Huali Wang

Binding capacity and pathophysiological effects of IgA1 from patients with IgA nephropathy on human glomerular mesangial cells

IgA deposition in glomerular mesangium and the interaction with mesangial cells may well be the final common pathway to IgA nephropathy (IgAN). Altered hinge‐region O‐glycosylation of IgA1 from patients with IgAN may predispose to mesangial deposition and activation of the mesangial cell (MC) by IgA1, via a novel IgA1 receptor, and may be a key event in the pathogensis of IgAN. The aim of this study was to investigate the binding capacity and biological effects of IgA1, from both patients with IgAN and healthy controls, on human mesangial cells (HMC). Serum IgA1 was isolated with jacalin affinity chromatography, heated to aggregated form (aIgA1) and labelled with 125I. Binding capacity of aIgA1 in vitro to cultured primary HMC was evaluated by a radioligand binding assay and the specificity of binding was determined by a competitive inhibition assay. Intracellular calcium release was studied by confocal analysis and phosphorylation of extracellular signal‐regulated kinase (ERK) was determined by Western blot analysis. Change of cell cycles was demonstrated by flow cytometry and HMC proliferation was evaluated by direct cell count. Expression of TGF‐β mRNA and production of supernatant fibronectin were tested by RT‐PCR and indirect competitive ELISA, respectively. aIgA1 from both the patients with IgAN and normal controls bound to HMC in a dose‐dependent, saturable manner, and was saturated at approximately 500 pmoles per 0·5 ml of aIgA1. aIgA1 from patients with IgAN, however, bound to HMC at a higher speed and Scatchard analysis revealed a Kd of (8·89 ± 2·1) × 10−8mversus (4·3 ± 1·2) × 10−7m for aIgA1 from healthy controls (P = 0·026).The binding was specific because it was only inhibited by unlabelled Mono‐IgA1 (mIgA1) and not by serum albumin or IgG. aIgA1 from patients with IgAN could induce release of intracellular calcium, phosphorylation of ERK, DNA synthesis, proliferation of HMC, expression of TGF‐βmRNA and secretion of fibronectin in HMC in a similar time‐dependent manner as aIgA1 from healthy controls, but the effects were much stronger and the durations were much longer (P < 0·05, respectively). We conclude that aIgA1 from patients with IgAN has a higher binding capacity to HMC and stronger biological effects than aIgA1 from healthy controls. This suggests that direct interaction between IgA1 and HMC and subsequential pathophysiological responses may play an important role in the pathogenesis for IgAN.

Neutrophil extracellular traps can activate alternative complement pathways

The interaction between neutrophils and activation of alternative complement pathway plays a pivotal role in the pathogenesis of anti‐neutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV). ANCAs activate primed neutrophils to release neutrophil extracellular traps (NETs), which have recently gathered increasing attention in the development of AAV. The relationship between NETs and alternative complement pathway has not been elucidated. The current study aimed to investigate the relationship between NETs and alternative complement pathway. Detection of components of alternative complement pathway on NETs in vitro was assessed by immunostain and confocal microscopy. Complement deposition on NETs were detected after incubation with magnesium salt ethyleneglycol tetraacetic acid (Mg‐EGTA)‐treated human serum. After incubation of serum with supernatants enriched in ANCA‐induced NETs, levels of complement components in supernatants were measured by enzyme‐linked immunosorbent assay (ELISA). Complement factor B (Bb) and properdin deposited on NETs in vitro. The deposition of C3b and C5b‐9 on NETs incubated with heat‐inactivated normal human serum (Hi‐NHS) or EGTA‐treated Hi‐NHS (Mg‐EGTA‐Hi‐NHS) were significantly less than that on NETs incubated with NHS or EGTA‐treated NHS (Mg‐EGTA‐NHS). NETs induced by ANCA could activate the alternative complement cascade in the serum. In the presence of EGTA, C3a, C5a and SC5b‐9 concentration decreased from 800·42 ± 244·81 ng/ml, 7·68 ± 1·50 ng/ml, 382·15 ± 159·75 ng/ml in the supernatants enriched in ANCA induced NETs to 479·07 ± 156·2 ng/ml, 4·86 ± 1·26 ng/ml, 212·65 ± 44·40 ng/ml in the supernatants of DNase I‐degraded NETs (P < 0·001, P = 0·008, P < 0·001, respectively). NETs could activate the alternative complement pathway, and might thus participate in the pathogenesis of AAV.

