Transcriptional regulation of the Japanese flounder Cu,Zn-SOD (Jfsod1) gene in RAW264.7 cells during oxidative stress caused by causative bacteria of edwardsiellosis.

Edwardsiellosis is one of the most important bacterial diseases in fish, sometimes causing extensive economic losses in the aquaculture industry. Our previous studies demonstrated that the Cu,Zn-SOD (sod1) activity has significantly increased in Japanese flounder, Paralichthys olivaceus, hepatopancreas infected by causative bacteria of edwardsiellosis Edwardsiella tarda NUF251. In this study, NUF251 stimulated intracellular superoxide radical production in mouse macrophage RAW264.7 cells, which was reduced by N-acetylcysteine. This result suggests that NUF251 infection causes oxidative stress. To evaluate the regulatory mechanism of Jfsod1 at transcriptional levels under oxidative stress induced by NUF251 infection, we cloned and determined the nucleotide sequence (1124 bp) of the 5'-flanking region of the Jfsod1 gene. The sequence analysis demonstrated that the binding sites for the transcription factors C/EBPα and NF-IL6 involved in the transcriptional regulation of the mammalian sod1 gene existed. We constructed a luciferase reporter system with the 5'-flanking region (-1124/-1) of the Jfsod1 gene, and a highly increased transcriptional activity of the region was observed in NUF251-infected RAW264.7 cells. Further studies using several mutants indicated that deletion of the recognition region of NF-IL6 (-272/-132) resulted in a significant decrease in the transcriptional activity of the Jfsod1 gene in NUF251-infected RAW264.7 cells. In particular, the binding site (-202/-194) for NF-IL6 might play a major role in upregulating the transcriptional activity of the 5'-flanking region of the Jfsod1 gene in response to oxidative stress induced by NUF251 infection. These results could be provided a new insight to understand the pathogenic mechanism of causative bacteria of edwardsiellosis.

Locking water molecules via ternary O-H⋯O intramolecular hydrogen bonds in perhydroxylated closo-dodecaborate.

A multitude of applications related to perhydroxylated closo-dodecaborate B12(OH)122- in the condensed phase are inseparable from the fundamental mechanisms underlying the high water orientation selectivity based on the base B12(OH)122-. Herein, we directly compare the structural evolution of water clusters, ranging from monomer to hexamer, oriented by functional groups in the bases B12H122-, B12H11OH2- and B12(OH)122- using multiple theoretical methods. A significant revelation is made regarding B12(OH)122-: each additional water molecule is locked into the intramolecular hydrogen bond B-O-H ternary ring in an embedded form. This new pattern of water cluster growth suggests that B-(H-O)⋯H-O interactions prevail over the competition from water-hydrogen bonds (O⋯H-O), distinguishing it from the behavior observed in B12H122- and B12H11OH2- bases, in which competition arises from a mixed competing model involving dihydrogen bonds (B-H⋯H-O), conventional hydrogen bonds (B-(H-O)⋯H-O) and water hydrogen bonds (O⋯H-O). Through aqueous solvation and ab initio molecular dynamics analysis, we further demonstrate the largest water clusters in the first hydrated shell with exceptional thermodynamic stability around B12(OH)122-. These findings provide a solid scientific foundation for the design of boron cluster chemistry incorporating hydroxyl-group-modified borate salts with potential implications for various applications.

Beyond Duality: Rationalizing Repulsive Coulomb Barriers in Host-Guest Cyclodextrin-Dodecaborate Complexes.

The repulsive Coulomb barrier (RCB), an intrinsic potential energy barrier along electron detachment or charge-separation coordinates in multiply charged anions (MCAs), provides dynamic stability to MCAs whose electronic and thermodynamic stabilities are largely dictated by strong internal Coulomb repulsions. Spectroscopic and theoretical characterizations of the RCB have been focused on isolated MCAs. In this work, we extend the RCB investigation beyond the previous scope by including noncovalent host-guest cyclodextrin-closo-dodecaborate dianionic complexes χCD·B12X122- (χ = α, ß, γ; X = H, F-I). Photodechment photoelectron spectroscopy reveals the existence of two distinctly different RCBs, derived from detaching electrons from the guest dianions (RCB1) or ionizing the host neutrals (RCB2), respectively, with the latter being substantially smaller than the former. Theoretical calculations support the duality of RCBs in these complexes and further exhibit highly anisotropic nature of the RCBs.

