Neuropathy optic glaucomatosa induced by systemic hypertension through activation endothelin-1 signaling pathway in central retinal artery in rats

AIM: To evaluate effect of hypertension on retinal ganglion cell (RGC) apoptosis, intraocular pressure (IOP), and the activation of endothelin-1 (ET-1) signaling pathway in central retinal artery (CRA) in rats. METHODS: The experimental study was performed on 20 male Sprague Dawley rats that were divided into control group, and hypertension groups. The hypertension was induced by subcutaneous deoxycorticoacetate (DOCA) 10 mg/kg twice a week and administered 0.9% NaCl solution daily for 2, 6, and 10wk. Blood pressure (BP) was measured using animal BP analyzer. IOP was measured by handheld tonometry. Retinal tissue preparations by paraffin blocks were made after enucleation. The expression of ET-1, eNOS, ET-1 receptor A (ETRA), ET-1 receptor B (ETRB), and phosphorylated myosin light chain kinase (MLCK), and caldesmon (CaD) in CRA and RGC apoptosis were evaluated through immunofluorescent staining method then observed using laser scanning confocal microscopy. RESULTS: BP significantly increased in all of the hypertension groups compared to control (P=0.001). Peak IOP elevation (7.78±4.14 mm Hg) and RGC apoptosis (576.15±33.28 Au) occurred on 2wk of hypertension. ET-1 expression (1238.6±55.1 Au) and eNOS expression (2814.2±70.7 Au) were found highest in 2wk of hypertension, although the ratio of ET-1/eNOS decreased since 2wk. ETRA reached peak expression in 10wk of hypertension (1219.4±6.3 Au), while ETRB significantly increased only in 2 weeks group (1069.2±9.6 Au). The highest MLCK expression (1190.09±58.32 Au), CaD (1670.28±18.36 Au) were also found in 2wk of hypertension. CONCLUSION: Hypertension effects to activation of ET-1 signaling pathway significantly in CRA, elevation of IOP, and RGC apoptosis. The highest value was achieved at 2wk, which is the development phase of hypertension.     

Effect of GSH and niacin combination on protein oxidation, ER stress, glycation and aggregation in HLE cells under high glucose condition

AIM: To evaluate the effects of reduced glutathione (GSH) and niacin combination on protein oxidative stress, endoplasmic reticulum (ER) stress, glycation, and aggregation of the αβ crystalline in human lens epithelial (HLE) cells treated with high glucose levels. METHODS: HLE cells were cultured and exposed to 25 mmol/L glucose to promote high glucose conditions. Groups of cells were co-treated with three different combinations of dosages: 10 μmol/L GSH+25 μmol/L niacin (P1), 30 μmol/L GSH+25 μmol/L niacin (P2), and 100 μmol/L GSH+25 μmol/L niacin (P3). After 72h incubation, protein carbonyl content (PCC) and glucose reactive protein (GRP78) content were assessed using ELISA examinations. After two-week incubation, advanced glycation end products (AGEs) were also assessed and the expression of αβ crystalline was measured using Western blot examination. RESULTS: PCC and GRP78 levels in the co-treated groups were not significantly reduced compared to control (P>0.05). In contrast, there was a significant decrease of the AGEs levels in all groups co-treated with GSH and niacin when compared with the control group (P<0.05). In addition, the αβ crystalline expression increased after high dose glucose administration, but decreased in all groups co-treated with GSH and combinations of GSH and niacin. CONCLUSION: Combinations of GSH and niacin inhibit the aggregation of proteins and prevent glycation in hyperglycemic HLE cells. This study shows that this combination may play an active role in preventing diabetic cataract mainly from the AGEs pathway.     

