The Therapeutic Strategies for Uremic Toxins Control in Chronic Kidney Disease

Comprehensive review of leonurine: harnessing its therapeutic potential for chronic diseases

Chronic diseases (CD) pose a significant global health challenge, affecting millions of individuals and contributing to substantial morbidity, mortality, and healthcare burden. Therapeutic approaches primarily aim at symptom management through pharmacotherapy, lifestyle modifications, dietary interventions, and regular physical activity. Given the persistent challenge of limited treatment options, scientific research has increasingly focused on exploring natural compounds for their therapeutic potential. Leonurine, a natural compound first isolated from the plant Herba leonuri in 1930, has garnered significant attention due to its extensive pharmacological properties relevant to the treatment of CDs. Extensive studies over the past have revealed that leonurine exhibits anticancer, antidiabetic, anti-inflammatory, and antioxidant activities. These effects are mediated through the modulation of various signaling pathways, including the TGF-β/Smad2, Nrf-2, JNK, NF-κB, BDNF/TrkB/CREB, TLR4/NF-κB/TNF-α, ATF4/CHOP/ASCL4, Akt, HIF-1, SHH/GLI, and mTOR/ERK, whose dysregulation is implicated in the pathogenesis of various CDs. Furthermore, leonurine regulates the levels of multiple pro-inflammatory cytokines, including numerous interleukins and TNF-α, indicating its potential in treating a wide range of chronic conditions, including cardiovascular, neurological, skeletal, and renal diseases. This review seeks to present an in-depth analysis of leonurine's therapeutic potential, emphasizing its promise in the management of various CDs. It also outlines potential avenues for future research to fully harness its pharmacological advantages in treating these conditions.

Preparation, in vitro and in vivo evaluation and anti-renal injury effects of Niazimicin-loaded mixed polymeric micelles

BACKGROUND

Chronic Kidney Disease (CKD) has become one of the major life-threatening conditions. Moringa seeds have been reported to exhibit renoprotective effects, with Niazimicin as its characteristic component.

OBJECTIVE

To investigate the anti-renal injury effects of Niazimicin and its mixed micelles (N-M) that composed of monomethyl ether poly (ethylene glycol)-polycaprolactone (mPEG-PCL) and polyethylene glycolated chitosan (PEG-CS) on adenine-induced CKD mice.

METHODS

PEG-CS was prepared via formaldehyde linkage method. The thin film dispersion method was employed for the preparation of N-M before it was characterized in vivo and in vitro. The anti-renal injury effects were evaluated by analyzing the serum levels of creatinine (Cr), p-Cresol sulphate (pCs), indole sulphate (IS) and hematoxylin-eosin (HE)-stained sections of hepatic and renal pathological tissues in CKD mice.

RESULTS

The N-M were spherical micelles of uniform size and highly dispersed with particle size of 42.94 ± 0.58 nm, encapsulation efficiency (EE) of 97.73 ± 2.33% and drug loading (DL) of 16.17 ± 0.28%, as well as good stability, and a very low critical micelle concentration (CMC) value of 0.00731 mg/mL. The N-M had a delayed-release effect and higher oral bioavailability compared to Niazimicin.

CONCLUSION

In CKD mice, Niazimicin exhibited an anti-renal injury effect, while the renoprotective effect of N-M was superior to that of Niazimicin.

Multiple metabolic analysis of [18F]FDG PET/CT in patients with kidney disease

Purpose

This study aimed to evaluate the value of [18F]FDG PET/CT in patients with kidney disease by using multiple metabolic parameters.

Materials and methods

A retrospective review of 182 kidney disease patients and 32 controls was conducted. Patients were categorized into acute kidney disease (AKD), AKI on CKD (A/C), and chronic kidney disease (CKD) groups, further divided by CKD stage and disease etiology. Regions of interest (ROIs) were drawn in renal cortex, liver, aorta, and lesions. SUVmax and SUVmean were measured, and ratios of renal cortex SUVmax to liver and blood pool SUVmean were calculated.