The Level of Serum Brain-Derived Neurotrophic Factor Is Associated With the Therapeutic Efficacy of Modified Electroconvulsive Therapy in Chinese Patients With Depression

Objective: To investigate the association between the level of serum brain-derived neurotrophic factor (sBDNF) and the therapeutic efficacy of modified electroconvulsive therapy (MECT) in Chinese patients with depressive disorder. Methods: Twenty-eight patients with depressive episode and 28 healthy subjects were recruited in the current study. The sBDNF level was examined in all subjects before treatment and after a 2-week treatment with MECT in patients with depression. The severity of depression was measured according to the 17-item Hamilton Rating Scale for Depression in patients with depression. Results: The severity of depression reduced significantly in patients with depression after a 2-week treatment with MECT (31.39 [SD, 4.65] vs 8.14 [5.52], P < 0.001). Serum BDNF level in patients with depression was significantly lower than that of the control group before treatment (5.66 [SD, 2.07] vs 9.17 [SD, 1.26] ng/mL, P < 0.001), then increased remarkably to the level of control subjects 2 weeks after MECT (7.90 [SD, 3.42] ng/mL). The increasing rate of sBDNF in patients with depression was significantly correlated with the decreasing rate of the total 17-item Hamilton Rating Scale for Depression score (r = 0.532, P = 0.004) and cluster scores of cognitive dysfunction (P = 0.018) and retardation (P = 0.048). Conclusion: The change in sBDNF is associated with the therapeutic efficacy of MECT in Chinese patients with depression.

Anti-endothelial cell antibodies (AECA) in patients with propylthiouracil (PTU)-induced ANCA positive vasculitis are associated with disease activity.

Increasing evidence has demonstrated that propylthiouracil (PTU) could induce ANCA positive vasculitis. However, our previous work has suggested that only one‐fifth of the PTU‐induced ANCA positive patients had clinical vasculitis and so the mechanism is not clear. Anti‐endothelial cell antibodies (AECA) have been implicated in the pathogenesis of various vasculitides, including primary ANCA positive systemic vasculitis. The purpose of this study is to investigate the prevalence of AECA and their possible role in the pathogenesis of patients with PTU‐induced ANCA positive vasculitis. Sera from 11 patients with PTU‐induced ANCA positive vasculitis at both active and quiescent phases, and sera from 10 patients with PTU‐induced ANCA but without clinical vasculitis, were studied. Sera from 30 healthy blood donors were collected as normal controls. Soluble proteins from 1% Triton‐100 extracted in vitro cultured human umbilical vein endothelial cells were used as antigens and an immunoblotting technique was performed to determine the presence of AECA, and their specific target antigens were identified. In patients with PTU‐induced ANCA positive vasculitis, 10 of the 11 patients in an active phase of disease were serum IgG‐AECA positive and six protein bands of endothelial antigens could be blotted (61 kD, 69 kD, 77 kD, 85 kD, 91 kD and 97 kD). However, in the quiescent phase, seven of the 10 positive sera turned negative. None of the ANCA positive but vasculitis negative patients or normal controls were AECA positive. In conclusion, AECA could be found in sera from patients with PTU‐induced ANCA positive vasculitis and were associated more closely with vasculitic disease activity.

Anti-myeloperoxidase antibodies in sera from patients with propylthiouracil-induced vasculitis might recognize restricted epitopes on myeloperoxidase molecule

