrogel. Specifically, cationic bovine serum albumin is used to complex with miR-29 b to afford nanocomplexes (cBSA/miR-29 b), which is proven to specifically inhibit fibroblast activation in a dose-dependent manner in vitro. Following unilateral ureteral obstruction in mice, a single injection of the hydrogel loaded with cBSA/miR-29 b in vivo, significantly down-regulated proteins and genes related to fibrosis for up to 21 days without affecting the normal liver or kidney functions. Overall, the localized delivery of cBSA/miR-29 b via a host-guest supramolecular hydrogel represents a safe and effective intervention strategy to delay and reverse the progression of interstitial renal fibrosis.

Implications of oxidative stress in chronic kidney disease: a review on current concepts and therapies

Moderate levels of endogenous reactive oxygen species (ROS) are important for various cellular activities, but high levels lead to toxicity and are associated with various diseases. Levels of ROS are maintained as a balance between oxidants and antioxidants. Accumulating data suggest that oxidative stress is a major factor in deterioration of renal function. In this review, we highlight the possible mechanism by which oxidative stress can lead to chronic kidney disease (CKD). This review also describes therapies that counter the effect of oxidative stress in CKD patients. Numerous factors such as upregulation of genes involved in oxidative phosphorylation and ROS generation, chronic inflammation, vitamin D deficiency, and a compromised antioxidant defense mechanism system cause progressive detrimental effects on renal function that eventually lead to loss of kidney function. Patients with renal dysfunction are highly susceptible to oxidative stress, as risk factors such as diabetes, renal hypertension, dietary restrictions, hemodialysis, and old age predispose them to increased levels of ROS. Biomolecular adducts (DNA, proteins, and lipids) formed due to reaction with ROS can be used to determine oxidative stress levels. Based on the strong correlation between oxidative stress and CKD, reversal of oxidative stress is being explored as a major therapeutic option. Xanthine oxidase inhibitors, dietary antioxidants, and other agents that scavenge free radicals are gaining interest as treatment modalities in CKD patients.

Efficacy and Safety of Angiotensin-Converting Enzyme Inhibitor in Combination with Angiotensin-Receptor Blocker in Chronic Kidney Disease Based on Dose: A Systematic Review and Meta-Analysis

Background: The purpose of this meta-analysis was to evaluate the controversy of angiotensin-converting enzyme inhibitor (ACEI) in combination with angiotensin-receptor blocker (ARB) in the treatment of chronic kidney disease (CKD) based on dose.

Methods: PubMed, EMBASE, and Cochrane Library were searched to identify randomized controlled trials (RCTs) from inception to March 2020. The random effects model was used to calculate the effect sizes. Potential sources of heterogeneity were detected using sensitivity analysis and meta-regression.

Results: This meta-analysis of 53 RCTs with 6,375 patients demonstrated that in patients with CKD, ACEI in combination with ARB was superior to low-dose ACEI or ARB in reducing urine albumin excretion (SMD, −0.43; 95% CI, −0.67 to −0.19; p = 0.001), urine protein excretion (SMD, −0.22; 95% CI, −0.33 to −0.11; p < 0.001), and blood pressure (BP), including systolic BP (WMD, −2.89; 95% CI, −3.88 to −1.89; p < 0.001) and diastolic BP (WMD, −3.02; 95% CI, −4.46 to −1.58; p < 0.001). However, it was associated with decreased glomerular filtration rate (GFR) (SMD, −0.13; 95% CI, −0.24 to −0.02; p = 0.02) and increased rates of hyperkalemia (RR, 2.07; 95% CI, 1.55 to 2.76; p < 0.001) and hypotension (RR, 2.19; 95% CI, 1.35 to 3.54; p = 0.001). ACEI in combination with ARB was more effective than high-dose ACEI or ARB in reducing urine albumin excretion (SMD, −0.84; 95% CI, −1.26 to −0.43; p < 0.001) and urine protein excretion (SMD, −0.24; 95% CI, −0.39 to −0.09; p = 0.002), without decrease in GFR (SMD, 0.02; 95% CI, −0.12 to 0.15; p = 0.78) and increase in rate of hyperkalemia (RR, 0.94; 95% CI, 0.65 to 1.37; p = 0.76). Nonetheless, the combination did not decrease the BP and increased the rate of hypotension (RR, 3.95; 95% CI, 1.13 to 13.84; p = 0.03) compared with high-dose ACEI or ARB.