Results

Abnormal FDG uptake was observed in 84.6 % of patients, with significantly higher SUVmax in malignant versus benign lesions. Common malignancies included multiple myeloma, lymphoma, and lung cancer. PET/CT had 89.5 % sensitivity and 100 % specificity for tumor detection. SUVs differed significantly among AKD, A/C, CKD, and normal groups. Significant differences in SUVmax and SUVmean were also found between CKD stages and primary versus secondary kidney diseases. In CKD, increased SUVmax and SUVmean correlated with lower serum creatinine and blood urea nitrogen, and increased eGFR.

Conclusion

For patients with kidney disease, [18F]FDG PET/CT can be used to systematically screen tumors and inflammatory lesions. And the [18F]FDG uptake of renal cortex may distinguish different types of kidney diseases and is correlated with renal function.

Role of Uremic Toxins, Oxidative Stress, and Renal Fibrosis in Chronic Kidney Disease

Affecting millions of people worldwide, chronic kidney disease is a serious medical problem. It results in a decrease in glomerular filtration rate below 60 mL/min/1.73 m, albuminuria, abnormalities in urine sediment and pathologies detected by imaging studies lasting a minimum of 3 months. Patients with CKD develop uremia, and as a result of the accumulation of uremic toxins in the body, patients can be expected to suffer from a number of medical consequences such as progression of CKD with renal fibrosis, development of atherosclerosis or increased incidence of cardiovascular events. Another key element in the pathogenesis of CKD is oxidative stress, resulting from an imbalance between the production of antioxidants and the production of reactive oxygen species. Oxidative stress contributes to damage to cellular proteins, lipids and DNA and increases inflammation, perpetuating kidney dysfunction. Additionally, renal fibrogenesis involving the accumulation of fibrous tissue in the kidneys occurs. In our review, we also included examples of forms of therapy for CKD. To improve the condition of CKD patients, pharmacotherapy can be used, as described in our review. Among the drugs that improve the prognosis of patients with CKD, we can include: GLP-1 analogues, SGLT2 inhibitors, Finerenone monoclonal antibody-Canakinumab and Sacubitril/Valsartan.

Predicting COVID-19 Re-Positive Cases in Malnourished Older Adults: A Clinical Model Development and Validation

Purpose

Building and validating a clinical prediction model for novel coronavirus (COVID-19) re-positive cases in malnourished older adults.

Patients and Methods

Malnourished older adults from January to May 2023 were retrospectively collected from the Department of Geriatrics of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine. They were divided into a "non-re-positive" group and a "re-positive" group based on the number of COVID-19 infections, and into a training set and a validation set at a 7:3 ratio. The least absolute shrinkage and selection operator (LASSO) regression analysis was used to identify predictive factors for COVID-19 re-positivity in malnourished older adults, and a nomogram was constructed. Independent influencing factors were screened by multivariate logistic regression. The model's goodness-of-fit, discrimination, calibration, and clinical impact were assessed by Hosmer-Lemeshow test, area under the curve (AUC), calibration curve, decision curve analysis (DCA), and clinical impact curve analysis (CIC), respectively.

Results

We included 347 cases, 243 in the training set, and 104 in the validation set. We screened 10 variables as factors influencing the outcome. By multivariate logistic regression analysis, preliminary identified protective factors, risk factors, and independent influencing factors that affect the re-positive outcome. We constructed a clinical prediction model for COVID-19 re-positivity in malnourished older adults. The Hosmer-Lemeshow test yielded χ2 =5.916, P =0.657; the AUC was 0.881; when the threshold probability was >8%, using this model to predict whether malnourished older adults were re-positive for COVID-19 was more beneficial than implementing intervention programs for all patients; when the threshold was >80%, the positive estimated value was closer to the actual number of cases.

Conclusion

This model can help identify the risk of COVID-19 re-positivity in malnourished older adults early, facilitate early clinical decision-making and intervention, and have important implications for improving patient outcomes. We also expect more large-scale, multicenter studies to further validate, refine, and update this model.

