Fujun Lin

Increased CD45RA+ FoxP3(low) regulatory T cells with impaired suppressive function in patients with systemic lupus erythematosus.

Background The role of naturally occurring regulatory T cells (Treg) in the control of the development of systemic lupus erythematosus (SLE) has not been well defined. Therefore, we dissect the phenotypically heterogeneous CD4+FoxP3+ T cells into subpopulations during the dynamic SLE development. Methodlogy/Principal Findings To evaluate the proliferative and suppressive capacities of different CD4+ T cell subgroups between active SLE patients and healthy donors, we employed CD45RA and CD25 as surface markers and carboxyfluorescein diacetatesuccinimidyl ester (CFSE) dilution assay. In addition, multiplex cytokines expression in active SLE patients was assessed using Luminex assay. Here, we showed a significant increase in the frequency of CD45RA+FoxP3low naive Treg cells (nTreg cells) and CD45RA−FoxP3low (non-Treg) cells in patients with active SLE. In active SLE patients, the increased proportions of CD45RA+FoxP3low nTreg cells were positively correlated with the disease based on SLE disease activity index (SLEDAI) and the status of serum anti-dsDNA antibodies. We found that the surface marker combination of CD25+CD45RA+ can be used to defined CD45RA+FoxP3low nTreg cells for functional assays, wherein nTreg cells from active SLE patients demonstrated defective suppression function. A significant correlation was observed between inflammatory cytokines, such as IL-6, IL-12 and TNFα, and the frequency of nTreg cells. Furthermore, the CD45RA+FoxP3low nTreg cell subset increased when cultured with SLE serum compared to healthy donor serum, suggesting that the elevated inflammatory cytokines of SLE serum may promote nTreg cell proliferation/expansion. Conclusions/Significance Our results indicate that impaired numbers of functional CD45RA+FoxP3low naive Treg cell and CD45RA−FoxP3low non-suppressive T cell subsets in inflammatory conditions may contribute to SLE development. Therefore, analysis of subsets of FoxP3+ T cells, using a combination of FoxP3, CD25 and CD45RA, rather than whole FoxP3+ T cells, will help us to better understand the pathogenesis of SLE and may lead to the development of new therapeutic strategies.

Whole exome sequencing reveals novel COL4A3 and COL4A4 mutations and resolves diagnosis in Chinese families with kidney disease

BackgroundCollagen IV-related nephropathies, including thin basement membrane nephropathy and Alport Syndrome (AS), are caused by defects in the genes COL4A3, COL4A4 and COL4A5. Diagnosis of these conditions can be hindered by variable penetrance and the presence of non-specific clinical or pathological features.MethodsThree families with unexplained inherited kidney disease were recruited from Shanghai, China. Whole exome sequencing (WES) was performed in the index case from each family and co-segregation of candidate pathogenic mutations was tested by Sanger sequencing.ResultsWe identified COL4A4 missense variants [c.G2636A (p.Gly879Glu) and c.C4715T (p.Pro1572Leu)] in the 21-year-old male proband from family 1, who had been diagnosed with mesangial proliferative nephropathy at age 14. COL4A4 c.G2636A, a novel variant, co-segregated with renal disease among maternal relatives. COL4A4 c.C4715T has previously been associated with autosomal recessive AS and was inherited from his clinically unaffected father. In family 2, a novel COL4A3 missense mutation c.G2290A (p.Gly997Glu) was identified in a 45-year-old male diagnosed with focal segmental glomerulosclerosis and was present in all his affected family members, who exhibited disease ranging from isolated microscopic hematuria to end stage renal disease (ESRD). In family 3, ESRD occurred in both male and females who were found to harbor a known AS-causing COL4A5 donor splice site mutation (c.687 + 1G > A). None of these variants were detected among 100 healthy Chinese individuals.ConclusionWES identified 2 novel and 2 known pathogenic COL4A3/COL4A4/COL4A5 mutations in 3 families with previously unexplained inherited kidney disease. These findings highlight the clinical range of collagen IV-related nephropathies and resolved diagnostic confusion arising from atypical or incomplete clinical/histological findings, allowing appropriate counselling and treatment advice to be given.

