Whole-exome sequencing screening for candidate genes and variants associated with primary sporadic keratoconus in Chinese patients.

The pathogenesis of keratoconus (KC) is complex, and genetic factors play an important role. The purpose of this study was to screen and analyse candidate genes and variants in Chinese patients with primary sporadic KC. Whole-exome sequencing (WES) was performed to identify candidate genes and variants in 105 unrelated Chinese patients with primary sporadic KC. Through a series of screening processes, 54 candidate variants in 26 KC candidate genes were identified in 53 KC patients (53/105, 50.5%). These 54 candidate variants included 10 previously identified variants in 9 KC candidate genes and 44 novel variants in 20 KC candidate genes. The previously identified variants occurred in 25.7% (27/105) of patients. Of these, 4 variants (COL6A5, c.5014T > G; CAST, c.1814G > A; ZNF469, c.946G > A; and MPDZ, c.3836A > G) were identified for the first time in Chinese KC patients. The novel variants occurred in 33.3% (35/105) of patients. Of the 26 screened KC candidate genes, 11 KC candidate genes (CAT, COL12A1, FLG, HKDC1, HSPG2, PLOD1, ITGA2, TFAP2B, USH2A, WNT10A, and COL6A5) were found to be potentially pathogenic in Chinese KC patients for the first time. Gene Ontology (GO) biological process (BP) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed on the 26 KC candidate genes using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). The results showed that the KC candidate genes were significantly enriched in biological processes such as collagen fibril organization and extracellular matrix (ECM) organization and in ECM-receptor interaction and protein digestion and absorption pathways. The results further expand the spectrum of KC candidate variants and provide a basis for further KC gene studies.

Potential Protective Role of TRPM7 and Involvement of PKC/ERK Pathway in Blue Light-Induced Apoptosis in Retinal Pigment Epithelium Cells in Vitro.

PURPOSE: Blue light triggers apoptosis of retinal pigment epithelium (RPE) cells and causes retinal damage. The aim of this study was to elucidate the protective role of transient receptor potential melastatin 7 (TRPM7) in photodamaged RPE cells. METHODS: RPE cells were isolated from Sprague-Dawley (SD) rats and exposed to varying intensities of blue light (500-5000 lux) in vitro. Cell proliferation and metabolic activity were respectively assessed by bromodeoxyuridine (BrdU) incorporation and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays. Real-time polymerase chain reaction (RT-PCR) and western blotting were used to analyze the TRPM7, protein kinase C (PKC), extracellular signal-regulated kinase (ERK) and Bcl2-associated x/B-cell lymphoma 2 (Bax/Bcl-2) messenger RNA (mRNA) and protein expression levels. The cells were transfected with TRPM7 small interfering RNA (siRNA) or transduced with TRPM7-overexpressing lentiviruses and cultured with or without the pigment epithelium-derived factor (PEDF). RESULTS: Blue light inhibited the proliferation and metabolic activity of RPE cells in an intensity-dependent manner when compared to nonirradiated controls (P < 0.05). Compared to the control, photodamaged RPE cells showed decreased levels of TRPM7, PKC, ERK, and Bax, and an increase in Bcl-2 levels (P < 0.01). Forced expression of TRPM7 partially rescued the proliferative capacity of RPE cells (P < 0.01) and restored the levels of TRPM7, PKC, ERK, and Bax (P < 0.01), whereas TRPM7 knockdown had the opposite effects (P < 0.01). TRPM7 and PEDF synergistically alleviated the damaging effects of blue light. CONCLUSIONS: Blue light triggers apoptosis of RPE cells, and its deleterious effects can be partially attenuated by the synergistic action of TRPM7 and PEDF via the PKC/ERK signaling pathway.

Ultrasensitive and selective fluorescent sensor for cysteine and application to drug analysis and bioimaging.

A fluorescent sensor based on coumarin-maleimide conjugate was developed for efficient discrimination of Cys from Hcy and GSH in both organic and aqueous solution. Addition of Cys to the non-fluorescent sensor solution in DMF induced bright blue fluorescence and enhanced the fluorescence intensity by 320-fold while other amino acids and biothiols (Gly, Hcy, GSH, Glu, Val, Tyr, Arg, Trp, Lys, His, Leu, Phe, Asp and Met) did not bring about remarked change. The sensor responds to Cys extremely rapidly. If Cys was added to the sensor solution, the fluorescence intensity increased by 170-fold immediately and attained the maximum value in 5 min. A linear relationship was observed between Cys concentration within 2-20 µM and the fluorescence intensity of the sensor solution. The detection limit of the sensor toward Cys is as low as 4.7 nM. The sensor is also effective for specific detection of Cys in aqueous (DMF/H2O = 9:1, v/v) solution. Practical application of the sensor to drug analysis and bioimaging of living Hela cells has been verified. Possible sensing mechanism of the sensor toward Cys has been proposed.