Impact of modified gelatin on valvular microtissues

A significant challenge in the field of tissue engineering is the biofabrication of three‐dimensional (3D) functional tissues with direct applications in organ‐on‐a‐chip systems and future organ engineering. Multicellular valvular microtissues can be used as building blocks for the formation of larger scale valvular macrotissues. Yet, for the controlled biofabrication of 3D macrotissues with predefined complex shapes, directed assembly of microtissues through bioprinting is needed. This study aimed to investigate if modified gelatin is an instructive material for valvular microtissues. Valvular microtissues were encapsulated in modified gelatin hydrogels and cross‐linked in the presence of a photoinitiator (Irgacure 2959 or VA‐086). Hydrogel properties were determined, and valvular interstitial cell functions like phenotype, proliferation, migration, mRNA expression of extracellular matrix (ECM) molecules, ECM deposition, and tissue fusion were characterized by histochemical stainings and RT‐qPCR. Encapsulated microtissues remained viable, produced heart valve‐related ECM components, and remained in a quiescent state. However, encapsulation induced some changes in ECM formation and gene expression. Encapsulated microtissues showed lower remodeling capacity and increased expression levels of Col I/V, elastin, hyaluronan, biglycan, decorin, and Sox9 compared with nonencapsulated microtissues. Furthermore, this study demonstrated that proliferation, migration, and tissue fusion was more pronounced in softer gels. In general, we evidenced that modified gelatin is an instructive material for physiologically relevant valvular microtissues and provided a proof of concept for the formation of larger valvular tissue by assembling microtissues at random in soft gels.     

外用脂肪干细胞培养上清液对二氧化碳点阵激光焕肤术后伤口愈合的影响

目的探讨局部外用脂肪干细胞培养上清液在二氧化碳点阵激光焕肤术后伤口愈合过程中的作用。方法9名受试者的双侧前臂内侧分别接受二氧化碳点阵激光治疗。随机选择受试者一侧前臂激光治疗处外敷脂肪干细胞培养上清液,另一侧则外敷DMEM细胞培养基。分别在上述处理后第1,4,7,14,21天检测受试部位经皮水分丢失、皮肤颜色及皮肤弹性。结果经过局部外用脂肪干细胞培养上清液一侧的红斑指数、黑色素指数和经皮水分丢失均显著低于对照侧。而皮肤弹性与对照侧差异无统计学意义。结论局部应用脂肪干细胞培养上清液是促进二氧化碳点阵激光焕肤术后伤口愈合和减少不良影响的一种有效方法。     

Characterization of the miRNA profile in UVB-irradiated normal human keratinocytes

The aim of this study was to assess the effects of ultraviolet B (UVB) irradiation on microRNA (miRNA) expression in normal human keratinocytes. Global miRNA expression profiles of primary cultures of normal human keratinocytes 4 and 24 h postirradiation were studied using miRNA microarray with further confirmation by real-time PCR. We found that upon 30 or 60 mJ/cm(2) of UVB radiation, the expression of 44 miRNAs was up- or downregulated more than twofold compared with non-irradiated keratinocytes. MiRNAs were either up- or downregulated after 4 h and then either returned to normal levels or remained affected after 24 h, resulting in four distinct patterns of miRNA expression change. It appears that acute exposure of keratinocytes to UVB radiation results in several specific patterns of miRNA response.     

Simultaneous ultraviolet and first near-infrared window absorption of luminescent carbon dots/PVA composite film

Liquid Carbon Dots (CDs) were successfully synthesized by hydrothermal method using urea and citric acid as raw materials. TEM images confirmed that the CDs have a spherical shape with a homogeneous distribution. The as-prepared liquid CDs could absorb ultraviolet (UV) and first near infra-red (NIR) window simultaneously. However, the photoluminescence (PL) of the liquid CDs was damaged by their quenching effect. To overcome this issue, the liquid CDs were dispersed in poly(vinyl) alcohol (PVA) to fabricate the composite film. Herein, the dual-peak absorption properties of the CDs/PVA composite films were investigated for the first time. The composite films could maintain the simultaneous UV and first NIR window absorption property even after being preheated up to 200 °C, implying that the structure of CDs was well retained during the transition from the liquid to films. Daylight treatment for seven days produced minimum changes in the UV-vis and PL spectra, which indicates that the CDs/PVA film has more stable optical properties than the liquid CDs.

