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A novel double-stranded RNA (dsRNA) virus, tentatively named "Paris alphapartitivirus 1" (ParAPV1, OL960006-OL960007), was detected in Paris polyphylla var. yunnanensis plants exhibiting leaf chlorosis and shrinkage symptoms in Yunnan. Its complete genome sequence was determined using Illumina and Sanger sequencing. ParAPV1 has a bipartite genome that consists of dsRNA1 (1,917 bp) encoding the viral RNA-dependent RNA polymerase (RdRp), and dsRNA2 (1,818 bp) encoding the putative coat protein (CP). Sequence comparisons showed that the RdRp and CP of ParAPV1 are most similar to those of pear alphapartitivirus (PpPV2), with 69.97% and 54.21% amino acid sequence identities respectively. Phylogenetic analysis of the RdRp amino acid sequences of ParAPV1 and other partitiviruses showed that ParAPV1 cluster with viruses in a clade containing alphapartitiviruses, and that its closest known relatives are PpPV2 (BBA66577) and rose partitivirus (RoPV, ANQ45203S). Taken together, these results suggest that ParAPV1 should be regarded as a new member of genus Alphapartitivirus in the family Partitiviridae. This is the first report of a partitivirus infecting P. polyphylla var. yunnanensis.

Purpose To investigate whether our modified hydrodissection is safe and efficient in age related cataract surgery. Methods A prospective, randomized, single-blind clinical study was performed in Chongqing Bishan Old Town Hospital from May 16 to August 31, 2022. Age related cataract patients without any other ocular disease were included. They were randomly allocated into modified hydrodissection and traditional hydrodissection groups. Hydrodissection was performed using modified or traditional method. It kept the same procedures as routine in incision, continuous circular capsulorhexis, phacoemulsification, irrigation-aspiration. Hydrodissection time and Oscar score are the main measurement to evaluate the efficiency of the modified method. Descemet membrane detachment, unstable anterior chamber and posterior capsular rupture were the main measurements to evaluate the safety. Results There were 156 patients (age:71.39 ± 7.17 years old; gender: 90 (57.7%) female, 66(42.3%) male) with age related cataract participating in this study. The hydrodissection time was 12.23 ± 1.84s and 18.72 ± 1.69s in the modified hydrodissection group and traditional group, respectively (P༜.001). 89.7% of eyes in modified hydrodissection group achieved Oscar score 5, which was achieved by only 75.6% eyes in traditional group (P = .033). There was no complication occurred in these patients. Conclusions This study demonstrated that the modified hydrodissection was as safe as traditional method but with more efficiency.

The complete genome sequence of a putative novel caulimovirus, tentatively named “Dregea volubilis caulimovirus 1.” (DVCaV1, GenBank accession no. MZ813180), infecting Dregea volubilis in China was determined using high-throughput sequencing (HTS). The complete open circular genomic DNA of DVCaV1 consists of 8,160 nucleotides (nt) and contains seven ORFs that encode a movement protein, an aphid transmission factor, a DNA-binding protein, a coat protein, a polymerase polyprotein, a translational transactivator protein and hypothetical protein, as well as two intergenic regions. This genome structure is typical of viruses of the genus Caulimovirus. Sequence comparisons analyses of the complete genome suggest that DVCaV1 is closely related to strawberry vein banding virus (NC_001725), and shares 43.3-50.3% nt sequence identity with caulimoviruses. Phylogenetic analysis showed that DVCaV1 clustered with viruses of the genus Caulimovirus,with strawberry vein banding virus being the closely related species. These results suggest that DVCaV1 is a new member of the genus Caulimovirusof the family Caulimoviridae. This is the first report of a caulimovirus infecting Dregea volubilis.