Myeloperoxidase (MPO) is one of the major target antigens of antineutrophil cytoplasmic antibodies (ANCA) in primary systemic vasculitis. It is known that propylthiouracil (PTU) could induce MPO–ANCA‐positive vasculitis. The production of anti‐MPO antibodies in patients with PTU‐induced vasculitis may be different from that in patients with primary microscopic polyangiitis (MPA). One possible reason for this may be differences in epitope recognition. The aim of this study is to compare the epitopes of antibodies to MPO in sera from patients with PTU‐induced vasculitis (n = 10) and MPA (n = 10). The sera were collected and used to inhibit monoclonal antibodies against human MPO (3D8 and 6B9) and affinity purified, horseradish peroxidase conjugated human anti‐MPO antibodies (Pab1‐HRP, Pab2‐HRP) in a competitive inhibition enzyme‐linked immunosorbent assay (ELISA) system using soluble human MPO as solid phase ligand. The Pab1‐HRP and Pab2‐HRP were affinity purified from plasma exchanges of a patient with PTU‐induced vasculitis and a patient with MPA, respectively. The inhibition rates were evaluated and compared between the PTU and primary MPA groups. In the PTU group all 10 sera could inhibit 3D8: the average inhibition rate was 44·7% ± 5·0%; 9/10 sera could inhibit 6B9: the average inhibition rate was 35·6% ± 6·0%. However, in the MPA group all 10 sera could inhibit 3D8 and 6B9; the average inhibition rates were 68·4% ± 16·1% (P < 0·01) and 62·2% ± 17·2% (P < 0·01), respectively. Sera in both the PTU and MPA groups could inhibit Pab1‐HRP and the inhibition rates were 81·4% ± 9·4%versus 86·6% ± 17·2% (P > 0·05). However, the average inhibition rate for Pab2‐HRP in the MPA group was significantly higher than that in the PTU group (76·3% ± 7·8%versus 58·9% ± 15·5%, P < 0·01). We conclude that anti‐MPO antibodies from patients with PTU‐induced vasculitis and from patients with primary MPA could recognize more than one epitope on the native MPO molecule. Although the epitopes overlapped between the two groups, the epitopes of anti‐MPO antibodies from patients with PTU‐induced vasculitis might be more restricted.

Activity of α2,6‐Sialyltransferase and its Gene Expression in Peripheral B Lymphocytes in Patients with IgA Nephropathy

It is known that aberrant sialylation of IgA1 is involved in the pathogenesis of IgA nephropathy (IgAN). We hypothesize that aberrant sialylation of serum IgA1 may result from changes in the activity of α2,6‐sialyltransferase (α2,6‐ST) or expression of its coding gene ST6GALNAC2 in peripheral B lymphocytes. Sixty patients with IgAN and 20 healthy controls were enrolled. Peripheral B lymphocytes were isolated by CD‐19‐positive magnetic beads. The expression level of ST6GALNAC2 was quantitatively analysed by real‐time reverse‐transcriptase polymerase chain reaction (PCR). Serum IgA1 and sialylation levels were detected by enzyme‐linked immunosorbent assay (ELISA) and specific lectin‐binding ELISA. Activity of α2,6‐ST was measured by specific lectin‐binding ELISA. Expression of ST6GALNAC2 in B peripheral lymphocytes was significantly lower in patients with IgAN than that in normal controls (3.7 ± 2.2 versus 6.3 ± 2.3, P = 0.016); α2,6‐ST activity in B lymphocytes was correlated positively with the level of α2,6‐sialic acid in serum IgA1 in patients (n = 42) and controls (n = 12) (r = 0.37, P = 0.007). However, α2,6‐ST activity did not differ between patients with IgAN and controls (1.19 ± 1.43 versus 1.06 ± 1.17, P > 0.05). These data suggested that reduced sialylation of serum IgA1 may result from decreased expression of ST6GALNAC2. The factors affecting activity of α2,6‐ST in the sialylation of IgA1 need to be further investigated.

The influence of education on Chinese version of Montreal cognitive assessment in detecting amnesic mild cognitive impairment among older people in a Beijing rural community.

To assess the influence of education on the performance of Chinese version of Montreal cognitive assessment (C-MoCA) in relation to the mini-mental state examination (MMSE) in detecting amnesic mild cognitive impairment (aMCI) among rural-dwelling older people C-MoCA and MMSE was administered and diagnostic interviews were conducted among community-dwelling elderly in two villages in Beijing. The performance of C-MoCA and MMSE in detecting aMCI was evaluated by the area under the ROC curve (AUC). Effect size of education on variations in C-MoCA scores was estimated with general linear model. Among 172 study participants (24 cases of aMCI and 148 normal controls), the AUC of C-MoCA was 0.72 (95% CI = 0.62–0.81, cutoff = 20/21), compared to AUC of MMSE of 0.74 (95% CI = 0.64–0.84, cutoff = 26/27). The performance of both C-MoCA and MMSE was especially poorer among those with low (0–6 years) education. After controlling for gender and age, education (η 2 = 0.204) had a surpassing effect over aMCI diagnosis (η 2 = 0.052) on variations in C-MoCA scores. Among rural older people, the MoCA showed modest accuracy and was no better than MMSE in detecting aMCI, especially in those with low education, due to the overwhelming effect of education relative to aMCI diagnosis on variations in C-MoCA performance.

