Research progress of iron metabolism in retinal diseases.

Background: Retinal diseases can lead to severe visual impairment and even blindness, but current treatments are limited. For precise targeted therapy, the pathophysiological mechanisms of the diseases still need to be further explored. Iron serves an essential role in many biological activities and helps maintain the function and morphology of the retina. The vision problems caused by retinal diseases are affecting more and more people, the study of iron metabolism in retinal diseases possesses great potential for clinical application. Main text: Iron maintains a dynamic balance in the retina but in excess is toxic to the retina. Iron overload can lead to various pathological changes in the retina through oxidative stress, inflammation, cell death, angiogenesis and other pathways. It is therefore involved in the progression of retinal diseases such as age-related macular degeneration, glaucoma, diabetic retinopathy, retinitis pigmentosa, and hereditary iron overload. In recent years, iron chelators have been shown to be effective in the treatment of retinal diseases, but the exact mechanism is not yet fully understood. This question prompted further investigation into the specific mechanisms by which iron metabolism is involved in retinal disease. Conclusions: This review summarizes iron metabolism processes in the retina and mechanistic studies of iron metabolism in the progression of retinal disease. It also highlights the therapeutic potential of iron chelators in retinal diseases.

Torin 1 alleviates impairment of TFEB-mediated lysosomal biogenesis and autophagy in TGFBI (p.G623_H626del)-linked Thiel-Behnke corneal dystrophy.

Thiel-Behnke corneal dystrophy (TBCD) is an epithelial-stromal TGFBI dystrophy caused by mutations in the TGFBI (transforming growth factor beta induced) gene, though the underlying mechanisms and pathogenesis of TBCD are still obscure. The study identifies a novel mutation in the TGFBI gene (p.Gly623_His626del) in a TBCD pedigree. Characteristics of the typical vacuole formation, irregular corneal epithelial thickening and thinning, deposition of eosinophilic substances beneath the epithelium, and involvement of the anterior stroma were observed in this pedigree via transmission electron microscopy (TEM) and histological staining. Tgfbi-p.Gly623_Tyr626del mouse models of TBCD were subsequently generated via CRISPR/Cas9 technology, and the above characteristics were further verified via TEM and histological staining. Lysosomal dysfunction and downregulation of differential expression protein CTSD (cathepsin D) were observed using LysoTracker Green DND-26 and proteomic analysis, respectively. Hence, lysosomal dysfunction probably leads to autophagic flux obstruction in TBCD; this was supported by enhanced LC3-II and SQSTM1 levels and decreased CTSD. TFEB (transcription factor EB) was prominently decreased in TBCD corneal fibroblasts and administration of ATP-competitive MTOR inhibitor torin 1 reversed this decline, resulting in the degradation of accumulated mut-TGFBI (mutant TGFBI protein) via the ameliorative lysosomal function and autophagic flux owing to elevated TFEB activity as measured by western blot, confocal microscopy, and flow cytometry. Transfected HEK 293 cells overexpressing human full-length WT-TGFBI and mut-TGFBI were generated to further verify the results obtained in human corneal fibroblasts. Amelioration of lysosome dysfunction may therefore have therapeutic efficacy in the treatment of TBCD.Abbreviations AS-OCT: anterior segment optical coherence tomography; ATP: adenosine triphosphate; Cas9: CRISPR-associated protein 9; CLEAR: coordinated lysosomal expression and regulation; CRISPR: clustered regularly interspaced short palindromic repeats; CTSB: cathepsin B; CTSD: cathepsin D; CTSF: cathepsin F; CTSL: cathepsin L; DNA: deoxyribonucleic acid; ECM: extracellular matrix; Fas1: fasciclin 1; FC: flow cytometry; GAPDH: glyceraldeyde-3-phosphate dehydrogenase; GCD2: granular corneal dystrophy type 2; HE: hematoxylin and eosin; LAMP2: lysosomal-associated membrane protein; MT: mutation type; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; mut-TGFBI: mutant TGFBI protein; SD: standard deviation; TBCD: Thiel-Behnke corneal dystrophy; TEM: transmission electron microscopy; TFEB: transcription factor EB; TGFBI: transforming growth factor beta induced; WT: wild type.

