Uremic Toxins Activate Macrophages

Hyperoside ameliorates cisplatin-induced acute kidney injury by regulating the expression and function of Oat1

Cisplatin is a widely used chemotherapeutic agent to treat solid tumours in clinics. However, cisplatin-induced acute kidney injury (AKI) limits its clinical application. This study investigated the effect of hyperoside (a flavonol glycoside compound) on regulating AKI.The model of cisplatin-induced AKI was established, and hyperoside was preadministered to investigate its effect on improving kidney injury.Hyperoside ameliorated renal pathological damage, reduced the accumulation of SCr, BUN, Kim-1 and indoxyl sulphate in vivo, increased the excretion of indoxyl sulphate into the urine, and upregulated the expression of renal organic anion transporter 1 (Oat1). Moreover, evaluation of rat kidney slices demonstrated that hyperoside promoted the uptake of PAH (p-aminohippurate, the Oat1 substrate), which was confirmed by transient over-expression of OAT1 in HEK-293T cells. Additionally, hyperoside upregulated the mRNA expression of Oat1 upstream regulators hepatocyte nuclear factor-1α (HNF-1α) and pregnane X receptor (PXR).These findings indicated hyperoside could protect against cisplatin-induced AKI by promoting indoxyl sulphate excretion through regulating the expression and function of Oat1, suggesting hyperoside may offer a potential tactic for cisplatin-induced AKI treatment.

Leukocyte-endothelial interaction in CKD

Chronic kidney disease (CKD) represents an independent risk factor for cardiovascular diseases (CVD). Accordingly, CKD patients show a substantial increased risk of cardiovascular mortality. Inflammation represents an important link between CKD and CVD. The interaction between endothelial cells and effector cells of the innate immune system plays a central role in the development and progression of inflammation. Vascular injury causes endothelial dysfunction, leading to augmented oxidative stress, increased expression of leukocyte adhesion molecules and chronic inflammation. CKD induces numerous metabolic changes, creating a uremic milieu resulting in the accumulation of various uremic toxins. These toxins lead to vascular injury, endothelial dysfunction and activation of the innate immune system. Recent studies describe CKD-dependent changes in monocytes that promote endothelial dysfunction and thus CKD progression and CKD-associated CVD. The NLR family pyrin domain containing 3-interleukin-1β-interleukin-6 (NLRP3-IL-1β-IL-6) signaling pathway plays a pivotal role in the development and progression of CVD and CKD alike. Several clinical trials are investigating targeted inhibition of this pathway indicating that anti-inflammatory therapeutic strategies may emerge as novel approaches in patients at high cardiovascular risk and nonresolving inflammation. CKD patients in particular would benefit from targeted anti-inflammatory therapy, since conventional therapeutic regimens have limited efficacy in this population.

Diabetic foot disease in subjects with End-stage renal Disease: A nationwide study over 14 years highlighting an emerging threat

AIMS

To disclose prevalence, demographic, foot characteristics as well as management and lower-extremity amputations (LEAs) of subjects with end-stage renal disease (ESRD) on diabetic foot diseases (DFDs).

METHODS

Data were derived from the Taiwan National Health Insurance Research Database between 2004 and 2017. DFDs were defined as ulcers, infections, or severe peripheral arterial diseases (PADs) in patients with type 2 diabetes. Clinical characteristics were analyzed between subjects with and without ESRD.

RESULTS

Subjects with ESRD have increased impacts on the DFD population either from annual prevalence (2.7 % to 10.42 %, P for trend < 0.001), or proportional representation in LEAs (7.91 % to 26.37 %, P < 0.001) over 14 years. The annual trends for major-LEAs rates have decreased in both subjects with and without ESRD (13.67 % to 5.82 % and 3.48 % to 1.47 %, both P < 0.001). Notably, the concomitant increase of endovascular treatments (EVTs) (7.09 % to 29.41 %, P < 0.001) was associated with the decrease of major-LEAs (P for interaction < 0.001) in subjects with ESRD.

CONCLUSIONS

As the annual prevalence of subjects with ESRD has increased 3.9-fold over years, they now account for more than 30% of annual major-LEA of the total DFD population. Interdisciplinary team approach and aggressive EVTs might reduce major-LEAs in these patients.

Impact of medium cut-off membranes on S100A12 and soluble receptor for advanced glycation end products

INTRODUCTION

Of the most remarkable molecules associated with atherosclerosis and the cardiovascular outcome are S100A12 (10,379.5 Da) and soluble receptor for advanced glycation end products (sRAGE-42,803 Da) in the hemodialysis (HD) population. We designed a study investigating the effects of the medium cut-off (MCO) dialyzers focusing on S100A12 and sRAGE in HD patients compared with low-flux and high-flux dialyzers.

METHODS

This single-site, prospective, observational study comprises age and sex-matched HD groups (low-flux, high-flux, and MCO). Blood samples were drawn at baseline (predialysis and postdialysis) and the sixth month (predialysis).