Conclusion: ACEI in combination with ARB is superior in reducing urine albumin excretion and urine protein excretion. The combination is more effective than high-dose ACEI or ARB without decreasing GFR and increasing the incidence of hyperkalemia. Despite the risk of hypotension, ACEI in combination with ARB is a better choice for CKD patients who need to increase the dose of ACEI or ARB (PROSPERO CRD42020179398).

Association between renin-angiotensin system and chronic lung allograft dysfunction

Chronic lung allograft dysfunction (CLAD) is the major cause of death after lung transplantation. Angiotensin II (AngII), the main effector of the renin-angiotensin (RA) system, elicits fibrosis in both kidney and lung. We identified 6 AngII-regulated proteins (RHOB, BST1, LYPA1, GLNA, TSP1, LAMB1) increased in urine of patients with kidney allograft fibrosis. We hypothesized that RA system is active in CLAD and that AngII-regulated proteins are increased in bronchoalveolar lavage fluid (BAL) of CLAD patients.We performed immunostaining of AngII receptors (AGTR1 and AGTR2) and TSP1/GLNA in 10 CLAD lungs and 5 controls. Using mass spectrometry, we quantified peptides corresponding to AngII-regulated proteins in BAL of 40 lung transplant recipients (CLAD, stable and acute lung allograft dysfunction (ALAD)). Machine learning algorithms were developed to predict CLAD based on BAL peptide concentrations.Immunostaining demonstrated significantly more AGTR1+ cells in CLAD versus control lungs (p=0.02). TSP1 and GLNA immunostaining positively correlated with the degree of lung fibrosis (R²=0.42 and 0.57, respectively). In BAL, we noted a trend toward higher concentrations of AngII-regulated peptides in patients with CLAD at the time of bronchoscopy, and significantly higher concentrations of BST1, GLNA and RHOB peptides in patients that developed CLAD at follow-up (p<0.05). Support vector machine classifier discriminated CLAD from stable and ALAD patients at the time of bronchoscopy with AUC 0.86, and accurately predicted subsequent CLAD development (AUC 0.97).Proteins involved in the RA system are increased in CLAD lung and BAL. AngII-regulated peptides measured in BAL may accurately identify patients with CLAD and predict subsequent CLAD development.

Association of Blood Pressure Genetic Risk Score with Cardiovascular Disease and CKD Progression: Findings from the CRIC Study

Background

In the general population, genetic risk for high BP has been associated with cardiovascular disease, but not kidney function or incident CKD. These relationships have not been studied longitudinally in participants with CKD. We examined whether BP genetic risk predicts cardiovascular disease and kidney disease progression in patients with CKD.

Methods

We included 1493 African- and 1581 European-ancestry participants from the Chronic Renal Insufficiency Cohort who were followed for 12 years. We examined associations of BP genetic risk scores with development of cardiovascular disease (myocardial infarction, congestive heart failure, or stroke) and CKD progression (incident ESKD or halving of eGFR) using Cox proportional hazards models. Analyses were stratified by race and included adjustment for age, sex, study site, and ancestry principal components.

Results

Among European-ancestry participants, each SD increase in systolic BP and pulse pressure genetic risk score conferred a 15% (95% CI, 4% to 27%) and 11% (95% CI, 1% to 23%), respectively, higher risk of cardiovascular disease, with a similar, marginally significant trend for diastolic BP. Among African-ancestry participants, each SD increase in systolic and diastolic BP genetic risk score conferred a 10% (95% CI, 1% to 20%) and 9% (95% CI, 0% to 18%), respectively, higher risk of cardiovascular disease. Higher genetic risk was not associated with CKD progression.

Conclusions

Genetic risk for elevation in BP was associated with increased risk of cardiovascular disease, but not CKD progression.

An injectable micelle-hydrogel hybrid for localized and prolonged drug delivery in the management of renal fibrosis

Localized delivery, comparing to systemic drug administration, offers a unique alternative to enhance efficacy, lower dosage, and minimize systemic tissue toxicity by releasing therapeutics locally and specifically to the site of interests. Herein, a localized drug delivery platform ("plum‒pudding" structure) with controlled release and long-acting features is developed through an injectable hydrogel ("pudding") crosslinked via self-assembled triblock polymeric micelles ("plum") to help reduce renal interstitial fibrosis. This strategy achieves controlled and prolonged release of model therapeutics in the kidney for up to three weeks in mice. Following a single injection, local treatments containing either anti-inflammatory small molecule celastrol or anti-TGFβ antibody effectively minimize inflammation while alleviating fibrosis via inhibiting NF-κB signaling pathway or neutralizing TGF-β1 locally. Importantly, the micelle-hydrogel hybrid based localized therapy shows enhanced efficacy without local or systemic toxicity, which may represent a clinically relevant delivery platform in the management of renal interstitial fibrosis.