Kojic acid enhances the proliferation of human corneal epithelial cells via p38 and p21 signaling pathways.

PURPOSE: Treatment of corneal injury depends on the self-proliferation ability of human corneal epithelial cells (HCEp). Our previous study revealed kojic acid had the anti-senescence function on human corneal endothelial cells. In this study, we researched the enhancive proliferation effect of kojic acid in HCEp. METHODS: Cell viability was evaluated by MTT assay. The expression of proliferation-related protein was detected by western blotting and immunofluorescence assay. RESULTS: Kojic acid could enhance HCEp proliferation, characterized by promoting cell proliferation rate, decreasing the expression levels of p21, galectin 8 and ki67, and increasing that of p-p38. The p38 signaling pathway inhibitor, SB203580, could reverse the enhancive proliferation function of kojic acid. Furthermore, knockdown of p21 had similar enhancive proliferation effect to kojic acid. CONCLUSION: Kojic acid might enhance HCEp proliferation through p38 and p21 signaling pathways, potentially via reduced expression levels of galectin 8 and ki67. Hence, kojic acid might be a potential drug to accelerate the healing of corneal epithelial injury.

The novel mutation P36R in LRP5L contributes to congenital membranous cataract via inhibition of laminin γ1 and c-MAF.

PURPOSE: The present study investigated a pathogenic mutation and its mechanism on membranous cataract in a congenital membranous cataract family. METHODS: An autosomal dominant four-generation Chinese congenital membranous cataract family was recruited and whole-exome sequencing was performed to screen for sequence variants. Candidate variants were validated using polymerase chain reaction and Sanger sequencing. Wild-type and mutant low-density lipoprotein receptor-related protein 5-like (LRP5L) plasmids were constructed and transfected into human lens epithelial cells (HLE B-3) and human anterior lens capsules. The cell lysates, nuclear and cytoplasmic proteins, and basement membrane components of HLE B-3 cells were harvested. LRP5L and laminin γ1 were knocked down in HLE B-3 cells using specific small-interfering RNA. The protein expression levels of LRP5L, laminin γ1, and c-MAF were detected using immunoblotting and immunofluorescence. RESULTS: We identified a novel suspected pathogenic mutation in LRP5L (c.107C > G, p.P36R) in the congenital membranous cataract family. This mutation was absent in 300 normal controls and 300 age-related cataract patients. Bioinformatics analysis with PolyPhen-2 and SIFT suggested that LRP5L-P36R was pathogenic. LRP5L upregulated laminin γ1 expression in the cytoplasmic proteins of HLE B-3 cells and human anterior lens capsules, and LRP5L-P36R inhibited the effects of LRP5L. LRP5L upregulated c-MAF expression in the nucleus and cytoplasm of HLE B-3 cells, and LRP5L-P36R inhibited c-MAF expression via inhibition of laminin γ1. CONCLUSION: Our study identified a novel gene, LRP5L, associated with congenital membranous cataract, and its mutant LRP5L-P36R contributed to membranous cataract development via inhibition of laminin γ1 and c-MAF.

Anti-human serum albumin autoantibody may be involved in the pathogenesis of autoimmune bullous skin diseases.

