Association of elevated circulating monocyte-platelet aggregates with hypercoagulability in patients with nephrotic syndrome.

BACKGROUND: Hypercoagulability emerges as a central pathological feature and clinical complication in nephrotic syndrome. Increased platelet activation and aggregability are closely related to hypercoagulability in nephrotic syndrome. Monocyte-platelet aggregates (MPAs) have been proposed to represent a robust biomarker of platelet activation. The aim of this study was to investigate levels of the circulating MPAs and MPAs with the different monocyte subsets to evaluate the association of MPAs with hypercoagulability in nephrotic syndrome. METHODS: Thirty-two patients with nephrotic syndrome were enrolled. In addition, thirty-two healthy age and sex matched adult volunteers served as healthy controls. MPAs were identified by CD14 monocytes positive for CD41a platelets. The classical (CD14 + + CD16-, CM), the intermediate (CD14 + + CD16+, IM) and the non-classical (CD14 + CD16++, NCM) monocytes, as well as subset specific MPAs, were measured by flow cytometry. RESULTS: Patients with nephrotic syndrome showed a higher percentage of circulating MPAs as compared with healthy controls (p < 0.001). The percentages of MPAs with CM, IM, and NCM were higher than those of healthy controls (p = 0.012, p < 0.001 and p < 0.001, respectively). Circulating MPAs showed correlations with hypoalbuminemia (r=-0.85; p < 0.001), hypercholesterolemia (r = 0.54; p < 0.001), fibrinogen (r = 0.70; p < 0.001) and D-dimer (r = 0.37; p = 0.003), but not with hypertriglyceridemia in nephrotic syndrome. The AUC for the prediction of hypercoagulability in nephrotic syndrome using MPAs was 0.79 (95% CI 0.68-0.90, p < 0.001). The sensitivity of MPAs in predicting hypercoagulability was 0.71, and the specificity was 0.78. CONCLUSION: Increased MPAs were correlated with hypercoagulability in nephrotic syndrome. MPAs may serve as a potential biomarker for thrombophilic or hypercoagulable state and provide novel insight into the mechanisms of anticoagulation in nephrotic syndrome.

Quercetin improves diabetic kidney disease by inhibiting ferroptosis and regulating the Nrf2 in streptozotocin-induced diabetic rats.

Diabetic kidney disease (DKD) is a leading factor in end-stage renal disease. The complexity of its pathogenesis, combined with the limited treatment efficacy, necessitates deeper insights into potential causes. Studies suggest that ferroptosis-driven renal tubular damage contributes to DKD's progression, making its counteraction a potential therapeutic strategy. Quercetin, a flavonoid found in numerous fruits and vegetables, has demonstrated DKD mitigation in mouse models, though its protective mechanism remains ambiguous. In this study, we delved into quercetin's potential anti-ferroptotic properties, employing a DKD rat model and high glucose (HG)-treated renal tubular epithelial cell models. Our findings revealed that HG prompted unusual ferroptosis activation in renal tubular epithelial cells. However, quercetin counteracted this by inhibiting ferroptosis and activating NFE2-related factor 2 (Nrf2) expression in both DKD rats and HG-treated HK-2 cells, indicating its renal protective role. Further experiments, both in vivo and in vitro, validated that quercetin stimulates Nrf2. Thus, our research underscores quercetin's potential in DKD treatment by modulating the ferroptosis process via activating Nrf2 in a distinct DKD rat model, offering a fresh perspective on quercetin's protective mechanisms.

Epidemiology and risk factors for progression in Chinese patients with IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is one of the main causes of primary glomerulonephritis worldwide, and it is also the main primary disease leading to chronic kidney disease. The purpose of this study is to evaluate the epidemiology and risk factors for progression in Chinese patients with IgAN. METHODS: In this retrospective study, 246 patients with renal biopsy-proven IgAN were enrolled from January 2012 to June 2018. The patients' data were divided into two groups according to eGFR at the end of follow-up: a high-eGFR group (eGFR≥60ml/min) and a low-eGFR group (eGFR<60ml/min). RESULTS: At the end of the study, we identified 49 (19.92%) patients with low-eGFR from 246 IgAN patients. Renal function, represented by serum creatinine, urea nitrogen and cystatin-C, was significantly decreased in the low-eGFR group (P<0.001 for all) at the time of renal biopsy. Compared with the high-eGFR group, the age, mean arterial blood pressure (MAP), proteinuria, cholesterol, triglycerides and serum uric acid were significantly higher (P<0.05 for all). According to the Oxford evaluation, the proportion of S1-2 (59.2%) and T1-2 (65.3%) was significantly increased (P<0.001 for both) and the proportion that had a MEST-C score ≥3 was statistically increased in the low-eGFR group (83.7%, P=0.001). CONCLUSIONS: Male, MAP, haematuria, Scr, cholesterol, hemoglobin, Lee classification more than 3 and C1-2 are independent risk factors for low-eGFR in Chinese IgAN patients.