Differential binding characteristics of native monomeric and polymeric immunoglobulin A1 (IgA1) on human mesangial cells and the influence of in vitro deglycosylation of IgA1 molecules

Recent studies had demonstrated that serum and mesangial immunoglobulin A1 (IgA1) in patients with IgA nephropathy (IgAN) were polymeric and deglycosylated. The current study was to investigate the binding characteristics of monomeric and polymeric normal human IgA1 on mesangial cells and the influence of in vitro deglycosylation of IgA1 molecules. The normal human IgA1 was desialylated and degalactosylated with specific enzymes, respectively. The monomeric IgA1 (mIgA1) and polymeric IgA1 (pIgA1) were separated by Sephacryl S‐300 chromatography. The binding capacities of the mIgA1 and pIgA1 to primary human mesangial cells (HMC) were evaluated by classical radioligand assay. Both the native mIgA1 and pIgA1 could bind to HMC in a dose‐dependent and saturable manner. The maximal binding capacity of the native pIgA1 were significantly higher than that of the native mIgA1 (P < 0·05). However, the affinity of the native mIgA1 was almost 100 times higher than that of the native pIgA1. After deglycosylation, binding of the two deglycosylated mIgA1 to HMC could not be detected. However, the maximal binding capacities of the two deglycosylated pIgA1 to HMC were increased significantly compared with that of native pIgA1. The affinity of the two deglycosylated pIgA1 was similar to that of native pIgA1 (P > 0·05). The current study suggests differential binding characteristics of native monomeric and polymeric IgA1 on mesangial cells. Glycosylation of IgA1 molecules could significantly affect the binding of IgA1 on HMC.

The expression of Toll-like receptors 2, 4 and 9 in kidneys of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis

Increasing evidence suggested that Toll‐like receptors (TLRs) were critically involved in immune responses of anti‐neutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV). The current study aimed to investigate the expression of TLR‐2, TLR‐4 and TLR‐9 in kidneys of patients with ANCA‐associated vasculitis. Renal biopsy specimens were collected from 24 patients with AAV. The expression of TLR‐2, TLR‐4 and TLR‐9 in kidneys was detected by immunohistochemistry. Double immunofluorescence staining was performed to detect the expression of TLRs on various kinds of cells. In renal specimens, immunohistochemical examination revealed that expression of TLR‐2 and TLR‐4 could be detected in the glomeruli of AAV patients, while TLR‐2 and TLR‐4 were scarcely detected in the glomeruli of normal controls. Double immunofluorescence staining of TLR‐2, TLR‐4 and CD31 indicated that TLR‐4 and TLR‐2 were expressed on endothelial cells in the glomeruli. In the tubulointerstitial compartment, expression of TLR‐2, TLR‐4 and TLR‐9 could be detected in both AAV patients and normal controls. The mean optical density of TLR‐2 and TLR‐4 in the tubulointerstitial compartment in AAV patients were significantly higher than that in normal controls. Among AAV patients, correlation analysis showed that the mean optical density of TLR‐4 in the glomeruli correlated inversely with the initial serum creatinine, the proportion of total crescents and the proportion of cellular crescents in renal specimens (r = −0·419, P = 0·041; r = −0·506, P = 0·012; r = −0·505, P = 0·012, respectively). The expression of TLR‐2 and TLR‐4 was dysregulated in kidneys of AAV patients. The expression of TLR‐4 in glomeruli was associated with the severity of renal injury.

Caregivers in China: knowledge of mild cognitive impairment.

This study aimed to examine the experience and knowledge of mild cognitive impairment (MCI) among Chinese family caregivers of individuals with MCI. The sample was recruited from memory clinics in Zhongnan Hospital in Wuhan, China. In-depth semi-structured interviews were used. Thirteen family members of individuals diagnosed with MCI participated in the study. Data analysis revealed three themes: 1) initial recognition of cognitive decline; 2) experience of the diagnosis of MCI; 3) perception of cognitive decline as a normal part of aging. While family members recognized the serious consequences of memory loss (e.g. getting lost), they would typically not take their family members to see a doctor until something specific triggered their access to the medical care system. The Chinese traditional perception of dementia as part of normal aging may serve to lessen the stigma of individuals with MCI, while the term “laonian chidai” which literally translates to “stupid, demented elderly” may exacerbate the stigma associated with individuals with MCI. It is suggested that family members’ worries may be relieved by improving their access to accurate knowledge of the disease, community-based and institutional care services, and culturally appropriately words are needed for MCI.