Although effective immunological diagnostic systems for autoimmune bullous skin diseases (AIBD) have been established, there are still unidentified cutaneous autoantigens. The purpose of this study is to investigative whether anti-human serum albumin (HSA) autoantibodies exist in AIBD sera and their potential pathogenesis. By immunoprecipitation-immunoblotting, immunofluorescence assay, anti-HSA autoantibodies could be detected in AIBD sera; by ELISAs, positive rates of AIBD sera for IgG and IgA anti-HSA autoantibodies were 29% and 34%, respectively. The IgG anti-HSA autoantibodies in ABID sera recognized a number of HSA antigen epitopes and therefore a polyclonal antibody against HSA were next employed to study its pathogenesis. In vitro cell and tissue culture models, anti-HSA antibody could influence DNA damage-related signaling proteins, via activation of phospho-p38 signaling pathway. This is the first report that an autoantibody may influence DNA damage-related signaling proteins. Statistical analyses also proved that anti-HSA autoantibodies were positively correlated with various known autoantibodies and clinical features of ABID patients. In summary, IgG and IgA autoantibodies to HSA may have diagnosis values for AIBD. DNA damage-related signaling proteins might be involved in the pathogenic role of anti-HSA autoantibodies in AIBD. Phospho-p38 signaling pathway is a potential target for treatment of AIBD positive for serum anti-HSA autoantibodies.

Retinal vascular abnormalities and their associations with cardiovascular and cerebrovascular diseases: a Study in rural southwestern Harbin, China.

BACKGROUND: Limited data is available on retinal vessel morphology in the north China. The study aimed to evaluate the prevalence of retinal vascular abnormalities (RVAs) and investigate their associations with the self-reported diagnosis of cardiovascular and cerebrovascsular diseases (CCVds) in a rural adult population of northeast China. METHODS: A population-based, cross-sectional study was conducted, using the cluster random sampling method. One eye of each participant was photographed with a non-mydriatic fundus camera. RVAs including focal and general arteriolar narrowing (FAN and GAN), arteriovenous nicking (AVN), arteriolar sheathing (AS), and retinopathy were evaluated. Data on self-reported diagnosis of cardiovascular and cerebrovascular diseases and status of smoking and alcohol drinking were obtained from questionnaires. RESULTS: Among the 6267 participants with an age ≥ 50 years, photographs were obtained of 99.2%, with quality sufficient to perform retinal evaluations in 82.5%. The prevalence of FAN, AVN, AS, retinopathy and GAN were 9.1, 8.9, 5.0, 6.6 and 6.2%, respectively. All the retinal lesions were associated with hypertension (all P < 0.01). After adjusting for age, gender, and left/right eyes, hypertension, hyperlipidaemia, diabetes mellitus, habits of past or current smoking and alcohol consumption, AVN was strongly associated with the self-reported diagnosis histories of coronary heart diseases(CHD) (OR, 1.44; 95% CI, 1.09, 1.89) and retinopathy was significantly associated with a self-reported diagnosis of stroke (OR, 2.05; 95% CI, 1.18, 3.57). CONCLUSIONS: The overall prevalence of retinal microvascular abnormalities in this population was relatively higher than that reported in other regions of the world. Retinopathy is associated with the self-reported diagnosis of stroke while AVN was associated with the self-reported diagnosis of CHD, but the remaining retinal lesions were not consistently associated with CCVds. Thus, an examination of retinal microvascular characteristics may offer clues to CCVds and could be a potentially novel biomarkers for CCVds risk.

Laminin α4 overexpression in the anterior lens capsule may contribute to the senescence of human lens epithelial cells in age-related cataract.

Senescence is a leading cause of age-related cataract (ARC). The current study indicated that the senescence-associated protein, p53, total laminin (LM), LMα4, and transforming growth factor-beta1 (TGF-ß1) in the cataractous anterior lens capsules (ALCs) increase with the grades of ARC. In cataractous ALCs, patient age, total LM, LMα4, TGF-ß1, were all positively correlated with p53. In lens epithelial cell (HLE B-3) senescence models, matrix metalloproteinase-9 (MMP-9) alleviated senescence by decreasing the expression of total LM and LMα4; TGF-ß1 induced senescence by increasing the expression of total LM and LMα4. Furthermore, MMP-9 silencing increased p-p38 and LMα4 expression; anti-LMα4 globular domain antibody alleviated senescence by decreasing the expression of p-p38 and LMα4; pharmacological inhibition of p38 MAPK signaling alleviated senescence by decreasing the expression of LMα4. Finally, in cataractous ALCs, positive correlations were found between LMα4 and total LM, as well as between LMα4 and TGF-ß1. Taken together, our results implied that the elevated LMα4, which was possibly caused by the decreased MMP-9, increased TGF-ß1 and activated p38 MAPK signaling during senescence, leading to the development of ARC. LMα4 and its regulatory factors show potential as targets for drug development for prevention and treatment of ARC.