The simultaneous UV and first NIR absorption of the CDs/PVA composite could be maintained up to 200 °C, with minimum PL changes.     

MiR-23a regulates DNA damage repair and apoptosis in UVB-irradiated HaCaT cells

BackgroundMiRNAs remain at a constant level under physiological conditions. However, how the expression of miRNAs is regulated and what are the roles of miRNAs in response to UVB damage to skin cells is still not fully understood. In our preliminary study, we observed that miR-23a was upregulated following a treatment with a DNA repair agent and UVB exposure.ObjectiveTo investigate the regulation and function of miR-23a in response to UVB-induced injury in human keratinocyte cell line (HaCaT) cells.MethodsThe changes in expression of miR-23a after UVB irradiation of HaCaT cells were measured by qRT-PCR. The level of miR-23a expression was also modulated by transfecting with a miR-23a mimic or an inhibitor. Cell viability was assessed by the CCK-8 assay. Immunofluorescence staining and Southwestern dot blotting were used to detect the levels of cyclobutane pyrimidine dimers (CPDs). Flow cytometry, Hoechst staining, and measurements of caspase-3 activity were employed to measure the incidence of apoptosis. The mRNA and protein expression levels of genes related to DNA reparation and apoptosis, such as topoisomerase-1, caspase-7, and STK4, were analyzed by qRT-PCR and Western blotting, respectively.ResultsMiR-23a expression was remarkably up-regulated at 4 h and 24 h after the UVB irradiation of HaCaT cells. UVB-induced apoptosis was increased by down-regulation of miR-23a. UVB-induced removal of CPDs was accelerated by miR-23a up-regulation and delayed by miR-23a down-regulation. Forced over-expression of miR-23a decreased the expression of UVB-induced topoisomerase-1\caspase7\STK4 at both the mRNA and protein levels, and these effects were reversed by down-regulation of miR-23a.ConclusionThe protection of HaCaT cells against UVB damage is afforded by miR-23a through regulation of topoisomerase-1\caspase7\STK4, and this miRNA may be a novel therapeutic target in skin diseases related to UVB radiation.     

Complex formation constant of ferric ion with Gly,Pro-Hyp and Gly-Pro-Hyp

The complexes of protein hydrolysates with iron ions may provide one solution for treating iron deficiency because they can work as iron absorption promoters. The chelating ability of some protein hydrolyzates is the key for their iron absorption promotion. Collagen is the most abundant protein in the nature, and collagen peptides are reported to have the ability to promote iron absorption. Collagen''s basic tri-peptide unit, i.e., glycine–proline–hydroxyproline (Gly-Pro-Hyp) and its digestion products, glycine (Gly) and proline–hydroxyproline (Pro-Hyp), have been studied against the ferric metal ion. The complexation abilities were determined potentiometrically at three different temperatures of 25 °C, 37 °C, and 40 °C. The ionic strength was maintained using 0.15 mol dm⁻³ NaCl. Potentiometric data were refined using Hyperquad 2008, and the species distributions were simulated using HySS2009. The complexes of [MA_xH_y], with x = 1 to 3 and y = −4 to 2, were refined from three ligands at different temperatures and in the pH range from 2 to 11. The complex formation constant (log β) indicated that the complex of Gly-Pro-Hyp was the most stable followed by Pro-Hyp and Gly complexes. Thermodynamic analysis revealed that the formation of the complexes of [MA_xH_y], with x = 1 to 3 and y = 0, was spontaneous since the ΔG value was negative; this means that Gly, Pro-Hyp and Gly-Pro-Hyp have good iron chelating abilities and therefore, they can act as promising iron absorption promoters. The thermodynamic properties of these complexes were also studied, and the base for the usage of these complexes was provided.

Potentiometric titration to determine the complex formation constant of ferric ions with Gly, Pro-Hyp and Gly-Pro-Hyp.