A novel COL4A1 frameshift mutation in familial kidney disease: the importance of the C-terminal NC1 domain of type IV collagen

Background Hereditary microscopic haematuria often segregates with mutations of COL4A3, COL4A4 or COL4A5 but in half of families a gene is not identified. We investigated a Cypriot family with autosomal dominant microscopic haematuria with renal failure and kidney cysts. Methods We used genome-wide linkage analysis, whole exome sequencing and cosegregation analyses. Results We identified a novel frameshift mutation, c.4611_4612insG:p.T1537fs, in exon 49 of COL4A1. This mutation predicts truncation of the protein with disruption of the C-terminal part of the NC1 domain. We confirmed its presence in 20 family members, 17 with confirmed haematuria, 5 of whom also had stage 4 or 5 chronic kidney disease. Eleven family members exhibited kidney cysts (55% of those with the mutation), but muscle cramps or cerebral aneurysms were not observed and serum creatine kinase was normal in all individuals tested. Conclusions Missense mutations of COL4A1 that encode the CB3 [IV] segment of the triple helical domain (exons 24 and 25) are associated with HANAC syndrome (hereditary angiopathy, nephropathy, aneurysms and cramps). Missense mutations of COL4A1 that disrupt the NC1 domain are associated with antenatal cerebral haemorrhage and porencephaly, but not kidney disease. Our findings extend the spectrum of COL4A1 mutations linked with renal disease and demonstrate that the highly conserved C-terminal part of the NC1 domain of the α1 chain of type IV collagen is important in the integrity of glomerular basement membrane in humans.

Serum phosphorus is related to left ventricular remodeling independent of renal function in hospitalized patients with chronic kidney disease

BACKGROUND Increasing evidence indicated that phosphorus emerged as an important cardiovascular risk factor in patients with chronic kidney disease (CKD). The fact that serum phosphorus was closely linked to vascular and valvar calcification may account for one important reason. However, left ventricular remodeling may also serve as another potential mechanism of the cardiac toxicity of phosphorus. In the present study, we evaluated the association of serum phosphorus with left ventricular remodeling. METHODS We investigated consecutive hospitalized patients with pre-dialysis CKD, who did not have symptomatic heart failure or take any phosphorus binder or calcitriol medications. Transthoracic echocardiography was applied to assess their left ventricular remodeling indices, both structural and functional. RESULTS The 296 study subjects (mean age 56.4years) included 169 (57.1%) men, 203 (68.6%) hypertensive patients. In addition to gender, systolic blood pressure, and estimated glomerular filtration rate, serum phosphorus was an independent determinant of left ventricular mass index (LVMI, P=0.001). Similarly, serum phosphorus was also a determinant of left ventricular end diastolic dimension (P=0.0003), but not of relative wall thickness. In multivariate logistic analyses, serum phosphorus was significantly and independently associated with the prevalence of left ventricular hypertrophy (LVH, odds ratio [OR] 2.38 for each 1mmol/L increase, 95% CI 1.20-4.75, P=0.01). Moreover, the association was only confirmatory in eccentric LVH (OR 3.01, 95% CI 1.43-6.32, P=0.003) but not in concentric LVH (1.38, 95% CI, 0.54-3.49, P=0.50). CONCLUSION Serum phosphorus was significantly and independently associated with LVMI and the prevalence of eccentric LVH in hospitalized patients with CKD.

Micro RNA-155 inhibitor as a potential therapeutic strategy for the treatment of acute kidney injury (AKI): a nanomedicine perspective

In this study, we have prepared miR-155 inhibitor-loaded liposome vesicles for the effective treatment of acute kidney injury. The efficacy of liposomal miR-155 inhibitor in the expression of miR-155, mortality in animals, the expression of TNF-α-IL6, and the expression of SOCS1–STAT1 were evaluated. The loading of miR-155 inhibitor into liposomes conferred the much needed colloidal stability and efficient delivery to the renal tissues. The study clearly shows that miR-I-LV significantly decreases the expression of miR-155 in kidneys compared to LPS. Administration of miR-I-LV remarkably reduced the pathological concerns of the kidneys with a marked decrease in inflammatory cell infiltration. Scrambled miR-155 did not have any effect on the expression of these markers; however miR-I-LV showed a remarkable ability to decrease the expression of TNF-α and IL-6 in kidney tissues indicating an ability to treat acute kidney infections. Overall, administration of miR-155 inhibitor effectively alleviated LPS-induced kidney injury by significantly suppressing TNF-α and IL-6 in kidney tissue and by remarkably increasing the expression of mRNA of SOCS1 and STAT1. The present results suggest that miR-155 inhibitor could be used in an effective targeting strategy for the treatment of acute kidney injury (AKI).