The water expelling effect evaluation of 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol and ingenol on H22 mouse hepatoma ascites model and their content differences analysis in Euphorbia kansui before and after stir-fried with vinegar by UPLC

ETHNOPHARMACOLOGICAL RELEVANCE

Malignant ascites (MA) effusion is mainly caused by hepatocellular, ovarian, and breast cancer etc. It has been reported that Euphorbia kansui (EK), the root of Euphorbia kansui S.L.Liou ex S.B.Ho, possessing a therapeutic effect on MA. However, the clinical applications of EK are seriously restricted for its severe toxicity. Although studies demonstrated that vinegar-processing can reduce the toxicity and retain the water expelling effect of EK, its specific mechanism remains unknown.

AIM OF THE STUDY

This study aims to explore the underlying mechanisms of toxicity reduction without compromising the pharmacological effects of EK stir-fried with vinegar (VEK).

MATERIALS AND METHODS

3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol (3-O-EZ), a major diterpenoid of EK, could convert into ingenol after processing EK with vinegar. The H22 mouse hepatoma ascites model was replicated, and were given 3-O-EZ and ingenol seven days (110.14, 50.07 and 27.54 mg/kg). The histopathological observation, serum liver enzymes, serum Renin-Angiotensin-Aldosterone System (RAAS) levels, ascites volumes, pro-inflammatory cytokines levels and H22 cells apoptosis in ascites were examined. Then the intestine (Aquaporin 8, AQP8) and kidney (Aquaporin 2, AQP2; Vasopressin type 2 receptor, V2R) protein expression were detected, as well as the metabolomics of serum were analyzed. Finally, the content of 3-O-EZ and ingenol in EK and VEK were investigated.

RESULTS

3-O-EZ and ingenol can relieve hepatic and gastrointestinal injuries, reduce ascites volumes, enhance the H22 cells apoptosis, ameliorate abnormal pro-inflammatory cytokines and RAAS levels, and down-regulate the expression of AQP8, AQP2, V2R. The involved metabolic pathways mainly included glycerophospholipid metabolism and arachidonic acid metabolism. And the decreasing rate of 3-O-EZ in VEK was 19.14%, the increasing rate of ingenol in VEK was 92.31%.

CONCLUSION

3-O-EZ and ingenol possess significant effect in treating MA effusion, while ingenol has lower toxicity compared with 3-O-EZ. And provide evidence for the mechanism of attenuation in toxicity without compromising the pharmacological effects of VEK.

[The renin-angiotensin system and the brain]

The renin-angiotensin-aldosterone (RAAS) system and its effects on blood pressure and the regulation of water and electrolyte balance have been studied focusing on the cardiovascular and renal system. The activation of RAAS in other organs has local and systemic repercussions by modeling the macro- and microvasculture of peripheral organs. The brain RAAS influence on systemic blood pressure through the sympathetic nervous system. The angiotensin converting enzyme/angiotensin II/angiotensin 1 receptor axis (ACE/AngII/AT1), classical pathway, and angiotensin converting enzyme type 2/angiotensin (1-7)/Mas receptor (ACE2/Ang (1-7)/MasR), non-classical pathway, are involved in the modulation of the sympathetic response. The imbalance of these two axes with subsequently Ang II accumulation promote neurogenic hypertension and other vascular pathologies. The aminopeptidase/angiotensin IV/angiotensin 4 receptor (AMN/Ang IV/AT4) axis, which is exclusive of the brain, acts on cerebral microvasculature and participates in cognition, memory, and learning. The aim of this review is to decipher the major central RAAS mechanisms involved in blood pressure regulation. In addition, paracrine functions of brain RAAS and its role in neuroprotection and cognition are also described in this review.