Displacing the Burden: A Review of Protein-Bound Uremic Toxin Clearance Strategies in Chronic Kidney Disease

Uremic toxins (UTs), particularly protein-bound uremic toxins (PBUTs), accumulate in chronic kidney disease (CKD) patients, causing significant health complications like uremic syndrome, cardiovascular disease, and immune dysfunction. The binding of PBUTs to plasma proteins such as albumin presents a formidable challenge for clearance, as conventional dialysis is often insufficient. With advancements in the classification and understanding of UTs, spearheaded by the European Uremic Toxins (EUTox) working group, over 120 molecules have been identified, prompting the development of alternative therapeutic strategies. Innovations such as online hemodiafiltration aim to enhance the removal process, while novel adsorptive therapies offer a means to address the high affinity of PBUTs to plasma proteins. Furthermore, the exploration of molecular displacers, designed to increase the free fraction of PBUTs, represents a cutting-edge approach to facilitate their dialytic clearance. Despite these advancements, the clinical application of displacers requires more research to confirm their efficacy and safety. The pursuit of such innovative treatments is crucial for improving the management of uremic toxicity and the overall prognosis of CKD patients, emphasizing the need for ongoing research and clinical trials.

Investigating the Efficacy of Kidney-Protective Lactobacillus Mixture-Containing Pet Treats in Feline Chronic Kidney Disease and Its Possible Mechanism

Microbiota-based strategies are a novel auxiliary therapeutic and preventative way of moderating chronic kidney disease (CKD). Lactobacillus mixture (Lm) was previously demonstrated to exert a renal-protective function in the CKD mice model. The efficacy of probiotics in pet foods is a relatively new area of study, and thus verifying the potential health benefits is necessary. This study evaluated the efficacy of Lm treats in feline CKD and elucidated the mechanisms underlying host-microbe interactions. CKD cats (2 and 3 stages) were administrated probiotic pet treats daily (10 g) for 8 weeks. The results demonstrated that during the eight weeks of Lm administration, creatinine was reduced or maintained in all cats with CKD. Similarly, gut-derived uremic toxin (GDUT), indoxyl sulfate (IS), were potential clinical significance in IS after Lm treatment (confidence intervals = 90%). The life quality of the cats also improved. Feline gut microbiome data, metabolic functional pathway, and renal function indicator analyses revealed the possible mechanisms involved in modulating CKD feline microbial composition. Further regulation of the microbial functions in amino acid metabolism after Lm administration contributed to downregulating deleterious GDUTs. The current study provides potential adjuvant therapeutic insights into probiotic pet foods or treats for pets with CKD.

Exploring the clinical efficacy and mechanism of high-position colon dialysis combined with Traditional Chinese Medicine retention enema in real-world patients with stage 3-5 chronic kidney disease (non-dialysis) based on the theory of the Gut-Kidney axis

Background: With societal and economic development, the annual incidence of chronic kidney disease (CKD) is increasing. Current treatments for CKD are limited, and once patients progress to the uraemic stage, it places a significant economic burden on families and society. Based on the "gut-kidney axis" theory and real-world research, this study aims to evaluate the clinical efficacy, safety, and potential mechanism of high-position colon dialysis combined with traditional Chinese medicine (TCM) retention enema in treating stage 3-5 chronic kidney disease (non-dialysis). Additionally, it seeks to identify new therapeutic targets and approaches for CKD treatment. Methods: The TCM decoction was analyzed using Ultra-Performance Liquid Chromatography-Quadrupole-Orbitrap-High Resolution Mass Spectrometry (UPLC-Q-Orbitrap-HRMS). Participants meeting the inclusion criteria were divided into a control group (n = 153) and a treatment group (n = 159) based on their preferences and physicians' recommendations. Both groups adhered to a high-quality low-protein, low-salt, low-phosphorus, and low-fat diet supplemented with essential amino acids, and were monitored for blood pressure, blood glucose, and blood lipids. The treatment group received high-position colon dialysis combined with TCM retention enemas (administered at least 12 times every other day). Results: Thirteen compounds were identified from the herbs by UPLC-Q-Orbitrap-HRMS. The CKD3-5 treatment group exhibited improvements in blood biochemistry and other laboratory indices, with significant enhancements in renal function-related indices for CKD4 and CKD5 stages (p < 0.05). Following treatment, indoxyl sulfate (IS), endotoxin, and D-lactic acid levels decreased to a certain extent in both groups, with a statistically significant difference observed within the treatment group (p < 0.05). The treatment group displayed a significant reduction in aerobic bacterial colonies, an increase in anaerobic bacterial colonies, a decrease in Escherichia coli colonies, and an increase in Bifidobacterium and Lactobacillus colonies (p < 0.05). No significant changes in colony numbers were observed in the control group. Conclusion: High-position colon dialysis combined with TCM retention enema may serve as an adjuvant treatment for CKD4-5 (non-dialysis), and its mechanism may be related to the reduction of uraemic toxins, improvement of intestinal mucosal barrier function, and regulation of intestinal microecology. Clinical Trial Registration: https://www.chictr.org.cn/, identifier ChiCTR2200062852.

