Circulating monocyte-platelet aggregates with different monocyte subsets and their association with disease severity in chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is usually considered an immune inflammatory disease. Interaction between platelets and monocytes is associated with immune inflammation. Cross-talk between platelets and monocytes is reflected by formation monocyte-platelet aggregates (MPAs). This study aims to test MPAs and MPAs with the different monocyte subsets to evaluate their association with disease severity in CKD. METHODS: Forty-four hospitalized patients with CKD and twenty healthy volunteers were enrolled. The proportion of MPAs and MPAs with the different monocyte subsets were tested by flow cytometry. RESULTS: The proportion of circulating MPAs in all patients with CKD were significantly higher than those of healthy controls (p<0.001). A higher proportion of MPAs with classical monocytes (CM) was found in CKD4-5 patients (p=0.007), while another higher proportion of MPAs with non-classical monocytes (NCM) was found CKD2-3 patients (p<0.001). The proportion of MPAs with intermediate monocytes (IM) in CKD 4-5 group was significantly higher in comparison to CKD2-3 group and healthy controls (p<0.001). Circulating MPAs were found to be correlated with serum creatinine (r=0.538, p<0.001) and eGFR (r=-0.864, p<0.001). The AUC for MPAs with IM was 0.942 (95% CI 0.890-0.994, p<0.001). CONCLUSIONS: Study results highlight the interplay between platelets and inflammatory monocytes in CKD. There are alterations in circulating MPAs and MPAs with the different monocyte subsets in CKD patients compared to controls which change with CKD severity. The MPAs may have an important role in the development of CKD or as a predictive marker for monitoring disease severity.

Elevated Soluble Podoplanin Associates with Hypercoagulability in Patients with Nephrotic Syndrome.

Podoplanin (PDPN) promotes platelet aggregation and activation by interacting with C-type lectin-like receptor 2(CLEC-2) on platelets. The interaction between the upregulated PDPN and platelet CLEC-2 stimulates venous thrombosis. PDPN was identified as a risk factor for coagulation and thrombosis in inflammatory processes. Hypercoagulability is defined as the tendency to develop thrombosis according to fibrinogen and/or D dimer levels. Nephrotic syndrome is also considered to be a hypercoagulable state. The aim of this study is to investigate the association of soluble PDPN/CLEC-2 with hypercoagulability in nephrotic syndrome. Thirty-five patients with nephrotic syndrome and twenty-seven healthy volunteers were enrolled. PDPN, CLEC-2 and GPVI concentrations were tested by enzyme-linked immunosorbent assay (ELISA). Patients with nephrotic syndrome showed higher serum levels of PDPN and GPVI in comparison to healthy controls (P < .001, P = .001). PDPN levels in patients with nephrotic syndrome were significantly correlated with GPVI (r = 0.311; P = .025), hypoalbuminemia (r = -0.735; P < .001), hypercholesterolemia (r = 0.665; P < .001), hypertriglyceridemia (r = 0.618; P < .001), fibrinogen (r = 0.606; P < .001) and D-dimer (r = 0.524; P < .001). Area under the curve (AUC) for the prediction of hypercoagulability in nephrotic syndrome using PDPN was 0.886 (95% CI 0.804-0.967, P < .001). Cut-off value for the risk probability was 5.88 ng/ml. The sensitivity of PDPN in predicting hypercoagulability was 0.806, and the specificity was 0.846. When serum PDPN was >5.88 ng/ml, the risk of hypercoagulability was significantly increased in nephrotic syndrome (OR = 22.79, 95% CI 5.92-87.69, P < .001). In conclusion, soluble PDPN levels were correlated with hypercoagulability in nephrotic syndrome. PDPN has the better predictive value of hypercoagulability in nephrotic syndrome as well as was a reliable indicator of hypercoagulable state.

KMUP-1 regulates the vascular calcification in chronic renal failure by mediating NO/cGMP/PKG signaling pathway.

OBJECTIVE: To explore the potential mechanism of KMUP-1 in the vascular calcification of chronic renal failure (CRF) through mediating NO/cGMP/PKG pathway, and provide novel insights into the CRF treatment. METHODS: CRF rats were treated by KMUP-1 with/without L-NNA (a NOS inhibitor) and then performed by ELISA, alizarin red staining, Von Kossa staining, Masson's trichrome, Sirius red staining and CD3 immunohistochemical staining. Simultaneously, vascular smooth muscle cells (VSMCs) were collected from rats to confirm the effect of KMUP-1 on vascular calcification in vitro via NO/cGMP/PKG pathway. Besides, protein and mRNA expressions were determined via Western blotting and qRT-PCR, respectively. RESULTS: CRF rats were elevated in 24-h urine protein, blood urea nitrogen (BUN), serum creatinine, Cys-C levels and inflammatory cytokines. Besides, CRF rats also showed increased calcium content and ALP level with up-regulated mRNA of osteogenic differentiation-related markers. Furthermore, the up-regulated expressions of eNOS and PKG, as well as down-regulated levels of NOx and cGMP were also found in CRF rats. However, renal failure and vascular calcification of CRF were improved significantly by KMUP-1 treatment via activation of NO/cGMP/PKG pathway. Moreover, KMUP-1 treatment attenuated calcified VSMCs, accompanied by the decreases in the calcified nodules, level of calcium and activity of ALP. In addition, either L-NNA treatment for CRF rats or the calcified VSMCs could antagonize the improving effect of KMUP-1. CONCLUSION: KMUP-1 can improve the renal function and vascular calcification in CRF rats at least in part by activating NO/cGMP/PKG pathway.