Three kinds of corneal host cells contribute differently to corneal neovascularization.

BACKGROUND: Corneal neovascularization (angiogenesis and lymphangiogenesis) compromises corneal transparency and transplant survival, however, the molecular mechanisms of corneal host epithelial and stromal cells in neovascularization have not yet been fully elucidated. Furthermore, the contribution and mechanism of corneal host endothelial cells involved in neovascularization are largely unexplored. METHODS: Liquid chromatography-mass spectrometry, immunoblotting, and ELISA were used to screen and identify potential neovascularization-related factors in human full-thickness vascularized corneal tissues. Lipopolysaccharide was used to induce inflammation in three kinds of corneal host cells in vitro, including corneal epithelial, stromal, and endothelial cells. Fungus was used to establish an animal model of corneal neovascularization in vivo. Tube formation and spheroid sprouting assays were used to evaluate the contribution of three kinds of corneal host cells to the degree of neovascularization under various stimuli. Matrix metalloproteinase (MMP)-2, alpha-crystallin A chain (CRYAA), galectin-8, Bcl-2, neuropilin-2, MMP-9 plasmids, and recombinant human fibronectin were used to identify the key proteins of corneal host cells involved in corneal inflammatory neovascularization. FINDINGS: All three kinds of corneal host cells influenced corneal neovascularization to varying degrees. MMP-9 in human corneal epithelial cells, MMP-2, and CRYAA in human corneal stromal cells, and MMP-2 and galectin-8 in human corneal endothelial cells are potential key proteins that participate in corneal inflammatory neovascularization. INTERPRETATION: Our data indicated that both the effects of key proteins and corneal host cells involved should be considered for the treatment of corneal inflammatory neovascularization.

Kojic acid inhibits senescence of human corneal endothelial cells via NF-κB and p21 signaling pathways.

Fuchs endothelial dystrophy (FED) and late cornea allograft failure of cornea transplantation are associated with human corneal endothelial cells (HCEC) senescence. Kojic acid has various functions, however, its anti-senescence effect has never been identified. In this study, we investigated the anti-senescence effect of kojic acid on HCEC. Cell viability, migration ability and senescence were evaluated by MTT assay, migration assay, and senescence-associated beta-galactosidase (SA-ß-Gal) staining, respectively. Senescence-related protein expression was analyzed by western blotting and immunofluorescence assay. Angiogenesis of human umbilical vein endothelial cells (HUVEC) was examined by tube formation assay and spheroid sprouting assay. The results showed that kojic acid could inhibit HCEC senescence, characterized by enhancing migration, decreasing the levels of SA-ß-Gal staining, galectin 8, laminin α1, laminin α2, laminin γ1 and p21, and increasing that of p-NF-κB of senescent HCEC. The p-NF-κB inhibitor could reverse the anti-senescent effect of kojic acid, and p21 siRNA showed similar anti-senescence effect with kojic acid. In addition, kojic acid could alleviate HUVEC tube formation induced by senescent HCEC, which could be reversed by p-NF-κB inhibitor. The p21 siRNA could alleviate HUVEC spheroid sprouting induced by senescent HCEC. These results indicated that kojic acid might inhibit HCEC senescence and following resulted angiogenesis via NF-κB and p21 signaling pathways, possibly through downregulation of galectin 8 and laminins. Therefore, kojic acid is a promising drug for HCEC senescence-related diseases such as FED and late cornea allograft failure.