Plasma sMer, sAxl and GAS6 levels correlate with disease activity and severity in lupus nephritis.

OBJECTIVE: The purpose of this study is to determine whether TAM receptors and ligands associated with the activity and severity of lupus nephritis. METHODS: Clinical data were statistically analysed and studied in 122 SLE patients, diagnosed from 2013 to 2016 in First Hospital Affiliated to Harbin Medical University. Levels of TAM receptors and ligands in the plasma of 122 SLE patients were measured by ELISA. Renal biopsies were performed to confirm lupus nephritis (LN) by histopathology in 68 patients. The associations of TAM receptors and ligands with clinical and serological parameters were analysed in 68 LN patients. RESULTS: Amongst patients with SLE, those with LN had significantly higher plasma sMer, sAxl and GAS6 levels than those without renal involvement (P < 0.01 for all comparisons). Additional comparisons on the renal function-associated clinical parameters confirmed an indicative role of the sMer, sAXL and GAS6 levels in the cohort of patients with more severe nephritis. Patients with higher sMer, sAXL and GAS6 levels of LN patients tended to suffer from proliferative glomerulonephritis. The sAXL and GAS6 levels had a strong positive correlation with activity index (AI) in LN patients. Furthermore, there was a significant drop of the sMer, sAXL and GAS6 concentrations from the time of the biopsy to month t6, but no further decrease from months t6 to t12. CONCLUSIONS: These results suggest that plasma sMer, sAxl and GAS6 can be an additional clinical marker related to the disease activity and severity in LN.

Effect of the oral iron chelator deferiprone in diabetic nephropathy rats.

BACKGROUND: The aim of the present study was to investigate the effects of the iron chelator deferiprone in diabetic nephropathy (DN) rats and the mechanisms involved. METHODS: Thirty-two male Wistar rats (180-220 g, 6 weeks old) were randomly divided into a control group, a DN group and two DN groups treated with either 50 or 100 mg/kg per day deferiprone. The DN group was established by feeding of a high-carbohydrate-fat diet and injection of 35 mg/kg streptozotocin into the vena caudalis. The duration of deferiprone treatment was 20 weeks. Histopathological changes were detected by hematoxylin-eosin and Masson staining, as well as transmission electron microscopy. Levels of nuclear factor (NF)-κB, monocyte chemotactic protein (MCP)-1, matrix metalloproteinase (MMP)-9, tissue-specific inhibitor of metalloproteinase (TIMP)-1, cyclo-oxygenase (COX)-2, and nitrotyrosine were determined in kidney tissues using reverse transcription-polymerase chain reaction (RT-PCR), western blotting, and immunohistochemistry. RESULTS: Histopathological observations showed that deferiprone treatment alleviated inflammation infiltrates and collagenous fibrosis in DN rats. Results from RT-PCR and western blotting indicated that deferiprone inhibited the expression of NF-κB, MCP-1, COX-2, and nitrotyrosine, which were overexpressed in DN rats. Immunohistochemistry showed that the mechanism of deferiprone action may involve regulation of MMP-9 and TIMP-1. Decreased MMP-9 expression and increased TIMP-1 expression in DN rats were significantly promoted and inhibited by deferiprone, respectively. CONCLUSION: Iron chelation by oral deferiprone has a renoprotective effect in DN rats by relieving oxidative stress, inflammation, and fibrosis, which is related to the cytokines NF-κB, MCP-1, MMP-9, TIMP-1, COX-2, and nitrotyrosine.

Original Research: Atorvastatin prevents rat cardiomyocyte hypertrophy induced by parathyroid hormone 1-34 associated with the Ras-ERK signaling.