Identification of a Tissue Inhibitor of Metalloproteinase-2: An Endogenous Inhibitor of Modori-Inducing Insoluble Metalloproteinase from Yellowtail Seriola quinqueradiata Muscle.

The existence of an endogenous protease inhibitor (EPI) was expected from the comparison of the gel properties between washed and nonwashed yellowtail surimi gels. A possible candidate, tissue inhibitor of metalloproteinase-2 (TIMP-2), was partially purified from the soluble fraction of yellowtail muscle, and an 18 kDa protein band was detected by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions and western blot analysis. Its N-terminal amino acid sequence was determined as XSXSPAHPQQAF, with high homology to TIMP-2 from other fish species, suggesting that it was identified as yellowtail TIMP-2. Subsequently, full-length cDNA of two isoforms (TIMP-2a and TIMP-2b) was successfully cloned from yellowtail muscle. The N-terminal sequence of purified TIMP-2 completely corresponded to TIMP-2b. When the surimi gel quality decreased after spawning, the mRNA expression of TIMP-2b also decreased. Human TIMP-2 could inhibit autolysis of myofibrillar proteins from yellowtail muscle. Thus, TIMP-2b was considered the major EPI of the modori-inducing insoluble metalloproteinase in yellowtail muscle.

Highly Structured Water Networks in Microhydrated Dodecaborate Clusters.

We report a combined photoelectron spectroscopy and theoretical investigation of a series of size-selected hydrated closo-dodecaborate clusters B12X122-·nH2O (X = H, F, or I; n = 1-6). Distinct structural arrangements of water clusters from monomer to hexamer can be achieved by using different B12X122- bases, illustrating the evident solute specificity. Because B-H···H-O dihydrogen bonds are stronger than O···H-O hydrogen bonds in water, the added water molecules are arranged in a unified binding mode by forming highly structured water networks manipulated by B12H122-. As a comparison, the hydrated B12F122- clusters display similar water evolution for n values of 1 and 2 but different binding modes for larger clusters, while water networks in B12I122- share similarities with the free water clusters. This finding provides a consistent picture of the structural diversity of hydrogen bonding networks in microhydrated dodecaborates and a molecular-level understanding of microsolvation dynamics in aqueous borate chemistry.

Guideline for the treatment of no light perception eyes induced by mechanical ocular trauma.

Severe mechanical ocular trauma with no light perception (NLP) predicts a poor prognosis of visual acuity and enucleation of the eyeball. Since the innovative treatment concept of exploratory vitreoretinal surgery has developed and treatment technology has advanced, the outcomes of severe ocular trauma treatment in NLP patients have greatly improved. However, there remains a lack of unified standards for the determination, surgical indication, and timing of vitrectomy in NLP eye treatment. To address these problems, we aimed to create evidence-based medical guidelines for the diagnosis, treatment, and prognosis of mechanical ocular trauma with NLP. Sixteen relevant recommendations for mechanical ocular trauma with NLP were obtained, and a consensus was reached. Each recommendation was explained in detail to guide the treatment of mechanical ocular trauma associated with NLP.

Unraveling hydridic-to-protonic dihydrogen bond predominance in monohydrated dodecaborate clusters.

Hydridic-to-protonic dihydrogen bonds (DHBs) are involved in comprehensive structural and energetic evolution, and significantly affect reactivity and selectivity in solution and solid states. Grand challenges exist in understanding DHBs' bonding nature and strength, and how to harness DHBs. Herein we launched a combined photoelectron spectroscopy and multiscale theoretical investigation using monohydrated closo-dodecaborate clusters B12X12 2-·H2O (X = H, F, I) to address such challenges. For the first time, a consistent and unambiguous picture is unraveled demonstrating that B-H⋯H-O DHBs are superior to the conventional B-X⋯H-O HBs, being 1.15 and 4.61 kcal mol-1 stronger than those with X = F and I, respectively. Energy decomposition analyses reveal that induction and dispersion terms make pronounced contributions resulting in a stronger B-H⋯H-O DHB. These findings call out more attention to the prominent roles of DHBs in water environments and pave the way for efficient and eco-friendly catalytic dihydrogen production based on optimized hydridic-to-protonic interactions.