The cell adhesion molecule 2 (CADM2) gene has appeared among the top associations in a wide range of genome-wide association studies (GWASs). This study aims to: (1) examine how widespread the role of CADM2 is in behavioural traits, and (2) investigate trait-specific effects on CADM2 expression levels across tissues. We conducted a phenome-wide association study in UK Biobank (N = 12,211–453,349) on 242 psycho-behavioral traits, both at the SNP and the gene-level. For comparison, we repeated the analyses for other large (and high LD) genes. We found significant associations between CADM2 and 50 traits (including cognitive, risk taking, and dietary traits), many more than for the comparison genes. We show that many trait associations are reduced when taking geographical stratification into account. S-Predixcan revealed that CADM2 expression in brain tissues was significantly associated with many traits; highly significant effects were also observed for lung, mammary, and adipose tissues. In conclusion, this study shows that the role of CADM2 extends to a wide range of psycho-behavioral traits, suggesting these traits may share a common biological denominator.

A novel virus, Paris virus 2 (ParV2), was isolated from diseased Paris polyphylla var. yunnanensis, and its complete genome sequence was determined and analyzed. ParV2 is a positive-sense single-stranded RNA (+ssRNA) virus with a genome size of 4,118 nucleotides. The ParV2 genome contains six putative open reading frames (ORFs) that encode proteins with predicted molecular weights of 40.14, 100.26, 7.31, 7.85, 26.09, and 8.77 kDa. The first ORF (ORF1) of ParV2 encodes a putative protein of 40.14 kDa (P40, nt: 20-1,096), whiles the second ORF (ORF2, 888 aa) containing the GDD motif encodes the highly conserved RNA-dependent RNA polymerase protein (RdRP, nt:20-2,683, P100, 100.26 kDa) of viruses in the family Tombusviridae. Multiple sequence alignments analysis showed that the complete genome sequence of ParV2 shares 31.7-55.5% nucleotide sequence identities with viruses in the family Tombusviridae. Ginger chlorotic fleck-associated tombusvirus (GCFaV-1, Accession No. QKE30557) had the highest sequence identity (55.5%) with ParV2. GCFaV-1 also shares 59.2% RdRP and 34.9% CP amino acid sequence identities with ParV2. Sequence comparisons and phylogenetic analysis of RdRP suggested that ParV2 is a novel member of the family Tombusviridae, and its closest known relative is GCFaV-1.

A novel negative-stranded (ns) RNA virus tentatively named "Yunnan paris negative-stranded virus" (YPNSV), was isolated from Paris polyphylla var. yunnanensis plants exhibiting leaf chlorosis and mosaic symptoms in Yunnan. Its complete genome sequence was determined using Illumina and Sanger sequencing. YPNSV has a bipartite genome that consists of a negative-stranded (ns) RNA1 encoding the viral RNA-dependent RNA polymerase (RdRp, p251), an ambisense RNA2 coding for the putative movement protein (MP, p46) and nucleocapsid protein (NP, p39), with the two open reading frames separated by a long intergenic region that is rich in A and U. Sequence comparisons showed that the RdRp, MP, and NP of YPNSV are most similar to those of watermelon crinkle leaf-associated virus 2 (WCLaV-2), with 69.1%, 50.4%, and 60.9% amino acid sequence identity, respectively. Phylogenetic analysis based on deduced amino acid sequences of RdRp and NP showed that YPNSV clustered in a clade with coguviruses and that its closest known relative is WCLaV-2. Based on the above results, YPNSV should be regarded as a new member of genus Coguvirus, family Phenuiviridae.