We investigated the effects of atorvastatin (Ator) on cardiomyocyte hypertrophy (CMH) induced by rat parathyroid hormone 1-34 (PTH1-34) and Ras-extracellular signal regulated protein kinases 1/2 (ERK1/2) signaling. Rat cardiomyocytes were randomly divided into seven groups: normal controls (NC), PTH1-34 (10(-7) mol/L), Ator (10(-5) mol/L), farnesyl transferase inhibitors-276 (FTI-276, 4 × 10(-5) mol/L), PTH1-34 + Ator, PTH1-34 + FTI-276 and PTH1-34 + Ator + mevalonic acid (MVA, 10(-4) mol/L). After treatment, the hypertrophic responses of cardiomyocytes were assessed by measuring cell diameter, detecting protein synthesis, and single-cell protein content. The concentrations of hypertrophic markers such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured by ELISA. Protein expressions of ERK1/2, p-ERK1/2 and Ras were detected by western blotting. The results showed that compared with the PTH1-34 group, cellular diameter, 3H-leucine incorporation, single-cell protein content, ANP and BNP concentration decreased by 12.07 µm, 1622 cpm/well, 84.34 pg, 7.13 ng/L and 20.04 µg/L, respectively, and the expressions of Ras and p-ERK1/2 were downregulated in PTH1-34 + Ator group (P < 0.05). Compared to the PTH1-34 + Ator group, the corresponding hypertrophic responses and hypertrophic markers increased by 4.95 µm, 750 cpm/well, 49.08 pg, 3.12 ng/L and 9.35 µg/L, respectively, and the expressions of Ras and p-ERK1/2 were upregulated in the PTH1-34 + Ator + MVA group (P < 0.05). In conclusion, Ator prevents neonatal rat CMH induced by PTH1-34 and Ras-ERK signaling may be involved in this process.

Co-Positivity for Anti-dsDNA, -Nucleosome and -Histone Antibodies in Lupus Nephritis Is Indicative of High Serum Levels and Severe Nephropathy.

OBJECTIVE: To characterize the significance of correlated autoantibodies in systemic lupus erythematosus (SLE) and its complication lupus nephritis (LN) in a large cohort of patients. METHODS: Clinical data were statistically analyzed in 1699 SLE patients with or without nephritis who were diagnosed and treated during 2002-2013 in the northeast region of China. Reactivity to a list of 16 autoantibodies was detected by the serum test Euroline ANA profile (IgG). Serum titers of the anti-nucleosome autoantibodies were measured by ELISA assays. Kidney biopsies were examined by pathologists. Immune complex deposition was identified by immunohistochemistry stain. RESULTS: Simultaneous positivity of anti-dsDNA, -nucleosome and -histone antibodies (3-pos) was prevalent in SLE patients with LN compared to Non-renal SLE patients (41% vs 11%, p< 0.001). Significant correlations were found between any two of the above three anti-nucleosome antibodies in LN patients. In comparison to non-3-pos cohorts, 3-pos patients with LN had significantly higher serum levels of the three antibodies and more active disease; was associated with type IV disease; suffered from more severe renal damages; received more intensive treatment and had worse disease outcome. The serum levels of these three autoantibodies in 3-pos LN patients were significantly decreased when they underwent clinical recovery. CONCLUSIONS: Simultaneous reactivity to anti-dsDNA, -nucleosome and -histone antibodies by Euroline ANA profile (IgG) may indicate severe nephropathy in patients with SLE.

Relationship between hypoalbuminemia, hyperlipidemia and renal severity in patients with lupus nephritis: a prospective study.

AIM OF THE STUDY: The purpose is to evaluate the relationship between hypoalbuminemia, hyperlipidemia, nephrotic and renal severity in patients with lupus nephritis. MATERIAL AND METHODS: Autoantibodies and serological parameters were measured and analyzed in 429 patients with lupus nephritis in a single centre. RESULTS: The prevalence for anti-dsDNA, anti-nucleosome and anti-histone was higher in the nephrotic syndrome (NS) patients than that in non-NS patients (p < 0.0001 for all comparisons). The NS patients had a higher proportion of diffuse proliferative renal lesions (69.05%) and membranous lesions (68.00%). Serum total cholesterol and albumin levels were associated with activity and severity of renal disease. The levels of proteinuria and serum albumin were positively correlated with activity and chronicity index (p < 0.001 for all correlations). The incidence of a poor renal outcome (p = 0.0461) in the NS patients was significantly increased. On the other hand, the remission rate (p = 0.0002) was significantly reduced and recurrence rate (p = 0.0027) was significantly increased in NS patients. CONCLUSIONS: This paper highlights that nephrotic-range proteinuria, elevated total cholesterol level and decreased serum albumin levels may reflect the activity and severity of renal damage in SLE patients.