Comparison of Intravitreal Anti-VEGF Agents With Laser Photocoagulation for Retinopathy of Prematurity of 1,627 Eyes in China.

Purpose: To compare the efficacies and treatment outcomes of intravitreal anti-VEGF agents and laser therapy in retinopathy of prematurity (ROP). Methods: A retrospective, non-randomized, comparative study of patients diagnosed with type 1 ROP or aggressive posterior ROP (A-ROP) treated with intravitreal anti-VEGF agents or laser therapy as primary treatment at the People's Hospital of Peking University. Results: A total of 1,627 eyes of 862 patients were included. In Group 1, 399 eyes of 204 patients were diagnosed with A-ROP or zone I type 1 ROP. The initial regression of the anti-VEGF subgroup was better than that of the laser subgroup, and the reactivation rate and rate of progression to retinal detachment were lower than those of the laser subgroup. In Group 2, 1,228 eyes of 658 patients were diagnosed with zone II type 1 ROP. The reactivation rate of the laser subgroup was lower than that of the anti-VEGF subgroup. No significant differences were found in the initial regression and the probability of developing retinal detachment. Among the anti-VEGF agents, the reactivation rate in eyes treated with conbercept was much lower than that in eyes treated with ranibizumab. The spherical power and spherical equivalents of eyes treated with laser were significantly higher than those of eyes treated with anti-VEGF agents 1 year after initial treatment. Conclusions: In contrast to laser therapy, anti-VEGF agents as primary treatments have potential advantages for eyes with zone I type 1 ROP and A-ROP. For eyes with zone II type 1 ROP, laser photocoagulation and anti-VEGF agents therapy showed similar efficacy; however, the rate of reactivation with laser therapy was significantly lower than that with anti-VEGF agents. Among the anti-VEGF agents, the reactivation rate was much lower in eyes treated with conbercept than in eyes treated with ranibizumab. Compared to anti-VEGF agents, laser treated eyes had greater trend to myopia.

Excited State Dynamics of Methylated Guanosine Derivatives Revealed by Femtosecond Time-resolved Spectroscopy.

Methylated DNA/RNA nucleobases are important epigenetic marks in living species and play an important role for targeted therapies. Moreover, methylation could bring significant changes to the photo-stability of nucleic acid, leading these sites become mutational hotspots for disease such as skin cancer. While a number of studies have demonstrated the relationship between excited state dynamics and the biological function of methylated cytosine in DNA, investigations aimed at unraveling the excited state dynamics of methylated guanosine in RNA have been largely overlooked. In this work, influence of methylation on the excited state dynamics of guanosine is studied by using femtosecond time-resolved spectroscopy. Our results suggest that the effect of methyl substitution on the photophysical properties of guanosine is position sensitive. N1-methylguanosine shows very similar excited state dynamics as that in guanosine, while almost one order of magnitude longer lifetime of the La state is observed in N2, N2-dimethylguanosine. Notably, N7-methylation can lead to a new minimum on the La state and the excited state lifetime is two orders of magnitude longer than that of guanosine. These findings not only help understanding excited state dynamics of methylated guanosines, but also lay the foundation for further studying DNA/RNA strands incorporated with these bases.

Near-Unity Triplet Generation Promoted via Spiro-Conjugation.

An intersystem crossing (ISC) rate constant of 1.0×1011  s-1 was previously registered with a spiro-bis-benzophenone scaffold. Triplet generation efficiency could be further enhanced by stabilizing the spiro-charge-transfer (CT) state and rationally designing spiro-compounds (SCTs) that consist of electron-rich diphenyl ether as the spiro-CT donor and electron-deficient dinaphthyl ketone as the spiro-CT acceptor. Through fine-tuning of the energy level between the CT and high energy triplet states, near-unity triplet generation quantum yield was achieved and the underlying ISC mechanism is revealed by using ultrafast spectroscopy and quantum chemical calculations. Potential triplet sensitizing application was demonstrated in SCTs. Our findings suggest that a spiro-bichromophoric molecular system with an enhanced spiro-charge transfer warrants efficient triplet generation and is a powerful strategy of heavy-atom-free triplet sensitizers with predictable ISC properties.