To compare safety and effectiveness between standard position and adjusted distance pre- and post-anterior capsule of femtosecond laser capsulotomy in white cataracts surgery.Selected white cataracts that underwent LenSx femtosecond laser capsulotomy were randomized into groups A (standard position, with 300 µm symmetrically pre- and post-anterior capsule), B (increased distance with 400 µm symmetrically pre- and post-anterior capsule), and C (unsymmetrical distances of 200 µm pre- and 400 µm post-anterior capsule, respectively). All these surgeries were performed by the same experienced surgeon. Complications, including incomplete capsulotomy and capsule tears, were recorded. In addition, femtosecond capsulotomy and phacoemulsification parameters, IOLs centrality and corrected distance visual acuity were assessed.A total of 113 eyes were included in this study. There were 8 (21.6%) incomplete capsulotomy and 1 anterior capsule tear in group A. Meanwhile, only 2 eyes (5.1%) had incomplete capsulotomy with none showing capsule tear in group B. In group C, only 1 eye (2.7%) had incomplete capsulotomy and no capsule tear occurred. Mean femtosecond laser capsulotomy time was longer in group B compared with groups A and C. Average cumulative dispersed energy, IOL centrality and corrected distance visual acuity were similar in all groups.Appropriate adjustment on femtosecond laser capsulotomy distance by reducing pre-anterior capsule and increasing post-anterior distance, may decrease incomplete capsulotomy and be more effective in white cataracts surgery.Clinical trial registration number: ChiCTR2100043863.

The complete genome sequence of a novel potyvirus, tentatively named "paris virus 1" (ParV1, GenBank accession no. MN549985), infecting Paris polyphylla var. yunnanensis was determined in this study. A single large open reading frame (nt 96-9818) encoding a 3240-aa polyprotein that is predicted to be cleaved into 10 mature proteins was detected in the ParV1 genome. Comparative analysis of the ParV1 genome sequence with those of other potyviruses identified nine cleavage sites and conserved motifs that are typical features of potyviruses. Pairwise sequence comparisons showed that the ParV1 polyprotein shares 49.6-65.1% nucleotide and 47.1-68.9% amino acid sequence identity with viruses of the genus Potyvirus. BLAST analysis revealed that ParV1 shares 65.1% nucleotide and 68.9% amino acid sequence identity with Thunberg fritillary mosaic virus (TFMV, accession no. CAI59123), its closest known relative. These results suggest that paris virus 1 (ParV1) is a new member of the genus Potyvirus.

Synthesis of computed tomography (CT) images from magnetic resonance (MR) images is an important task to overcome the lack of electron density information in MR-only radiotherapy treatment planning (RTP). Some innovative methods have been proposed for abdominal MR-to-CT synthesis. However, it is still challenging due to the large misalignment between preprocessed abdominal MR and CT images and the insufficient feature information learned by models. Although several studies have used the MR-to-CT synthesis to alleviate the difficulty of multi-modal registration, this misalignment remains unsolved when training the MR-to-CT synthesis model. In this paper, we propose an end-to-end quartet attention aware closed-loop learning (QACL) framework for MR-to-CT synthesis via simultaneous registration. Specifically, the proposed quartet attention generator and mono-modal registration network form a closed-loop to improve the performance of MR-to-CT synthesis via simultaneous registration. In particular, a quartet-attention mechanism is developed to enlarge the receptive fields in networks to extract the long-range and cross-dimension spatial dependencies. Experimental results on two independent abdominal datasets demonstrate that our QACL achieves impressive results with MAE of 55.30±10.59 HU, PSNR of 22.85±1.43 dB, and SSIM of 0.83±0.04 for synthesis, and with Dice of 0.799±0.129 for registration. The proposed QACL outperforms the state-of-the-art MR-to-CT synthesis and multi-modal registration methods.