Coumarin Thiourea-Based Fluorescent Turn-on Hg2+ Probe That Can Be Utilized in a Broad pH Range 1-11.

A novel coumarin-thiourea conjugate was synthesized facilely. It served as a fluorescent turn-on chemosensor for selective detection of Hg2+ ion over other common competitive metal ions including Li+, Na+, K+, Ag+, Cu2+, Fe2+, Zn2+, Co2+, Ni2+, Mn2+, Sr2+, Ca2+, Mg2+, Al3+, Cr3+ and Fe3+ ions based on the Hg2+-promoted desulfurization and cyclization reactions. Addition of Hg2+ ion to the sensor solution in 2:8 EtOH/H2O induced a hypsochromic shift of the UV-Vis absorption band from 360 nm to 340 nm accompanying distinct enhancement in the absorption intensity while addition of other metal ions failed to bring about substantial change in the absorption spectra. Addition of Hg2+ to the sensor solution also caused marked increase in the fluorescence emission intensity and most common competitive metal ions did not interfere with the selective sensing of Hg2+ ion by the sensor. The detection limit of Hg2+ ion by the probe was calculated to be 1.46 × 10-7 M and the probe could be utilized for selective detection of Hg2+ ion by fluorescence turn-on mode over a broad pH range of 1-11.

[Influence of HSCT Preconditioning on ADAMTS-13 Activity and vWF level and Its Clinical Significance].

OBJECTIVE: To explore the influence of precondintioning on ADAMTS-13 activity and vWF level, and its clinical significance by measuring the alterations of ADAMTS-13 activity and vWF antigen levels before and after preconditioning of hematopoietic stem cell transplantation (HSCT) in the patients. METHOD: A total of 113 patients received HSCT in the First Hospital affiliated to Soochow University were investigated, 20 healthy volunteers were used as the control. The ADAMTS-13 activity and vWF antigen level were measured by FRETS-vWF73 and ELISA respectively. Modified BU/CY, TBI/CY or BEAM were used as preconditioning regimen. RESULTS: (1) out of all the patients enrolled in this study, 8 patients were diagnosed as thrombotic disorders, and 49 patients were with occurence of acute graft-versus-host disease (aGVHD); (2) comparing with the control group, the ADAMTS-13 activity were lower and vWF antigen was higher in the patients after preconditioning (P < 0.01). Among all the patients, 69 (59.3%) cases showed the decrease of ADAMTS-13 activity after preconditioning, including 9 patients with more than 60% (9/113, 8.0%) decrease, in the meantime, the average plasma vWF antigen level of these 69 patients was significantly increased after preconditioning (P < 0.05); (3) the plasma ADAMTS-13 activity in 8 patients with thrombotic complications decreased after preconditioning, and there was significant difference in comparision with that of patients without thrombotic complication (P < 0.01). The patients with decrease of ADAMTS-13 activity more than 60% accounted for 37.5% (3/8), at the same time, the the level of vWF antigen increased (P < 0.01); (4) The medium level of ADAMTS-13 activity was dropped in 49 patients with aGVHD after preconditoning, but there was no abvious difference in comparision with that of patients without aGVHD. Among them 25 patients were with significant drop actvity of ADAMTS-13 at that time when aGVHD occurred (P < 0.01). Out of them, the patients with drop more than 60% before preconditioning accounted for 60% (2/35). The logistic regression analyse showed that the drop of ADAMTS-13 activity more than 60% before preconditioning was the risk factor for occurence of thrombosis at the later stage (P < 0.01), but the drop of ADAMTS-13 activity after preconditioning did not was the risk factor for occurence of aGVHD. CONCLUSION: The decrease of ADAMTS-13 activity after preconditioning of HSCT confirmed to be lower than that befor preconditioning of HSCT, and the level of vWF antigen after preconditioning of HSCT could be higher than that before precondifioning, especially in patients with thrombosis. The decrease of ADAMTS-13 activity after preconditioning has been found to be mone than 60%, then this decrease can be considered as an independent risk factor for later thrombogenesis, but the decrease of ADAMTS-13 after precoditioning activity did not associate with occurence of aGVHD, so the decrease of ADAMTS-13 activity can be used as an important predictor of thrombosis after HSCT.

Experimental study on a room temperature urea-SCR of NO over activated carbon fibre-supported CeO2-CuO.

In order to establish a desirable method for NO reduction, selective catalytic reduction (SCR) of NO by urea-CeO2/ACF and urea-CeO2-CuO/ACF was carried out at room temperature. The experimental results showed that 10% urea-9% CeO2/ACF could yield the highest NO conversion of 85% among the series of urea-CeO2/ACF prepared. When urea-CeO2-CuO/ACF was compared with urea-CeO2/ACF, it achieved higher NO conversion to a certain degree with the addition of CuO, which was attributed to the synergistic effect between cerium and copper. The effect of the mass ratio of CeO2 and CuO was also observed. The desirable mass ratio of CeO2 and CuO was 1:1, which yielded about 90% NO conversion when ACF was loaded with 10% urea. Furthermore, the influence of O2 concentration and NO concentration was also observed. In this study, NO conversion increased with increasing O2 concentration. In addition, some samples were further characterized by BET, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared methods.