Achieving Adjustable Multifunction Based on Host-Guest Interaction-Manipulated Reversible Molecular Conformational Switching.

Small molecules that are capable of toggling between multiple and definite conformational states under external stimuli have great potential for use in molecular switches or sensors. However, currently developed regulation approaches for these switchable molecules mostly involve covalent bond-breaking/reforming processes, thereby inevitably producing byproducts or causing fatigue accumulation. Herein, we report a simple but successful model whose molecular conformation can be precisely manipulated between stretched and folded forms by employing host-guest interactions with rigid macrocycles, thus avoiding possible side reactions and fatigue accumulation and possessing excellent reversibility. Moreover, the conformation states of this molecule can be visualized and identified by luminous readout, endowing it with real-time self-reporting features. Furthermore, this controllable and reversible conformational conversion is accompanied by various valuable functions, including controllable multicolor emission; ratiometric fluorescent thermosensing with high temperature resolution, excellent reversibility, lock/unlock switching, and especially linear detection range tunability; and in addition real-time intracellular temperature sensing and imaging, disclosing the intriguing microscopic "conformation-function" relationship based on a single molecule.

Gaseous cyclodextrin-closo-dodecaborate complexes χCD·B12X122- (χ = α, ß, and γ; X = F, Cl, Br, and I): electronic structures and intramolecular interactions.

A fundamental understanding of cyclodextrin-closo-dodecaborate inclusion complexes is of great interest in supramolecular chemistry. Herein, we report a systematic investigation on the electronic structures and intramolecular interactions of perhalogenated closo-dodecaborate dianions B12X122- (X = F, Cl, Br and I) binding to α-, ß-, and γ-cyclodextrins (CDs) in the gas phase using combined negative ion photoelectron spectroscopy (NIPES) and density functional theory (DFT) calculations. The vertical detachment energy (VDE) of each complex and electronic stabilization of each dianion due to the CD binding (ΔVDE, relative to the corresponding isolated B12X122-) are determined from the experiments along α-, ß- and γ-CD in the form of VDE (ΔVDE): 4.00 (2.10), 4.33 (2.43), and 4.30 (2.40) eV in X = F; 4.09 (1.14), 4.64 (1.69), and 4.69 (1.74) eV in X = Cl; 4.11 (0.91), 4.58 (1.38), and 4.70 (1.50) eV in X = Br; and 3.54 (0.74), 3.88 (1.08), and 4.05 (1.25) eV in X = I, respectively. All complexes have significantly higher VDEs than the corresponding isolated dodecaborate dianions with ΔVDE spanning from 0.74 eV at (α, I) to 2.43 eV at (ß, F), sensitive to both host CD size and guest substituent X. DFT-optimized complex structures indicate that all B12X122- prefer binding to the wide openings of CDs with the insertion depth and binding motif strongly dependent on the CD size and halogen X. Dodecaborate anions with heavy halogens, i.e., X = Cl, Br, and I, are found outside of α-CD, while B12F122- is completely wrapped by γ-CD. Partial embedment of B12X122- into CDs is observed for the other complexes via multipronged B-XH-O/C interlocking patterns. The simulated spectra based on the density of states agree well with those of the experiments and the calculated VDEs well reproduce the experimental trends. Molecular orbital analyses suggest that the spectral features at low binding energies originated from electrons detached from the dodecaborate dianion, while those at higher binding energies are derived from electron detachment from CDs. Energy decomposition analyses reveal that the electrostatic interaction plays a dominating role in contributing to the host-guest interactions for the X = F series partially due to the formation of a O/C-HX-B hydrogen bonding network, and the dispersion forces gradually become important with the increase of halogen size.