The aim of this study was two-fold: (1) to develop and externally validate a multiparameter MR-based machine learning model to predict the pathological complete response (pCR) in locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT), and (2) to compare different classifiers' discriminative performance for pCR prediction.This retrospective study includes 151 LARC patients divided into internal (centre A, n = 100) and external validation set (centre B, n = 51). The clinical and MR radiomics features were derived to construct clinical, radiomics, and clinical-radiomics model. Random forest (RF), support vector machine (SVM), logistic regression (LR), K-nearest neighbor (KNN), naive Bayes (NB), and extreme gradient boosting (XGBoost) were used as classifiers. The predictive performance was assessed using the receiver operating characteristic (ROC) curve.Eleven radiomics and four clinical features were chosen as pCR-related signatures. In the radiomics model, the RF algorithm achieved 74.0% accuracy (an AUC of 0.863) and 84.4% (an AUC of 0.829) in the internal and external validation sets. In the clinical-radiomics model, RF algorithm exhibited high and stable predictive performance in the internal and external validation datasets with an AUC of 0.906 (87.3% sensitivity, 73.7% specificity, 76.0% accuracy) and 0.872 (77.3% sensitivity, 88.2% specificity, 86.3% accuracy), respectively. RF showed a better predictive performance than the other classifiers in the external validation datasets of three models.The multiparametric clinical-radiomics model combined with RF algorithm is optimal for predicting pCR in the internal and external sets, and might help improve clinical stratifying management of LARC patients.• A two-centre study showed that radiomics analysis of pre- and post-nCRT multiparameter MR images could predict pCR in patients with LARC. • The combined model was superior to the clinical and radiomics model in predicting pCR in locally advanced rectal cancer. • The RF classifier performed best in the current study.

Paris mitovirus 1 (ParMV1) is a positive-sense RNA virus isolated from diseased Paris polyphylla var. yunnanensis plants in Wenshan, Yunnan. The complete genome sequence of ParMV1 consists of 2,751 nucleotides with a genome structure typical of the mitoviruses. ParMV1 genome has a single open reading frame (ORF: 358-2,637 nt) that encodes RNA-dependent RNA polymerase (RdRp) with a molecular mass of 86.42 kDa. ParMV1 contains six conserved motifs (Ι-VΙ) that are unique to mitoviruses. In addition, the 5′and 3′ terminals of the genome have a stable secondary structure, and the reverse complementary sequence forms a panhandle structure. Comparative genome analysis revealed that ParMV1 shares 23.1–40.6% amino acid (aa) and 32.3–45.7% nucleotide (nt) sequence identities with the RdRp of other mitoviruses. The phylogenetic tree inferred from RdRp aa sequence showed that ParMV1 clusters with mitoviruses, and hence should be considered as a new member of the genus Mitovirus in the family Motiviridae. This is the first report of a novel mitovirus infecting Paris polyphylla var. yunnanensis.

A novel virus, Paris virus 2 (ParV2), was isolated from diseased Paris polyphylla var. yunnanensis, and its complete genome sequence was determined and analyzed. ParV2 is a positive-sense single-stranded RNA (+ssRNA) virus with a genome size of 4118 nucleotides. The ParV2 genome contains six putative open reading frames (ORFs) that encode proteins with predicted molecular weights of 40.14, 100.26, 7.31, 7.85, 26.09, and 8.77 kDa. The first ORF (ORF1) of ParV2 encodes a putative protein of 40.14 kDa (p40, nt: 20-1096), whiles the second ORF (ORF2, 888 aa) containing the GDD motif encodes the highly conserved RNA-dependent RNA polymerase protein (RdRP, nt:20-2683, p100, 100.26 kDa) of viruses in the family Tombusviridae. Multiple sequence alignments analysis showed that the complete genome sequence of ParV2 shares 31.7-55.5% nucleotide sequence identities with viruses in the family Tombusviridae. Ginger chlorotic fleck-associated tombusvirus (GCFaV-1,Accession No.QKE30557) had the highest sequence identity (55.5%) with ParV2, and also shares 59.2% RdRp and 34.9% CP amino acid sequence identity with GCFaV-1.Sequence comparisons and phylogenetic analysis of RdRp suggested that ParV2 is a novel member of the family Tombusviridae, and its closest known relative is GCFaV-1.