Caspase-10, matrix metalloproteinase-9 and total laminin are correlated with the tumor malignancy of clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is a common malignant kidney tumor, the pathogenesis of which remains unclear. The aim of the present study was to investigate whether caspase-10, matrix metalloproteinase-9 (MMP-9) and total laminin (LM) were involved into the pathogenesis of ccRCC. The levels of caspase-10, MMP-9 and total LM were analyzed by ELISA in tumor tissues and adjacent non-malignant tissues of 27 patients with ccRCC. The results revealed that caspase-10 levels in the tumor tissues were significantly higher than those in the adjacent non-malignant tissues (P<0.05). The MMP-9 levels in the tumor tissues were significantly lower than those in adjacent non-malignant tissues (P<0.01). The total LM levels in tumor tissues revealed no statistical difference with those in the adjacent non-malignant tissues (P=0.757). Additionally, caspase-10 levels were positively correlated with MMP-9 levels (P<0.001), but negatively correlated with total LM levels (P<0.05) in tumor tissues. Correlation analyses with clinical data of patients with ccRCC, revealed that caspase-10 levels (P<0.05) and MMP-9 levels (P<0.001) in tumor tissues were positively correlated with tumor grades of ccRCC, whereas total LM levels were positively correlated with tumor size (P<0.05). The results of the present study suggested that interactions between caspase-10, MMP-9 and LM are likely involved in the pathogenesis of ccRCC. A deeper understanding of the correlation between caspase-10, MMP-9 and LM would aid the clarification of pathogenesis of ccRCC.

Laminins in an in vitro anterior lens capsule model established using HLE B-3 cells.

Cataracts are the most common eye disease to cause blindness in patients. The abnormal deposition of laminins (LMs) in the lens capsule and the disruption of capsular epithelium contribute to cataract development, although the mechanism by which this occurs is currently unclear. The present study aimed to reproduce HLE B­3 basement membranes (BMs) using HLE B­3 cells and to analyze the similarities of LM expression between HLE B­3 BMs and human anterior lens capsule (ALC). Immunohistochemistry (IHC), ELISA, western blot analysis and immunoprecipitation (IP)­western blot analysis were used to detect total LMs, LM trimers and 11 LM subunits in HLE B­3 cells, HLE B­3 BMs and human ALCs. In IHC staining, HLE B­3 cells and human ALCs were positive for LMs. In LM ELISA, all samples analyzed were positive for LMs. Western blot analysis detected all LM subunits except for LMγ3 in HLE B­3 cell lysate, 4 subunits (LMα4, LMα2, LMα1 and LMγ1) in HLE B­3 cell culture supernatant, 5 subunits (LMα4, LMα2, LMα1, LMß3 and LMγ1) in HLE B­3 BMs, and 3 subunits (LMα4, LMγ2 and LMγ1) in human ALCs. The results of IP­western blot analysis revealed that the LM411 trimer was detected in HLE B­3 cell culture supernatant. These results indicated that HLE B­3 BMs were similar to human ALCs in terms of LM expression. Therefore, HLE B­3 BMs could be used as an in vitro ALC model to determine the role of LMs in ALC in the pathogenesis of cataracts and to select potential anti­cataract drugs.

CHST6 mutation screening and endoplasmatic reticulum stress in macular corneal dystrophy.

Macular corneal dystrophy (MCD) is an autosomal recessive disorder mainly caused by gene mutations of carbohydrate sulfotransferase (CHST6) leading to bilateral visual impairment. Because the mechanism underlying this degeneration remains poorly understood, we investigated molecular alterations and pathways that may be involved in MCD in this issue. Different mutation sites were screened by direct sequencing of the coding region of CHST6. In addition, we described morphological changes in MCD keratocytes by light microscopy and electron microscopy and determined the relationship between the development of this disease and the occurrence of apoptosis through flow cytometry, cell counting kit-8, colony formation assay and other experiments. Western blotting and quantitative real-time polymerase chain reaction were used to determine if endoplasmic reticulum (ER) stress was activated. We found 10 kinds of mutations among these families with 3 novel mutations included. The percentage of apoptotic keratocytes increased in MCD patients; furthermore, the expression of apoptosis related protein B-cell lymphoma-2 (Bcl-2) was down-regulated while Bcl-2 associated X protein was upregulated. Finally, ER stress was activated with the upregulation of glucose-regulated protein 78 and CCAAT-enhancer-binding protein homologous protein. Our clinical and in vitro results suggest that the CHST6 mutation associated with MCD is associated with apoptosis, and ER stress is probably involved in this apoptosis pathway.