New Insights about the Photostability of DNA/RNA Bases: Triplet nπ* State Leads to Effective Intersystem Crossing in Pyrimidinones.

The high photostability of DNA/RNA nucleobases is attributed to the effective internal conversions of their bright 1ππ* states to the ground state through conical intersections. Intersystem crossing (ISC) from singlet to triplet excited states is a minor decay pathway in nucleobases and it is observed with ∼1-2% quantum yields (QYs) in pyrimidine bases. Presumably, ISC in pyrimidines takes place from the dark singlet 1nπ* state to the lowest triplet 3ππ* state. However, recent studies showed that ISC from the initial populated bright 1ππ* state to higher energy triplet 3nπ* states indeed occurs in the subpicosecond timescale. Such a mechanism is still poorly understood since direct observation of this pathway is challenging. Herein, excited state dynamics of three pyrimidinones, which share the same skeleton with pyrimidine bases, is investigated in different solvents. Compared to canonical pyrimidine bases, removing the oxygen atom at the C4 position revokes the low-lying dark 1nπ* state in pyrimidinones, resulting in direct ISC from the S1 (1ππ*) state to triplet T3 (3nπ*) state with much higher QYs. Meanwhile, hydrogen bonding between the carbonyl group in pyrimidinones and protic solvents can accelerate vibrational cooling of the hot S1 (1ππ*) state, leading to higher fluorescence QYs and smaller ISC rate constants. These results not only evidence the hypothesis of the direct 1ππ* → 3nπ* ISC mechanism, but also contribute to a better understanding of triplet formation in pyrimidines.

Mechanism and prognostic indicators for explosion-related eye trauma: eye injury vitrectomy study.

PURPOSE: To explore the clinical features, surgical interventions and prognosis of injured eyes following explosion and to develop the risk factors for poor prognosis. METHODS: A nested case-control study. To the date of 31 December 2018, 99 explosion-related eye globes were selected from the Eye Injury Vitrectomy Study database, which is a multicenter prospective cohort study and began in 1990s. All cases selected underwent vitreoretinal surgery or enucleation and were followed up for at least 6 months. Clinically meaningful preoperative variables and outcomes were used to develop logistic regression models. RESULTS: The unfavourable outcomes were defined as silicone oil-filled eyes, phthisis bulbi, enucleation and anatomically restored eyes whose final BCVA is worse than initial vision after 6 months of follow-up. The proportion of unfavourable outcomes was 92.0%, 60.9% and 66.7% in large festive fireworks, detonator and beer bottle groups respective. The anatomic and visual outcome of injured eyes with combined injury of blast wave and projectile were worse than that of ruptured eyes (Fisher's exact = 0.041). The extrusion of iris/lens (OR = 3.20, p = 0.015), PVR-C (OR = 6.08, p = 0.036) and choroid damage (OR = 5.84, p = 0.025) is independent risk factors of unfavourable prognosis for explosion-related eye trauma. CONCLUSION: The extrusion of iris/lens, PVR-C and choroid damage is the independent risk factors for unfavourable outcomes in explosion-related eye trauma. There is a unique injury mechanism in explosion-related eye trauma. SUMMARY STATEMENT: Through the nested case-control study, the extrusion of iris/lens, PVR-C, and choroid damage are the independent risk factors for unfavorable outcomes in explosion-related eye trauma. The mechanism of open globe mixture and close globe mixture in explosion-related eye trauma need more cases and participating units to explore together in the future.

Orthogonal Self-Assembly of a Two-Step Fluorescence-Resonance Energy Transfer System with Improved Photosensitization Efficiency and Photooxidation Activity.