Iron chelator alleviates tubulointerstitial fibrosis in diabetic nephropathy rats by inhibiting the expression of tenascinC and other correlation factors.

Tubulointerstitial fibrosis is the final common pathway to diabetic nephropathy. However, only a few drugs are responsible for this pathologic process. We investigated the possible effect of deferiprone (iron chelator) treatment on experimental diabetic nephropathy (DN) rats, as well as the mechanisms involved in this process. Diabetic nephropathy was induced in rats by feeding on high-carbohydrate-fat food and injecting streptozotocin. After 20 weeks of deferiprone treatment, tubulointerstitial morphology was detected by staining with hematoxylin-eosin and Masson's trichrome. Tubulointerstitial fibrosis was measured using the point-counting technique. Biochemical parameters including fasting glucose, insulin resistance (IR), serum iron, ferritin, transferrin saturation (TS), and urinary albumin/creatinine ratio (UA/C) were detected in diabetic nephropathy models. Semiquantitative RT-PCR, western blot, and immunohistochemistry were utilized for evaluating mRNA and protein levels of tenascin C, fibronectin 1 (Fn1), TGF-ß1, and collagen IV in nephridial tissue, respectively. Malonialdehyde (MDA) and superoxide dismutase (SOD) were determined by pyrogallol and thiobarbituric acid method. Tubulointerstitial fibrosis was significantly ameliorated after deferiprone treatment, and both mRNA and protein expressions of profibrotic factors were inhibited in treatment groups. Meanwhile, high levels of serum iron, ferritin, TS, and UA/C were observed in DN rats. These factors were down-regulated by deferiprone treatment. Furthermore, deferiprone effectively relieved serum IR and regulated oxidative stress process. Our results demonstrated the anti-fibrosis potential and renoprotective effects of deferiprone for diabetic nephropathy, and this process was partially mediated by tenascin C blocking.

Simultaneous positivity for anti-DNA, anti-nucleosome and anti-histone antibodies is a marker for more severe lupus nephritis.

OBJECTIVE: The purpose of this study is to examine autoantibody profile of systemic lupus erythematosus (SLE) patients with lupus nephritis (LN) and to establish the correlation between the antibody reactivity and disease activity of LN. METHODS: Autoantibodies and serological parameters were measured and analyzed in 589 SLE patients. The associations of the co-positivity of anti-dsDNA, -nucleosome and -histone antibodies (3-pos) with clinical, serological and outcome parameters were analyzed. RESULTS: At the study entry, the prevalence for anti-dsDNA (61.52 % vs. 34.11 %, P < 0.0001), anti-nucleosome (56.09 % vs. 37.21 %, P = 0.0002) and anti-histone (49.35 % vs. 33.33 %, P = 0.0013) antibodies in patients with LN were significantly higher than that in patients without LN. Patients with 3-pos had a higher proportion of proliferative renal lesions (class III + IV). The incidence of a poor renal outcome (7.14 % vs. 2.52 %, P = 0.0174) in LN patients with 3-pos was significantly higher than those without 3-pos. Moreover, the rate of remission (73.63 % vs. 82.37 %, P = 0.0245) was significantly reduced and recurrence increased (58.90 % vs. 23.44 %, P < 0.0001) in 3-pos patients as compared to that in non 3-pos within the LN group. CONCLUSION: Our data indicate a strong association between the 3-pos and renal disease activities, especially proliferative glomerulonephritis. The ability of 3-pos to predict renal flares may lead to major additional benefits in the follow-up of these patients.

[Atorvastatin attenuates parathyroid hormone 1-34 induced cardiomyocytes hypertrophy through downregulating K-Ras-ERK1/2 pathway].