Exploring a Complex Interplay: Kidney-Gut Axis in Pediatric Chronic Kidney Disease

The human intestinal microbiota is a highly intricate structure with a crucial role in promoting health and preventing disease. It consists of diverse microbial communities that inhabit the gut and contribute to essential functions such as food digestion, nutrient synthesis, and immune system development. The composition and function of the gut microbiota are influenced by a variety of factors, including diet, host genetics, and environmental features. In pediatric patients, the gut microbiota is particularly dynamic and vulnerable to disruption from endogenous and exogenous factors. Recent research has focused on understanding the interaction between the gut and kidneys. In individuals with chronic kidney disease, there is often a significant disturbance in the gut microbiota. This imbalance can be attributed to factors like increased levels of harmful toxins from the gut entering the bloodstream, inflammation, and oxidative stress. This review looks at what is known about the link between a child's gut-kidney axis, how dysbiosis, or an imbalance in the microbiome, affects chronic kidney disease, and what treatments, both pharmaceutical and non-pharmaceutical, are available for this condition.

Chronic kidney disease and gut microbiota

Chronic kidney disease (CKD) refers to a range of various pathophysiological processes correlated with abnormal renal function and a progressive loss in GFR. Just as dysbiosis and altered pathology of the gut are accompanied with hypertension, which is a significant CKD risk factor. Gut dysbiosis in CKD patients is associated with an elevated levels of uremic toxins, which in turn increases the CKD progression. According to research results, the gut-kidney axis has a role in the formation of kidney stones, also in IgAN. A number of researchers have categorized the gut microbiota as enterotypes, and others, skeptical of theory of enterotypes, have suggested biomarkers to describe taxa that related to lifestyle, nutrition, and disease status. Metabolome-microbiome studies have been used to investigate the interactions of host-gut microbiota in terms of the involvement of metabolites in these interactions and are yielded promising results. The correlation between gut microbiota and CKD requires further multi-omic researches. Also, with regard to systems biology, studies on the communication network of proteins and transporters such as SLC and ABC, can help us achieve a deeper understanding of the gut-liver-kidney axis communication and can thus provide promising new horizons in the treatment of CKD patients. Probiotic-based treatment is an approach to reduce uremic poisoning, which is accomplished by swallowing microbes those can catalyze URS in the gut. If further comprehensive studies are carried out, we will know about the probiotics impact in slowing the renal failure progression and reducing inflammatory markers.

Meta-analysis of cancer risk among end stage renal disease undergoing maintenance dialysis

Currently, there is no consensus on whether maintenance dialysis increases cancer risk in patients with end-stage renal disease (ESRD). Therefore, this study was to systematically evaluate the risk of cancer among ESRD patients undergoing maintenance dialysis. Related studies on the impact of maintenance dialysis on cancer risk were retrieved from PubMed, Embase, Cochrane Library, and other databases from their respective inceptions to 19 February 2021. ESRD patients receiving maintenance dialysis were classified into cancer including non-melanoma skin cancer (NMSC) and cancer excluding NMSC. Standardized incidence ratio (SIR) with its 95% confidence interval (95% CI) was calculated to assess cancer risk. Fourteen studies were included in the meta-analysis. The risk of cancer in patients undergoing maintenance dialysis (with or without NMSC) was significantly higher than controls both in cancer including NMSC (SIR = 1.38, 95% CI: 1.27-1.49, P < 0.001) and cancer excluding NMSC (SIR = 1.34, 95% CI: 1.23-1.47, P < 0.001). Subgroup results identified the higher risk of cancer incidence in both men and women receiving maintenance dialysis. Meanwhile, elevated excess risks were observed among patients with younger age and shorter follow-up time (P < 0.001). Meanwhile, the combined SIR of bladder, cervix, colorectum, kidney, liver, thyroid, tongue, and other cancers were all increased (P < 0.05). ESRD patients undergoing dialysis has higher risk of cancer.