During the past few decades, fabrication of multistep fluorescence-resonance energy transfer (FRET) systems has become one of the most attractive topics within supramolecular chemistry, chemical biology, and materials science. However, it is challenging to efficiently prepare multistep FRET systems with precise control of the distances between locations and the numbers of fluorophores. Herein we present the successful fabrication of a two-step FRET system bearing specific numbers of anthracene, coumarin, and BODIPY moieties at precise distances and locations through an efficient and controllable orthogonal self-assembly approach based on metal-ligand coordination and host-guest interactions. Notably, the photosensitization efficiency and photooxidation activity of the two-step FRET system gradually increased with the number of energy transfer steps. For example, the two-step FRET system exhibited 1.5-fold higher 1O2 generation efficiency and 1.2-fold higher photooxidation activity than that of its corresponding one-step FRET system. This research not only provides the first successful example of the efficient preparation of multistep FRET systems through orthogonal self-assembly involving coordination and host-guest interactions but also pushes multistep FRET systems toward the application of photosensitized oxidation of a sulfur mustard simulant.

Long-term follow-up of primary silicone oil tamponade for retinal detachment secondary to macular hole in highly myopic eyes: a prognostic factor analysis.

PURPOSE: To investigate the risk factors associated with retinal detachment recurrence after first vitrectomy in high myopic eyes with macular hole retinal detachment (MHRD). METHODS: Patients with high myopic eyes with MHRD who underwent pars plana vitrectomy and silicone oil (SO) tamponade with a follow-up period more than 12 months and more than 3 months after SO removal were included in this retrospective study. Logistic regression was performed to determine the risk factors associated with retinal re-detachment. RESULTS: A total of 45 eyes from 43 patients were included in this study (11 male and 34 female patients). The retinal re-detachment rate after the first removal of silicon oil was 35.5% (16/45) in a mean postoperative follow-up time of 35.64 ± 32.94 months. Complete macular atrophy on fundus photography (odds ratio (OR) = 17.021, 95% confidence interval (95% CI): 2.218-130.609, p = 0.006) was a risk factor for MHRD after SO removal, while internal limiting membrane (ILM) peeling (OR = 0.091, 95% CI: 0.013-0.633, p = 0.015) and duration of SO tamponade (OR = 0.667, 95% CI: 0.454-0.980, p = 0.039) were protective factors. CONCLUSION: For high myopic eyes with MHRD, complete macular atrophy was a significant risk factor for retinal re-detachment after silicon oil removal. ILM peeling and the duration of silicon oil tamponade were protective factors.

Tangeretin Inhibition of High-Glucose-Induced IL-1ß, IL-6, TGF-ß1, and VEGF Expression in Human RPE Cells.

Tangeretin, a natural compound extracted from citrus plants, has been reported to have antiproliferative, antidiabetic, anti-invasive, and antioxidant properties. However, the role of tangeretin in diabetic retinopathy (DR) is unknown. In the present study, we investigated whether tangeretin had any effect on the expression of interleukin 1 beta (IL-1ß), interleukin 6 (IL-6), transforming growth factor beta 1 (TGF-ß1), and vascular endothelial growth factor (VEGF) in human retinal pigment epithelial (RPE) cells under high-glucose (HG) conditions. Our results illustrated that HG levels induced IL-1ß, IL-6, TGF-ß1, and VEGF expression and that tangeretin significantly reduced HG-induced IL-1ß, IL-6, TGF-ß1, and VEGF expression in human RPE cells. Moreover, tangeretin efficiently inhibited the activation of the protein kinase B (Akt) signalling pathway in HG-stimulated RPE cells. Therefore, tangeretin may serve a role in the treatment of DR.

The Role of Apelin/APJ in a Mouse Model of Oxygen-induced Retinopathy.

Purpose: The aim of this study was to investigate apelin and its potential neovascularization role in retinopathy of prematurity (ROP) along with the inhibitory effects of its antagonist. Methods: We used an oxygen-induced retinopathy (OIR) mouse model to explore the progress of ROP. Apelin and angiotensin receptor-like 1 APJ expressions were examined in the retina using immunohistochemistry, quantitative polymerase chain reaction, and Western blot analysis. Additionally, the retina was examined by whole-mount staining to evaluate the retinal vessel area, vessel density, capillary width, and the number and length of tip cells. The expression of the phosphorylated mTOR (p-mTOR), p-PI3K/Akt, and p-Erk signaling pathway was also evaluated using Western blot analysis. Results: Apelin promoted the development of superficial and deep retinal blood vessels, especially for tip cells during the physical development of retinal vessels. Additionally, apelin stimulated the density of the peripheral retinal zone vessels in OIR mice. The apelin and APJ expression levels significantly increased for the OIR model during their hypoxic phase. Next, we found that apelin mRNA levels in the OIR mice peaked at six hours after return to ambient conditions at P12, whereas the APJ mRNA levels peaked later at P17. Furthermore, the expression of p-mTOR, p-Akt, and p-Erk were all up-regulated in OIR mice whereas F13A suppressed them instead. Conclusions: Our results suggest that apelin/APJ signaling pathway is a key factor for hypoxia-induced pathologic angiogenesis, which is a very promising new target for the treatment of ROP.