[Detection of tissue factor-positive microparticles and its clinical significance in the haemostatic disorder].

Objective of this study was to detect the level of tissue factor-positive microparticles (TF(+)MP) by flow cytometry (FCM) and to analyze its clinical significance in the haemostatic disorder. TF(+) MP was detected by FCM using antibody CD142-PE in 25 cases of acute promyelocytic leukemia (APL), 20 cases of hemostatic diseases and 20 healthy adults as controls. The differences of TF(+) MP between various groups were determined. The results showed that the level of TF(+) MP in the patients with thrombotic complications was significantly higher than that in the healthy adults (P < 0.05). The TF(+) MP level was higher in the patient with APL than that in the healthy adults, especially in course before therapy (P < 0.01), but the difference was not statistically significant in the patient with APL after therapy and the healthy adults. Among these patient with APL, the level of TF(+) MP in the 18 patients who complicated with disseminated intravascular coagulation (DIC) was also higher than that in the healthy adults (P < 0.05), but the level of TF(+) MP in the other 7 patients who did not complicate with DIC was similar before and after treatment. It is concluded that the method of TF(+) MP detection by FCM is feasible and simple, it is useful for the diagnosis of thrombotic disorder, and helps evaluation for the prognosis of APL patient.

[Expression of vWF73 and VWF114 fragments of von Willebrand factor A2 domain and their utilization in detecting ADAMTS13 activity].

OBJECTIVE: To construct the expression vectors of vWF73 and vWF114 fragments of von Willebrand factor (vWF) A2 domain, and to express glutathione S-transferase (GST) fusion proteins in E. coli, and to explore their values in measuring ADAMTS13 activity as substrates. METHODS: The DNA fragments encoding vWF73 and vWF114 were generated using PCR and separately cloned into pGEX-6P-1, a Schistosoma japonicum GST fusion expression vector. The expression of GST-vWF73-H and GST-vWF114-H was induced in liquid culture, followed by purification with Ni-NTA agarose column. The cleavage of two GST fusion proteins by recombinant ADAMTS13 (rADAMTS13) or plasma from normal individuals and thrombotic thrombocytopenic purpura (TTP) patients were identified by Western blot. Based on an enzyme-linked immunosorbent assay (ELISA) with anti-GST and anti-His monoclonal antibodies, GST-vWF73-H and GST-vWF114-H were used to measure plasma ADAMTS13 activity as substrates. RESULTS: Two small molecular substrates of ADAMTS13, GST-vWF73-H and GST-vWF114-H, are expressed and purified, which could be specifically cleaved by rADAMTS13 or plasma from healthy individuals, but not by plasma from congenital or idiopathic TTP patients. An ELISA assay was established to detect plasma ADAMTS13 activity using GST-vWF73-H and GST-vWF114-H as substrates. CONCLUSIONS: Two GST fusion proteins in vWF A2 domain, vWF73 and vWF114, were expressed effectively using a prokaryotic expression system and could be used to detect ADAMTS13 activity as substrates.

Alterations of hemostatic parameters in the early development of allogeneic hematopoietic stem cell transplantation-related complications.

Thrombotic events are common and potentially fatal complications in patients receiving hematopoietic stem cell transplantation (HSCT). Early diagnosis is crucial but remains controversial. In this study, we investigated the early alterations of hemostatic parameters in allogeneic HSCT recipients and determined their potential diagnostic values in transplantation-related thrombotic complications and other post-HSCT events. Results from 107 patients with allogeneic HSCT showed higher levels of plasma plasminogen activator inhibitor-1 (PAI-1), fibrinogen, and tissue-plasminogen activator (t-PA) and a lower level of plasma protein C after transplantation. No change was found for prothrombin time, antithrombin III, D: -dimer, and activated partial thromboplastin time following HSCT. Transplantation-related complications (TRCs) in HSCT patients were defined as thrombotic (n=8), acute graft-versus-host disease (aGVHD, n=45), and infectious (n=38). All patients with TRCs, especially the patients with thrombotic complications, presented significant increases in the mean and maximum levels of PAI-1 during the observation period. Similarly, a high maximum t-PA level was found in the thrombotic group. In contrast, apparent lower levels of mean and minimum protein C were observed in the TRC patients, especially in the aGVHD group. Therefore, the hemostatic imbalance in the early phase of HSCT, reflecting prothrombotic state and endothelial injury due to the conditioning therapy or TRCs, might be useful in the differential diagnosis of the thrombotic complication from other TRCs.