QishenYiqi Dripping Pill Improves Heart Failure by Up-Regulation of ß2-Adrenergic Receptor Expression.

BACKGROUND: QishenYiqi Dripping Pill (QYDP) is a Chinese herbal medicine that originally was used for the treatment of coronary artery disease. Recently, QYDP was used as a complementary treatment for heart failure (HF) in China. METHODS: An HF rat model was used to clarify the possible therapeutic effects of QYDP on HF. The HF rats were allocated to two groups, HF and HF+QYDP, while normal rats served as a negative control. Cardiac functions were evaluated echocardiographically and hemodynamically. Cardiac apoptosis and the expression of ß-adrenergic receptors were also investigated. RESULTS: Compared to the HF group, rats in the HF+QYDP group had a significantly higher fraction shortening (p<0.05), ejection fraction (p<0.05), left ventricular systolic pressure (p<0.05), maximum positive derivatives of left ventricular pressure (p<0.05), maximum negative derivatives of left ventricular pressure (p<0.05), and ß2-adrenergic receptor expression (p<0.05), and lower left ventricular end-diastolic pressure (p<0.05) and apoptotic index (p<0.05). CONCLUSIONS: The study results indicated that QYDP could efficiently improve HF, possibly by an inhibition of cardiac apoptosis via the ß2-adrenergic receptor signaling pathway. Hence, QYDP might be a promising candidate drug for HF therapy.

Blockade of MMP-2 and MMP-9 inhibits corneal lymphangiogenesis.

PURPOSE: To investigate the roles of a selective MMP-2 and -9 inhibitor (SB-3CT) in corneal inflammatory lymphangiogenesis. METHODS: The expression of MMP-2 and -9 in the cornea after suture inplacement, treated with SB-3CT or negative control, was detected by real-time polymerase chain reaction (PCR). Inflammatory corneal neovascularization (NV) was induced by corneal suture placement. Mice were treated with SB-3CT eye drops (twice daily for 1 week, 5 µL per drop; 50, 100, or 200 µM). The outgrowth of blood and lymphatic vessels, and macrophage recruitment were analyzed by immunofluorescence assay. The expressions of vascular endothelial growth factor-C (VEGF-C) and its receptor VEGFR-3 were tested by real-time PCR. RESULTS: MMP-2 and -9 expression were suppressed significantly by treatment with SB-3CT. The data demonstrated, for the first time, that SB-3CT strongly reduced corneal lymphangiogenesis and macrophage infiltration during inflammation. Furthermore, expressions of VEGF-C and its receptor VEGFR-3 were significantly inhibited by SB-3CT during corneal lymphangiogenesis. CONCLUSIONS: These novel findings indicated that blockade of MMP-2 and -9 could inhibit lymphangiogenesis. Further investigation of this factor may provide novel therapies for transplant rejection and other lymphatic disorders.

Neuropilin-2 contributes to LPS-induced corneal inflammatory lymphangiogenesis.