Panax notoginseng saponins alleviate damage to the intestinal barrier and regulate levels of intestinal microbes in a rat model of chronic kidney disease

OBJECTIVES

Chronic kidney disease (CKD) is a long-term condition characterized by poor prognosis and a high mortality rate. Panax notoginseng saponins (PNS) are the main active ingredient of the traditional Chinese herb Panaxnotoginseng(Burk.)F.H.Chen, which has been widely reported to have various pharmacological effects. Here, we examined the effect of PNS on renal function and the modulation of intestinal flora and intestinal barrier in a rat model of adenine-induced CKD.

METHODS

Adenine was used to establish a rat model of CKD, biochemical testing, histopathologic examination, ELISA, immunohistochemical assay, western blot assay, and fecal microbiota 16s rRNA analysis was used to test the effect of PNS on CKD rats.

RESULTS

Adenine induced a significant decrease in glomerular filtration rate, an increase in urinary protein excretion rate, and pathological damage to renal tissue in CKD rats. TNF-α, MCP-1, IL-1β, IL-18, TMAO, and endotoxin levels were increased in the blood of the model rats. Application of PNS countered the effects of adenine, restoring the above parameters to the level observed in healthy rats. In addition, activation of the inflammatory proteins NF-κB (p65) and NLRP3 and the fibrosis-associated proteins α-SMA and smad3 were inhibited in the kidneys of CKD rats. Furthermore, PNS promoted the expression of the tight junction proteins Occludin and ZO-1, increased SIgA levels, strengthened intestinal immunity, reduced mechanical damage to the intestine, was reduced levels of DAO and D-LA. Our data suggest PNS may delay CKD by restoring gut microbiota, and through the subsequent generation of a microbial barrier and modulation of microbiota metabolites.

CONCLUSIONS

In conclusion, PNS may inhibit the development of inflammation and fibrosis in the kidney tissue through regulation of intestinal microorganisms and inhibition of the activation of pro-inflammatory and pro-fibrotic proteins in the kidney.

Indoxyl Sulfate Alters the Humoral Response of the ChAdOx1 COVID-19 Vaccine in Hemodialysis Patients

Background and aims: Vaccination for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is strongly recommended. The efficacy of SARS-CoV-2 vaccine for patients with end-stage renal disease is low. Indoxyl sulfate (IS) is a representative protein bound uremic toxin arousing immune dysfunction in CKD patients. It is unknown whether IS impairs the efficacy of vaccines for SARS-CoV-2. Materials and Methods: From 1 June 2021, to 31 December 2021, hemodialysis patients (n = 358) and a control group (n = 59) were eligible to receive the first dose of the ChAdOx1 COVID-19 vaccine. Titer measurements indicative of the humoral response (anti-S1 IgG and surrogate virus neutralization test (sVNT) results) and indoxyl sulfate concentration measurement were performed 4 weeks after ChAdOx1 vaccine injection. Results: The serum concentrations of anti-S1 IgG were 272 ± 1726 AU/mL and 2111 ± 4424 AU/mL in hemodialysis patients and control group (p < 0.05), respectively. The sVNT values were 26.8 ± 21.1% and 54.0 ± 20.2% in the hemodialysis and control groups (p < 0.05), respectively. There was a decreasing trend for the anti-S1 IgG titer from the lowest to highest quartile of IS (p < 0.001). The patients with higher concentrations of IS had lower sVNT (p for trend < 0.001). Conclusion: Hemodialysis patients had weaker humoral immunity after the first dose of the ChAdOx1 vaccine. Higher concentration of IS altered the development of anti-S1 antibodies and sVNT-measured neutralization.