Impact of hemoglobin variability on cardiovascular mortality in maintenance hemodialysis patients

PurposeAlthough the association between anemia and cardiovascular mortality in hemodialysis patients is well established, whether hemoglobin variability (Hgb-Var) affects the prognosis remains unclear. We aimed to evaluate the association between Hgb-Var and cardiovascular mortality in Chinese hemodialysis patients.MethodsThis retrospective study included 252 patients starting hemodialysis in Xin Hua Hospital between January 2009 and December 2015. Patients were divided into three tertiles based on Hgb-Var, as reflected by SD Hgbmean, SD Hgbrange, and Hgbdeflection during a 12-month evaluation period after hemodialysis initiation. Left ventricular ejection fraction (EF) and left ventricular mass index (LVMI) were evaluated by echocardiography. Information on cardiovascular deaths occurred by December 2017 was collected. Multivariate Cox regression models were constructed to evaluate the association between Hgb-Var and cardiovascular mortality.ResultsA total of 75 deaths and 52 cardiovascular deaths occurred during the 47-month follow-up (range 29.5–70). Under multivariate regression, the subgroup with the highest Hgb-Var had a higher risk of cardiovascular mortality after adjusting for relevant factors (HR vs. lowest SD Hgbmean: 9.15, 95% CI 2.82, 29.693, P < 0.0001; HR vs. lowest SD Hgbrange: 3.81, 95% CI 1.40, 10.38, P = 0.005). Per 1 SD of Hgbmean and Hgbrange elevations were both related to a 10% increase in the cardiovascular mortality risk. Baseline EF% and LVMI did not differ across the Hgb-Var subgroups. EF% upon the last patient visit to the clinic was lower in the subgroup with the highest SD Hgbmean (P = 0.02).ConclusionsHigh Hgb-Var is an independent risk factor for cardiovascular mortality in hemodialysis patients and might influence the cardiac function.

THSD7A-associated membranous nephropathy in a patient with neurofibromatosis type 1

Target antigens in idiopathic membranous nephropathy (MN) include the phospholipase A2 receptor (PLA2R), and in some cases, the thrombospondin type 1 domain-containing 7A (THSD7A). A notable phenomenon is the high rate of cancer (reported to be as high as 20%) in patients with THSD7A-associated MN. Neurofibromatosis type 1 (NF1) is an autosomal dominant disease caused by NF1 gene mutation, and clinically characterized by multiple cutaneous neurofibromas and café-au-lait spots. In this article, we report a patient with NF1 who developed THSD7A-associated MN when the NF1 skin lesions deteriorated. The patient, a 62-year-old male, was referred to us for nephrotic syndrome for 6 months. Physical examination revealed multiple cutaneous nodules throughout the entire body, and the patient noted recent increase in the numbers of these skin lesions. Cutaneous nodules excisional biopsy suggested NF1 and Sanger sequencing using genomic DNA extracted from peripheral blood revealed a previously reported heterozygous frameshift NF1 mutation (c.1541_1542delAG, p. Gln514fs). Renal biopsy revealed MN and immunohistochemistry (IHC) showed enhanced staining of THSD7A as well as PLA2R along the glomerular basement membrane whereas the serum level of THSD7A and PLA2R were both within normal range. The neurofibroma tissues were positive for THSD7A but not for PLA2R on IHC. The patient did not respond to 6-month treatment with glucocorticosteroid and cyclophosphamide. In this exceptional case, strong positive staining of THSD7A in both skin and renal biopsy samples, together with the temporal association between nephrotic syndrome and skin lesions and lack of treatment response, suggested the possibility that MN could be the result of immune response to THSD7A in NF1. This report may improve understanding of the mechanistic link between MN and cancer.