A novel negative-stranded (ns) RNA virus tentatively named “Yunnan manyleaf paris rhizome negative-stranded virus 1” (YMPrNSV1), was isolated from a Paris polyphylla var. yunnanensis plant exhibiting leaf chlorosis and mosaic symptoms in Yunnan. Its complete genome sequence was determined using Illumina and Sanger sequencing. The genomes composed of three RNA segments (L, M and S) with each one containing a single open reading frame. Based on sequence identity and the presence of typical bunya-like domains/motifs, the proteins encoded by YMPrNSV1 were predicted to be: RNA-dependent RNA polymerase (RdRp), putative movement protein (MP), and nucleocapsid protein (NP). Sequence comparison analyses showed that the RdRp, MP and NP of YMPrNSV1 are highly similar to those of watermelon crinkle leaf-associated virus 2 (WCLaV-2), with 69.1%, 50.4% and 60.9% amino acid sequence identities respectively. Phylogenetic analysis based on deduced amino acid sequences of RdRp and NP suggested that YMPrNSV1 clustered with coguviruses in a clade, and that WCLaV-2 is the known closely related species to YMPrNSV1. Base on the above results, YMPrNSV1 should be regarded as a new member of genera Coguvirus, within the family Phenuiviridae.

Capsicum chlorosis virus (CaCV) is a negative sense ssRNA virus belonging to the genus Orthotospovirus in the family Tospoviridae. It was first discovered in Australia, and then reported in other places including Thailand, China, India, Greece, and United States (Zheng et al.2011; Melzer et al.2014; Chrysoula et al. 2018; Abudurexiti et al. 2019). CaCV infects plants of the families Amaranthaceae, Apocynaceae, Chenopodiaceae, Cucurbitaceae, Amaryllidaceae, Fabaceae and Solanaceae (Basavaraj et al. 2017; Basavaraj et al. 2020). Chromolaena odorata L. (commonly known as Feiji cao in China) is an invasive weedy herb that belongs to the genus Eupatorium (family Asteraceae), and is native to Central America. In May 2020, serrated chlorotic ring and chlorotic ringspots resembling symptoms of orthotospovirus infection (Supplementary Figure 1) was observed on the leaves of C. odorata plants in Honghe County, Yunnan. Three symptomatic leaf samples were collected and double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was performed using antisera targeting Tomato spotted wilt virus (TSWV), Calla lily chlorotic spot virus (CCSV), Capsicum chlorosis virus (CaCV), and Tomato zonate spot virus (TZSV) (Proteintech Group, Inc., China). Buffer solution and healthy leaves were used as a blank and negative controls, respectively. All three symptomatic samples showed positive reactions with only CaCV antiserum (OD450 of 0.315-0.345 relative to 0.078 and 0.076 for healthy plants and the blank control, respectively. The total RNA extracted from the positive samples were further analyzed by reverse transcription-polymerase chain reaction (RT-PCR) using generic primers gL3637 (CCTTTAACAGTDGAAACAT) and gL4435c (CATDGCRCAAGARTGRTARACAGA) which were designed to amplify partial L segment encoding the RNA-dependent RNA polymerase (RdRP) of orthotospoviruses (Chu, et al. 2001). The expected ~800 bp DNA fragment was amplified from all three positive samples by RT-PCR. The amplified DNA was cloned and sequenced. BLAST search of the partial L RNA sequence (GenBank acc. nos. MW964378 to MW964380) revealed that they shared 86.2-97.4% nucleotide (nt) and 97.2-100% amino acid (aa) sequence identities with different isolates of CaCV available in GenBank with CaCV chili isolates (KU941834 to KU941836) from India sharing the highest aa identity of 100%. This confirmed the presence of CaCV in the symptomatic C. odorata plants. The 825 bp complete nucleocapsid protein (NP) of CaCV was also amplified from the samples using primers CaCV-F: ATGTCTAMCGTYAGGCAAC and CaCV-R: TYACACYTCWATAGAWGTACTAG) (Basavaraj et al. 2020), cloned, and sequenced to obtain complete S fragment-nucleocapsid protein (NP) with a size of 825 bp (MW964381 to MW964383). The pairwise comparisons of three fragments showed 85.1-98.3% nt and 87.6-99.6% aa sequence identities with different isolates of CaCV. Maximum-Likelihood phylogenetic trees inferred from the partial RdRP and complete NP aa sequences showed that the C. odorata isolates (CaCV-YN) clustered closely with CaCV tomato isolate from Taiwan and tomato (Yuxi-2013) isolate from China, respectively (Supplementary Figure 1). To our knowledge, this is the first time CaCV has been detected in C. odorata. This study will serve as an important reference for the study of host range of CaCV. Further studies will be required to determine whether thrips could transmit CaCV between C. odorata and other hosts of the virus.