POTENTIAL THERAPEUTIC OPTIONS TARGETING THE GUT DYSBIOSIS IN CHRONIC KIDNEY DISEASE

The gut microbiota plays an important physiological role in controlling not only the function of the gastrointestinal tract, but also in maintaining systemic homeostasis. Quantitative and /or qualitative disturbances of the gut microbiota (dysbiosis) are an important element in the complex pathogenesis of many diseases, including chronic kidney disease (CKD). In the disease, the mutual interactions between disturbed gut microbiota and the progression of CKD (pathophysiological "kidney-gut axis") have been demonstrated. The kidney failure causes water and nitrogen waste retention which leads to disturbances of motility, secretion and absorption in the gastrointestinal tract. These abnormalities contribute to the development of gut dysbiosis, accompanied by overproduction of toxic bacterial metabolites, with their translocation to the peripheral blood and development of endotoxemia. As a consequence, chronic kidney "low-grade" inflammation and oxidative stress develop, with further deterioration of kidney function in the mechanism of the "vicious cycle" of the kidney-gut axis. Considering the key role of gut dysbiosis and the kidney-gut axis, the attempts to restore the gut eubiosis seem to have an important role in the treatment of CKD and may be even regarded as a form of causal therapeutic intervention. The paper briefly discusses the basics of the pathophysiological kidney-gut axis in CKD and potential methods of modulating the abnormal gut microbiota in this disease, including the use of probiotic or prebiotic preparations, agents that absorb bacterial-derived toxins in the intestinal lumen, fecal microbiota transplantation and drugs used so far for other indications (acarbose, meclofenamate, lubiprostone).

Targeting SYK of monocyte-derived macrophages regulates liver fibrosis via crosstalking with Erk/Hif1α and remodeling liver inflammatory environment

Liver fibrosis is a danger signal indicating a huge risk of liver cancer occurrence, but there is still no effective clinical means to regulate the progress of liver fibrosis. Although a variety of drugs targeting SYK have been developed for tumors and autoimmune diseases, the mechanism and specific efficacy of SYK's role in liver fibrosis are not yet clear. Our studies based on chronic CCL4, bile duct ligation, and subacute TAA mouse models show that SYK in monocyte-derived macrophages (MoMFs) is fully dependent on phosphorylation of Erk to up-regulate the expression of Hif1α, thereby forming the crosstalk with SYK to drive liver fibrosis progress. We have evaluated the ability of the small molecule SYK inhibitor GS9973 in a variety of models. Contrary to previous impressions, high-frequency administration of GS9973 will aggravate CCL4-induced liver fibrosis, which is especially unsuitable for patients with cholestasis whose clinical features are bile duct obstruction. In addition, we found that inhibition of MoMFs SYK impairs the expression of CXCL1, on one hand, it reduces the recruitment of CD11bhiLy6Chi inflammatory cells, and on the other hand, it promotes the phenotype cross-dress process of pro-resolution MoMFs, thereby remodeling the chronic inflammatory environment of the fibrotic liver. Our further findings indicate that on the basis of the administration of CCR2/CCR5 dual inhibitor Cenicriviroc, further inhibiting MoMFs SYK may give patients with fibrosis additional benefits.

Effects of Uremic Clearance Granules in Uremic Pruritus: A Meta-Analysis

Uremic pruritus is common among patients with advanced or end-stage renal disease, with an incidence of >40% among patients on dialysis. Uremic clearance granules (UCGs) are effective in managing uremic pruritus and delay the progression of chronic kidney disease. We conducted a systematic review and a meta-analysis to evaluate the efficacy of UCG in patients with uremic pruritus. Several electronic databases were searched systematically from their inceptions until 19 July 2021. Randomized control trials evaluating the efficacy of UCG in patients with uremic pruritus were selected. Eleven trials including 894 participants were published between 2011 and 2021. Patients administered UCGs had a significantly decreased visual analog scale score (mean difference [MD], -2.02; 95% confidence interval [CI], -2.17 to -1.88), serum levels of hsCRP (MD, -2.07 mg/dL; 95% CI, -2.89 to -1.25; p < 0.00001), TNF-α (MD, -15.23 mg/L; 95% CI, -20.00 to -10.47; p < 0.00001]), β2-MG (MD, -10.18 mg/L; 95% CI, -15.43 to -4.93; p < 0.00001), and IL-6 (MD, -6.13 mg/L; 95% CI, -7.42 to -4.84; p < 0.00001). In addition, UCGs significantly reduced serum levels of creatinine, BUN, PTH, iPTH, phosphorus, and the overall effectiveness rate. UCGs could be an attractive complementary therapy for patients with uremic pruritus.