Neuropilin-2 (NP2), a high-affinity kinase-deficient co-receptor for vascular endothelial growth factor (VEGF)-C, is involved in embryonic vessel development, tumor growth, tumor lymphangiogenesis and metastasis. However, the pathological role of NP2 in other disorders, particularly under inflammatory lymphangiogenic conditions, remains largely unknown. In this study, we investigated the role of NP2 in inflammation-induced lymphangiogenesis in vivo using a lipopolysaccharide (LPS)-induced corneal neovascularization mouse model and in vitro using a macrophage-mouse lymphatic endothelial cell (mLEC) co-culture system. In the mouse model of LPS-induced inflammatory corneal neovascularization, NP2 and VEGFR-3 expression were rapidly up-regulated after LPS stimulation, and microRNA-mediated knockdown of NP2 significantly inhibited the up-regulation of VEGFR-3. Moreover, NP2 knockdown specifically inhibited the increase in the number of corneal lymphatic vessels but did not influence the increase in the number of blood vessels or macrophage recruitment induced by LPS. In a macrophage-LEC co-culture system, LPS up-regulated VEGFR-3 expression and induced mLEC migration and proliferation, and NP2 knockdown inhibited the up-regulation of VEGFR-3 expression and mLEC migration but not proliferation. Taken together, these results suggested that NP2 might be involved in the regulation of lymphangiogenesis via the regulation of VEGFR-3 expression during corneal inflammation. Therefore, NP2-targeted therapy might be a promising strategy for selective inhibition of inflammatory lymphangiogenesis in corneal inflammatory diseases, transplant immunology and oncology.

Use of a silk fibroin-chitosan scaffold to construct a tissue-engineered corneal stroma.

PURPOSE: To construct a scaffold using silk fibroin (SF) and chitosan (CS) that could replace the corneal stroma with the biological characteristics of the scaffold materials still intact. METHODS: To develop an organotypic corneal stroma, SF and CS were chosen to synthesise the tissue-engineered bioscaffold. We cultured primary rabbit corneal epithelial cells and corneal stromal cells in vitro. Keratocytes were used to assess cytotoxicity on SF-CS (SFCS) blends, which was determined by a Cell Counting Kit-8 assay. The corneal lamellar scaffolds were developed with sequential culture techniques to form cell-scaffold constructs. Implantation was tested in 15 New Zealand White rabbits. The corneal substitutes were analysed by light and electron microscopy. RESULTS: The reconstructed lamellar cornea was comparable to native tissue, with high levels of K3/12 expression in the corneal epithelial cells and vimentin in the stromal cells; moreover, the morphology and the position of the cells could be distinguished by histological methods. There was no sign of any immune reaction in or around the transplanted discs 12 weeks after implantation. CONCLUSION: A SFCS scaffold might be a suitable blend for corneal tissue engineering.

Chitosan-functionalized silk fibroin 3D scaffold for keratocyte culture.

The goal of this study was to evaluate the potential suitability of an artificial membrane composed of silk fibroin (SF) functionalized by different ratios of chitosan (CS) as a substrate for the stroma of the cornea. Keratocytes were cultured on translucent membranes made of SF and CS with different ratios. The biophysical properties of the silk fibroin and chitosan (SF/CS) membrane were examined. The SF/CS showed tensile strengths that increased as the CS concentration increased, but the physical and mechanical properties of chitosan-functionalized silk fibroin scaffolds weakened significantly compared with those of native corneas. The resulting cell scaffolds were evaluated using western blot in addition to light and electron microscopy. The cell attachment and proliferation on the scaffold were similar to those on a plastic plate. Keratocytes cultured in serum on SF/CS exhibited stellate morphology along with a marked increase in the expression of keratocan compared with identical cultures on tissue culture plastics. The biocompatibility was tested by transplanting the acellular membrane into rabbit corneal stromal pockets. There was no inflammatory complication detected at any time point on the macroscopic level. Taken together, these results indicate that SF/CS holds promise as a substrate for corneal reconstruction.

Propofol increases the Ca2+ sensitivity of BKCa in the cerebral arterial smooth muscle cells of mice.