The complete genome sequence of a putative novel potyvirus, tentatively named “Polygonatum kingianum virus 1” (PKgV1), infecting Polygonatum kingianum in China was determined (GenBank accession no. MK427056). PKgV1 has a genome organization that is typical of potyviruses, with a single large open reading frame (nt 123–9236) that encodes a 3037-aa polyprotein that is predicted to be cleaved into 10 mature proteins by virus-encoded proteases. Nine cleavage sites and several conserved motifs were identified in PKgV1 by comparative sequence analysis. Pairwise comparisons revealed that the PKgV1 polyprotein shares 52.0-56.2% nucleotide and 49.2-52.8% amino acid sequence identity with members of the genus Potyvirus. Phylogenetic analysis indicated that PKgV1 clustered with members of the genus Potyvirus and that it is closely related to but distinct from lettuce mosaic virus (LMV, accession no. KJ161186). These results suggest that Polygonatum kingianum virus 1 (PKgV1) is a new member of the genus Potyvirus of the family Potyviridae.

Retinal ischemia/reperfusion injury (IRI) plays a crucial role in the pathophysiology of various ocular diseases. Our previous study have shown that postconditioning with inhaled hydrogen (H2) (HPC) can protect retinal ganglion cells (RGCs) in a rat model of retinal IRI. Our further study aims to investigate potential mechanisms underlying HPC-induced protection. Retinal IRI was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1 h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining, retrograde labelling with cholera toxin beta (CTB) and TUNEL staining, respectively. Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). The phosphorylated Akt was analysed by RT-PCR and western blot. The results showed that administration of HPC significantly inhibited the apoptosis of RGCs and protected the visual function. Simultaneously, HPC treatment markedly increased the phosphorylations of Akt. Blockade of PI3K activity by inhibitors (LY294002) dramatically abolished its anti-apoptotic effect and lowered both visual function and Akt phosphorylation levels. Taken together, our results demonstrate that HPC appears to confer neuroprotection against retinal IRI via the PI3K/Akt pathway.

Retinal ischemia/reperfusion injury (IRI) may cause incurable visual impairment due to neural regeneration limits. Methane was shown to exert a protective effect against IRI in many organs. This study aims to explore the possible protective effects of methane-rich saline against retinal IRI in rat. Retinal IRI was performed on the right eyes of male Sprague-Dawley rats, which were immediately injected intraperitoneally with methane-saturated saline (25ml/kg). At one week after surgery, the number of retinal ganglion cells (RGCs), total retinal thickness, visual function were measured by hematoxylin and eosin staining, FluoroGold anterograde labeling and flash visual evoked potentials. The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), 4-Hydroxy-2-nonenal (4-HNE), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-9, B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in retinas were assessed by immunofluorescence staining, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. As expected, methane treatment significantly improved the retinal IRI-induced RGC loss, total retinal layer thinning and visual dysfunction. Moreover, methane treatment significantly reduced the levels of oxidative stress biomarkers (8-OHdG, 4-HNE, MDA) and increased the antioxidant enzyme activities (SOD, CAT, GPx) in the retinas with IRI. Meanwhile, methane treatment significantly increased the anti-apoptotic gene (Bcl-2) expression and decreased the pro-apoptotic gene (Bax) expression, accompanied by the suppression of caspase-3 and caspase-9 activity. Thus, these data demonstrated that methane can exert a neuroprotective role against retinal IRI through anti-oxidative and anti-apoptotic pathways.