Gremlin in the Vitreous of Patients with Proliferative Diabetic Retinopathy and the Downregulation of Gremlin in Retinal Pigment Epithelial Cells.

Diabetic retinopathy (DR) is one of the most common causes of blindness globally. Proliferative DR (PDR), an advanced stage of DR, is characterized by the formation of fibrotic membranes at the vitreoretinal interface. The proliferation, migration, and secretion of extracellular matrix molecules in retinal pigment epithelial (RPE) cells contribute to the formation of fibrotic membranes in PDR. Gremlin has been reported to be upregulated in response to elevated glucose levels in the retina of diabetic rat and bovine pericytes. However, the role of gremlin in PDR remains unclear. In the present study, the vitreous concentrations of gremlin were significantly higher in the PDR (67.79 ± 33.96) group than in the control (45.31 ± 12.31) group, and high glucose levels induced the expression of gremlin in RPE cells. The elevated expression of extracellular matrix molecules, such as fibronectin and collagen IV, was significantly reduced by gremlin siRNA in human RPE cells under high-glucose conditions. Thus, gremlin may play a vital role in the development of PDR.

Photoelectron spectroscopy and computational investigations of the electronic structures and noncovalent interactions of cyclodextrin-closo-dodecaborate anion complexes χ-CD·B12X122- (χ = α, ß, γ; X = H, F).

We report a joint negative ion photoelectron spectroscopy (NIPES) and computational study on the electronic structures and noncovalent interactions of a series of cyclodextrin-closo-dodecaborate dianion complexes, χ-CD·B12X122- (χ = α, ß, γ; X = H, F). The measured vertical/adiabatic detachment energies (VDEs/ADEs) are 1.15/0.93, 3.55/3.20, 3.90/3.60, and 3.85/3.60 eV for B12H122- and its α-, ß-, γ-CD complexes, respectively; while the corresponding values are 1.90/1.70, 4.00/3.60, 4.33/3.95, and 4.30/3.85 eV for the X = F case. These results show that the inclusion of B12X122- into the CD cavities greatly increases the electronic stability of the dianions. The effect of electronic stabilization for ß-CD is roughly the same as for γ-CD, both being considerably stronger than that for α-CD. Density functional theory (DFT) based geometry optimization reveals that B12X122- are inserted into CDs increasingly deeper from α-CD to γ-CD. The calculated VDEs and ADEs agree with the experiments well, particularly, reproducing the electron binding energy (EBE) trends. The molecular orbital analyses indicate that the most loosely bound photodetached electrons originate from the guest B12X122- moieties. In addition to a shift of all signals to a larger EBE, significant changes in the signal patterns are observed. At low EBE, this is due to the splitting of highly degenerate B12X122- orbitals, while at high EBE, photodetachment from CD oxygens contributes to the new bands. The guest B12X122- and host CD noncovalent, size-specific interaction based on the independent gradient model (IGM) and energy decomposition analysis (EDA) is dominated by electrostatic interactions. The analysis further unravels unambiguously the existence of dihydrogen bonding and how it affects the total energy that stabilizes the host-guest complexes of CDs·B12H122- compared to the general hydrogen bonding interaction in CDs·B12F122-. This work clearly exhibits strong influences on the electronic structures of dodecaborates upon clustering with CDs, with both size (α-, ß-, and γ-) and molecular (X = H or F) specificities, thus providing critical molecular-level information on the cyclodextrin-closo-dodecaborate interactions of interest to medical applications, e.g., boron neutron capture therapy.