AIM: Propofol has the side effect of hypotension especially in the elderly and patients with hypertension. Previous studies suggest propofol-caused hypotension results from activation of large conductance Ca(2+)-sensitive K channels (BKCa). In this study, the effects of propofol on the Ca(2+) sensitivity of BKCa were investigated in mice cerebral arterial smooth muscle cells. METHODS: Single smooth muscle cells were prepared from the cerebral arteries of mice. Perforated whole-cell recoding was conducted to investigate the whole-cell BKCa current and spontaneous transient outward K(+) current (STOC). Inside-out patch configuration was used to record the single channel current and to study the Ca(2+)- and voltage-dependence of BKCa. RESULTS: Propofol (56 and 112 µmol/L) increased the macroscopic BKCa and STOC currents in a concentration-dependent manner. It markedly increased the total open probability (NPo) of single BKCa channel with an EC(50) value of 76 µmol/L. Furthermore, propofol significantly decreased the equilibrium dissociation constant (K(d)) of Ca(2+) for BKCa channel. The K(d) value of Ca(2+) was 0.881 µmol/L in control, and decreased to 0.694, 0.599 and 0.177 µmol/L, respectively, in the presence of propofol 28, 56 and 112 µmol/L. An analysis of the channel kinetics revealed that propofol (112 µmol/L) significantly increased the open dwell time and decreased the closed dwell time, which stabilized BKCa channel in the open state. CONCLUSION: Propofol increases the Ca(2+) sensitivity of BKCa channels, thus lowering the Ca(2+) threshold of the channel activation in arterial smooth muscle cells, which causes greater vasodilating effects.

[Gene mapping and mutation detection in a family with congenital anterior polar cataract].

OBJECTIVE: To map the gene mutation responsible for autosomal dominant inherited congenital anterior polar cataract in a Chinese family. METHODS: Peripheral blood samples were collected from the members in this congenital cataract family. DNA was extracted from the blood samples. A gene scan was performed using approximately 400 microsatellite markers (ABI). Linkage analysis was processed to define the region of mutated gene. High density primers labeled with fluorescent stain for the positive region were adopted for fine targeting and haplotype analysis was performed. Mutation detection was carried out by sequencing candidate genes. RESULTS: The maximum two-point LOD score was obtained at D21S1252, Z(max) = 3.23 (θ(max) = 0.00). After fine targeting and haplotype analysis, the mutated gene was located within a 18.47 cM region between D21S263 and D21S266 on chromosome 21q22.11-q22.3. Direct sequencing of the candidate gene revealed a G©öA transition in exon 3 of CRYAA. CONCLUSION: The present study has identified a missense mutation in CRYAA associated with congenital anterior polar cataract in a Chinese family.

Congenital anterior polar cataract associated with a missense mutation in the human alpha crystallin gene CRYAA.

PURPOSE: To identify the potential pathogenic mutation over four generations of a Chinese family with congenital anterior polar cataracts (APC). METHODS: We investigated four generations of a Chinese family who are afflicted with anterior polar cataracts. The family resides in a relatively isolated region of Northern China. Peripheral blood samples were collected from all of the family members, and genomic DNA was then extracted from the blood samples. A gene scan was performed using about 400 primers labeled with fluorescent stain. Linkage software defined the region of the diseased gene with a Linkage analysis, and Cyrillic software processed the resulting haplotypes. Mutation detection was performed in the candidate gene by sequencing amplified products. RESULTS: A maximum logarithm of odds score (LOD) score was obtained at marker D21S1252(LOD score [Z]=3.23, recombination fraction [θ]=0.0. Haplotype analysis traced the disease gene to an 18.47 cM region bounded by D21S263 and D21S266 on chromosome21q22.11-q22.3. Direct sequencing of the candidate alpha A crystallin (CRYAA) gene revealed a c.347G>A transition in exon 3 of CRYAA that co-segregated with the cataract in the family members and was not observed in 100 control patients. This single-nucleotide change resulted in the substitution of a highly conserved Arginine by Histidine (R116H). CONCLUSIONS: The present study identified a missense mutation (R116H) in the CRYAA gene that causes autosomal dominant congenital anterior polar cataracts in a Chinese family. Our finding confirms the high rate of apparently independent mutations at this dinucleotide.