Retinal ischemia/reperfusion (I/R) injury plays a crucial role in the pathophysiology of various ocular diseases. Intraperitoneal injection or ocular instillation with hydrogen (H2)-rich saline was recently shown to be neuroprotective in the retina due to its anti-oxidative and anti-inflammatory effects. Our study aims to explore whether postconditioning with inhaled H2 can protect retinal ganglion cells (RGCs) in a rat model of retinal I/R injury. Retinal I/R injury was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining and retrograde labeling with cholera toxin beta (CTB). Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). Potential biomarkers of retinal oxidative stress and inflammatory responses were measured, including the expression of 4-Hydroxynonenalv (4-HNE), interleukin-1 beta (IL1-β) and tumor necrosis factor alpha (TNF-α). HE and CTB tracing showed that the survival rate of RGCs in the H2-treated group was significantly higher than the rate in the I/R group. Rats with H2 inhalation showed better visual function in assessments of FVEP and PLR. Moreover, H2 treatment significantly decreased the number of 4-HNE-stained cells in the ganglion cell layer and inhibited the retinal overexpression of IL1-β and TNF-α that was induced by retinal I/R injury. Our results demonstrate that postconditioning with inhaled high-dose H2 appears to confer neuroprotection against retinal I/R injury via anti-oxidative, anti-inflammatory and anti-apoptosis pathways.

Glaucomatous optic neuropathy, including axonal degeneration and apoptotic death of retinal ganglion cells (RGCs), eventually leads to irreversible visual impairment. Carbon monoxide (CO) acts as a therapeutic agent against neural injury via its anti-apoptotic effect. Here we hypothesized that low-dose CO inhalation can protect RGCs in a rat model of optic nerve crush (ONC). ONC was performed on adult male Sprague Dawley rats to imitate glaucomatous optic damage. Low-dose CO (250 ppm) or air was inhaled for 1 h immediately after ONC, and all the tests were carried out 2 weeks later. Flash visual evoked potentials (FVEP) and pupil light relax (PLR) were recorded for the assessment of visual function. RGC density was evaluated by hematoxylin and eosin staining and Fluorogold labeling. Retinal apoptotic process was assessed by TUNEL staining and caspase-3 activity measurement. Low-dose CO treatment significantly ameliorated the abnormalities of FVEP and PLR induced by ONC. As expected, the RGC density was increased remarkably by CO inhalation after the glaucomatous optic nerve insult. Moreover, CO treatment after ONC significantly decreased the number of TUNEL-positive cells in ganglion cell layer and attenuated the retinal caspase-3 activity. Low-dose CO inhalation protects RGCs from optic nerve injury via inhibiting caspase-3 dependent apoptosis.

As the commonest complication of diabetes mellitus (DM), diabetic retinopathy (DR) is a neuro-vascular disease with chronic inflammatory. Methane could exert potential therapeutic interest in inflammatory pathologies in previous studies. Our study aims to evaluate the protective effects of methane-rich saline on DR and investigate the potential role of related MicroRNA (miRNA) in diabetic rats. Streptozotocin-induced diabetic Sprague-Dawley rats were injected intraperitoneally with methane-rich or normal saline (5 ml/kg) daily for eight weeks. Morphology changes and blood-retinal barrier (BRB) permeability were assessed by hematoxylin eosin staining and Evans blue leakage. Retinal inflammatory cytokines levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL1-β) were evaluated by immunohistochemistry. Retinal protein expressions of glial fibrillary acidic protein (GFAP) and vascular endothelial growth factor (VEGF) were determined by western blotting. Retinal miRNA expressions were examined by miRNA-specific microarray, verified by quantitative RT-PCR and predicted by GO enrichment and KEGG pathway analysis. There was no significant changes in blood glucose level and body weight of diabetic rats with methane-rich or normal saline treatment, but the decreased retinal thickness, retinal ganglial cell loss and BRB breakdown were all significantly suppressed by methane treatment. DM-induced retinal overexpressions of TNF-α, IL-1β, GFAP and VEGF were also significantly ameliorated. Moreover, the methane treatment significantly up-regulated retinal levels of miR-192-5p (related to apoptosis and tyrosine kinase signaling pathway) and miR-335 (related to proliferation, oxidative stress and leukocyte). Methane exerts protective effect on DR via anti-inflammation, which may be related to the regulatory mechanism of miRNAs.