OBJECTIVE: To investigate the effects of atorvastatin on parathyroid hormone 1-34 (PTH1-34) induced neonatal rat cardiomyocytes hypertrophy and on the expression changes of small GTP-binding protein (K-Ras) and extracellular signal regulated protein kinases 1/2 (ERK1/2). METHODS: Neonatal rat cardiomyocytes hypertrophy was established with 10(-7) mol/L rPTH1-34 in the presence or absence of 10(-5) mol/L atorvastatin or 10(-4) mol/L mevalonic acid (MVA). Cardiomyocyte diameter was measured by Motic Images Advanced 3.0 software, the synthetic rate of protein in cardiomyocytes was determined by (3)H-leucine incorporation and single-cell protein content was measured by BCA. The concentration of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were determined by ELISA. Protein expression of ERK1/2, p-ERK1/2 and K-Ras was detected by Western blot. RESULTS: Compared to PTH1-34 group, cellular diameter was decreased 12.07 µm, (3)H-leucine incorporation decreased 1622 cpm/well and single-cell protein content decreased 84.34 pg, ANP or BNP concentration reduced 7.13 µg/L or 20.04 µg/L, protein expression of K-Ras, ERK1/2 or p-ERK1/2 downregulated 0.81, 0.19 and 1.44 fold, respectively, in PTH1-34 plus atrovastatin co-treated cardiomyocytes (all P < 0.05). Compared to PTH1-34 plus atrovastatin co-treated group, cardiomyocyte diameter increased 4.95 µm, (3)H-leucine incorporation increased 750 cpm/well and single-cell protein content increased 49.08 pg, ANP or BNP increased 3.12 µg/L or 9.35 µg/L and protein expression of K-Ras, ERK1/2 or p-ERK1/2 upregulated 0.52, 0.06 and 1.19 fold (all P < 0.05) in MVA, PTH1-34 and atrovastatin co-treated cardiomyocytes. CONCLUSIONS: Atrovastatin attenuates PTH1-34 induced neonatal rat cardiomyocytes hypertrophy through downregulating K-Ras and ERK1/2 pathway.

The sphingosine-1-phosphate receptor agonist FTY720 prevents the development of anti-glomerular basement membrane glomerulonephritis.

The sphingosine-1-phosphate (S1P) agonist FTY720 prolongs the survival of organ allograft and attenuates autoimmune-mediated injury in experimental models. Most cases of glomerulonephritis (GN) in human appear to be immunologically initiated. In this study, we evaluated the potential therapeutic role of FTY720 in GN via a mouse anti-glomerular basement membrane (GBM) model. Mice were immunized with rabbit IgG in complete Freund's adjuvant (CFA) followed by an intravenous injection of a rabbit anti-mouse GBM serum. Disease and immune responses were assessed on day 14. Mice were treated with FTY720 (0.3 or 3 mg/kg) and prednisone (10 mg/kg) from days 0 to 14. The S1P modulator reduced proteinuria, serum creatinine, crescent formation and serum IgG level. The expressions of splenic S1P receptor and renal Th-1 cytokine were also inhibited at the transcription stage. Treatment with FTY720 increased splenocyte production of protective Th2 cytokine IL-4 and promoted the apoptosis of splenic CD4+ T cells in the animal models, which suggests that FTY720 played a protective role at the induction stage of GN by inhibiting mRNA expressions of splenic S1P receptor 1, S1P receptor 2, and S1P receptor 5.

[Expression and significance of CD80/CD86 in renal tissue of lupus nephritis].

OBJECTIVE: To measure the expression of CD80 and CD86 in renal tissue of lupus nephritis (LN) and explore its mechanism in the development of LN. METHODS: Forty-nine patients with active LN and 9 patients with minor glomerular abnormalities tissues as controls were studied. The expression of CD80 and CD86 in renal tissues was detected by immunohistochemical methods. RESULTS: CD86 was expressed extensively in glomerulus, periglomerular area, tubular epithelial cells and peritubular interstitium, while CD80 was expressed only in tubular epithelial cells and peritubular interstitium. Moreover, the percentage of CD80+ and CD86+ cells in tubular epithelial cells and peritubular interstitium showed a tendency to increase with tubulointerstitial damage. The expression of CD80 and CD86 in renal tissue correlated with the systemic lupus erythematosus (SLE) disease activity index score, the degree of proteinuria, creatinine clearance and anti-dsDNA antibody. CONCLUSIONS: This study shows that increased CD80 and CD86 expression with the progression of tubulointerstitial lesion might play an important role in the development of lupus nephropathy, and the tubulointerstitial expression of CD80 and CD86 could potentially serve as a surrogate marker of SLE disease activity. The co-stimulatory molecules CD80 and CD86 might play an important role in the pathogenesis of LN.