Novel antihypertensive action of rutin is mediated via inhibition of angiotensin converting enzyme/mineralocorticoid receptor/angiotensin 2 type 1 receptor (ATR1) signaling pathways in uninephrectomized hypertensive rats

Hypertension is the most common cardiovascular disease that affects approximately 26% of adult population, worldwide. Rutin is one of the important flavonoids that is consumed in the daily diet, and found in many food items, vegetables, and beverages. Uninephrectomy (UNX) of the left kidney was performed, followed by induction of hypertension. The rats were randomly divided into four groups of 10 rats: group 1-Sham-operated rats; group 2-UNX rats, group 3-UNX-L-NAME (40 mg/kg) plus rutin (100 mg/kg bwt), and groups 4-UNX-L-NAME plus lisinopril (10 mg/kg bwt), orally for 3 weeks. Results revealed significant heightening of arterial pressure and oxidative stress indices, while hypertensive rats treated with rutin had lower expressions of angiotensin converting enzyme (ACE) and mineralocorticoid receptor in uninephrectomized rats. Together, rutin as a novel antihypertensive flavonoid could provide an unimaginable benefits for the management of hypertension through inhibition of angiotensin converting enzyme and mineralocorticoid receptor. PRACTICAL APPLICATIONS: Hypertension has been reported to be the most common cardiovascular disease, affecting approximately 26% of the adult population worldwide with predicted prevalence to increase by 60% by 2025. Recent advances in phytomedicine have shown flavonoids to be very helpful in the treatment of many diseases. Flavonoids have been used in the treatment and management of cardiovascular diseases, obesity and hypertension. The study revealed that rutin, a known flavonoid inhibited angiotensin converting enzyme (ACE), angiotensin 2 type 1 receptor (ATR1), and mineralocorticoid receptor (MCR), comparable to the classic ACE inhibitor, Lisinopril, indicating the novel antihypertensive property of rutin. Therefore, flavonoids such as rutin found in fruits and vegetables could, therefore, serve as an antihypertensive drug regimen. Combining all, functional foods rich in flavonoids could be used as potential therapeutic candidates for managing uninephrectomized hypertensive patients.

The efficacy and safety of SGLT2 inhibitors combined with ACEI/ARBs in the treatment of type 2 diabetes mellitus: A meta-analysis of randomized controlled studies

BACKGROUND

The efficacy and safety of the combination therapy with sodium-glucose cotransporter 2 (SGLT2) inhibitors and angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARBs) in the treatment of type 2 diabetes mellitus (T2DM) was not clear yet.

RESEARCH DESIGN AND METHODS

A meta-analysis of randomized controlled studies (RCTs) was performed by searching in CENTRAL, Web of Science, PubMed, and Embase.

RESULTS

Eight RCTs involving 6,386 participants were finally enrolled in this meta-analysis. Compared with placebo plus ACEI/ARBs, combined therapy with SGLT2 inhibitors and ACEI/ARBs induced a significant reduction in glycated hemoglobin (HbA1c) level by 0.43% (95% confidence interval [CI]: -0.55, -0.31), fasting plasma glucose level by 16.51 mg/dL (95% CI: -21.94, -11.08); systolic/diastolic blood pressure (BP) by 5.34 mmHg (95% CI: -7.47, -3.21)/1.27 mmHg (95% CI: -1.95, -0.59), respectively; and body weight (BW) by 1.45 kg (95% CI: -2.24, -0.65). Combined therapy was also found to be associated with a lower risk of adverse events. However, a higher risk of genital infections was observed with combination therapy than with placebo.

CONCLUSIONS

This combination therapy showed satisfactory effects on lowering glycemic, BW, and BP in the treatment of T2DM patients. The safety of this combination therapy was also acceptable.

The renin-angiotensin-aldosterone system as a link between obesity and coronavirus disease 2019 severity

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory distress coronavirus 2 (SARS-CoV2), is a rapidly evolving pandemic challenging the world and posing unprecedented public health issues. Current data show that COVID-19 is associated with increased disease severity in individuals with obesity. Obesity is usually associated with dysregulated renin-angiotensin-aldosterone (RAAS) axis. RAAS has also been implicated in acute lung injury as well as myocardial injury and has thus attracted interest as a potential regulator of COVID-19 severity. Whilst research all over the world is still struggling to provide a detailed characterization of the biology of SARS-CoV2 and its associated disease profile, it has become evident that SARS-CoV2 uses the membrane-bound form of angiotensin-converting enzyme 2 (ACE2) as a receptor for cell internalization. ACE2 is a protective component of the RAAS axis and is downregulated after SARS-CoV2 infection. The RAAS axis could thus be a link between obesity and COVID-19 severity; therefore, more accurate understanding of the underlying mechanisms would be needed with the hope of proposing efficient therapeutic interventions.