Optic neurodegeneration, in addition to central nervous trauma, initiates impairments to neurons resulting in retinal ganglion cell (RGC) damage. Carbon monoxide (CO) has been observed to elicit neuroprotection in various experimental models. The present study investigated the potential retinal neuroprotection of preconditioning with CO inhalation in a rat model of optic nerve crush (ONC). Adult male Sprague‑Dawley rats were preconditioned with inhaled CO (250 ppm) or air for 1 h prior to ONC. Animals were euthanized at 1 or 2 weeks following surgery. RGC densities were quantified by hematoxylin and eosin (HE) staining and FluoroGold labeling. Visual function was measured via flash visual evoked potentials (FVEP). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and caspase‑9 and caspase‑3 activity in the retinas, were assessed at 2 weeks post‑ONC. The RGC density of CO + crush rats was significantly increased compared with that of the corresponding crush‑only rats at 2 weeks (survival rate, 66.2 vs. 48.2% as demonstrated by HE staining, P0.01; and 67.6 vs. 37.6% as demonstrated by FluoroGold labeling, P0.05). FVEP measures indicated a significantly better‑preserved latency and amplitude of the P1 wave in the CO + crush rats compared with the crush‑only rats. The TUNEL assays demonstrated fewer apoptotic cells in the CO + crush group compared with the crush‑only group, accompanied by the suppression of caspase‑9 and caspase‑3 activity. The results of the present study suggested that inhaled CO preconditioning may be neuroprotective against ONC insult via inhibition of neuronal apoptosis.

Secondary degeneration is a common event in traumatic central nervous system disorders, which involves neuronal apoptosis and mitochondrial dysfunction. Exogenous methane exerts the therapeutic effects in many organ injury. Our study aims to investigate the potential neuroprotection of methane in a rat model of optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC and administrated intraperitoneally with methane-saturated or normal saline (10 ml/kg) once per day for one week after ONC. The retinal ganglion cells (RGCs) density was assessed by hematoxylin and eosin staining and Fluoro-Gold retrogradely labeling. Visual function was evaluated by flash visual evoked potentials (FVEP). The retinal apoptosis was measured by terminal-deoxy-transferase-mediated dUTP nick end labeling (TUNEL) assay and the expression of apoptosis-related factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3β (pGSK-3β), Bcl-2 associated X protein (Bax) and Bcl-2 extra large (Bcl-xL). Retinal mitochondrial function was assessed by the mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), the mitochondrial DNA (mtDNA) copy number, citrate synthase activity and ATP content. Methane treatment significantly improved the RGC loss and visual dysfunction following ONC. As expected, methane also remarkably inhibited the retinal neural apoptosis, such as the fewer TUNEL-positive cells in ganglion cell layer, accompanied by the up-regulations of anti-apoptotic factors (pGSK-3β, pBAD, Bcl-xL) and the down-regulation of pro-apoptotic factor (Bax). Furthermore, methane treatment suppressed up-regulations of critical mitochondrial components (PGC-1α, NRF1 and TFAM) mRNA and mtDNA copy number, as well as improved the reduction of functional mitochondria markers, including citrate synthase activity and ATP content, in retinas with ONC. Taken together, methane treatment promotes RGC survival and limits retinal mitochondrial dysfunction against ONC insult. Methane can be a potential neuroprotective agent for traumatic and glaucomatous neurodegeneration.