RESULTS

Groups had similar demographic features and laboratory parameters. Baseline S100A12 levels of the groups were similar [34.3 (±66.5), 30.9 (±42.7), and 40.6 (±29.6); p = 0.13]. Compared to their baseline, the sixth-month S100A12 levels were constant in low-flux and high-flux group and significantly lower in MCO group (p = 0.16, p = 0.33, and p = 0.004). Baseline sRAGE levels of the groups were similar at baseline [2.8 (±0.8), 2.7 (±0.6), and 2.6 (±0.7); p = 0.65], and the sixth-month [2.9 (±0.5), 2.4 (±0.7), and 2.4 (±0.8); p = 0.24]. sRAGE levels remained constant in all groups [p = 0.84, p = 0.13, and p = 0.39]. S100A12/sRAGE ratio at baseline and sixth month was constant in low-flux [22.3 (±63.7) and 18.1 (±24.8); p = 0.17] and high-flux groups [11.9 (±15.3) and 13.1 (±5.8); p = 0.26], the ratio decreased significantly in MCO group [16.5 (±11.6) to 7.8 (±5.5); p = 0.03].

CONCLUSION

Our study suggests that prolonged use of MCO dialyzers is associated with better S100A12 and sRAGE levels. Long-term studies with larger samples are needed to understand the effects of a better S100A12-sRAGE profile provided by MCO dialyzers on HD patients' cardiovascular outcomes.

Serum indoxyl sulphate and its relation to albumin and α1-acid glycoprotein as a potential biomarkers of maternal intestinal metabolism during pregnancy and postpartum

BACKGROUND

Serum indoxyl sulfate (IS) levels depend on the production of indole in the gut. The biological effects of IS in the vascular bed could be confirmed by changes in the levels of individual serum proteins during normal pregnancy and in the postpartum period as compared with non-pregnant controls. Albumin (Alb) and α1-acid glycoprotein (AGP, orosomucoid) are the most abundant serum carrier proteins with potential interrelationships with serum levels of IS.

METHODS

Serum levels of IS, Alb and AGP were measured in 84 pregnant women in the first, second and third trimester of pregnancy and in the postpartum period, as well as in non-pregnant controls (n = 20), using ultra-performance liquid chromatography (UPLC) coupled to mass spectrometry (IS), colorimetric assay (Alb) and immunoturbidimetric assay (AGP).

RESULTS

The postpartum serum levels [mg/L] of IS were lower (p = 0.027) than in the second trimester (mean±SD: 0.85±0.39 vs 0.58±0.32). There were no differences in the IS to ALB ratio calculated in the three trimesters of pregnancy, the postpartum period, and in the non-pregnant controls. The IS/AGP ratio increased from the first to the second trimester (p = 0.039), and decreased in the postpartum period (p<0.05), when it was lower than in the second and third trimester.

CONCLUSIONS

The variability of the serum IS/AGP ratio during pregnancy and in the postpartum period may reflect shared involvement in the regulation of their intravascular relationships. The link between serum levels of IS derived from the gut and AGP could serve a potential biomarkers of maternal intestinal metabolism during pregnancy and postpartum.

Regulation of pyroptosis in cardiovascular pathologies: Role of noncoding RNAs

Cardiovascular disease (CVD) is one of the most important diseases endangering human life. The pathogenesis of CVDs is complex. Pyroptosis, which differs from traditional apoptosis and necrosis, is characterized by cell swelling until membrane rupture, resulting in the release of cell contents and activation of a strong inflammatory response. Recent studies have revealed that inflammation and pyroptosis play important roles in the progression of CVDs. Noncoding RNAs (ncRNAs) are considered promising biomarkers and potential therapeutic targets for the diagnosis and treatment of various diseases, including CVDs. Growing evidence has revealed that ncRNAs can mediate the transcriptional or posttranscriptional regulation of pyroptosis-related genes by participating in the pyroptosis regulatory network. The role and molecular mechanism of pyroptosis-regulating ncRNAs in cardiovascular pathologies are attracting increasing attention. Here, we summarize research progress on pyroptosis and the role of ncRNAs, particularly microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in the regulation of pyroptosis in CVD pathologies. Identifying these disease-related ncRNAs is important for understanding the pathogenesis of CVDs and providing new targets and ideas for their prevention and treatment.

The immunoenhancement effects of starfish Asterias rollestoni polysaccharides in macrophages and cyclophosphamide-induced immunosuppression mouse models

The water-soluble polysaccharide, SF-2, obtained from starfish (Asterias rollestoni), belongs to the group of polysaccharides known as mannoglucan sulfate. It is composed of mannose as well as glucose and contains 13.85% SO₄^2-. We aimed to detect the immunoenhancement effects of SF-2 in macrophages and cyclophosphamide (CYP)-induced immunosuppression mouse models. RAW 264.7 macrophage cells were treated with SF-2 for different periods of time (0 h, 0.5 h, 1 h, 3 h, 6 h, and 9 h) and the results showed that SF-2 promoted the production of nitric oxide and up-regulated the levels of pro-inflammatory cytokines and related proteins, such as TNF-α, IL-1β, IL-6, COX-2, MMP-9, and iNOS in a time-dependent manner. In addition, SF-2 activated NLRP3 inflammasome and the MAPK/NF-κB signaling pathway, thus promoting its immunoenhancement effects. Moreover, we co-cultured the primary peritoneal macrophages with SF-2 for 6 h and found that SF-2 enhanced the expression of NLRP3 inflammasome and the release of cytokines. Furthermore, SF-2 significantly increased the body weight, spleen index, thymus index, and inflammatory cell counts in CYP-induced immunosuppression mouse models. These results indicate that SF-2 is a potential immunoenhancement mediator that acts by activating the NLRP3 inflammasome and MAPK/NF-κB pathway.